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R&ulation of Lake Champlain and the Upper Richelieu River TECHMW REPORT OF THE ENVIRONMENTAL IMPACT c o m

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C A N A D A

NEW YORK

M I L E S

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K I L O M E T R E S

COVER PHOTOGRAPHS

Top: Flooded approach to ferry dock on Lake Champlain (Net Benefits Com- mittee)

Centre: Seining for pike fry (Environmental Impact Committee)

Bottom: Model testing of a reach of the Richebeu River (Physical Aspects Committee)

INTERNATIONAL CHAMPLAIN-RICHELIEU BOARD

TECHNICAL REPORT

OF THE

ENVIRONMENTAL IMPACT COMMITTEE

December 1977

This r e p o r t i s ded icated t o

James M. MacMartin

191 9-1 977

B i o l o g i s t , Vermont F i s h and Game Department

Member, Environmental Impact Committee,

I n t e r n a t i o n a l Champ1 a in-Riche l i e u Board

He w i l l l ong be remembered by a l l who knew him f o r h i s

p h i l o s o p h i c a l and o p t i m i s t i c ou t l ook on l i f e , h i s vas t

knowledge o f Vermont f i s h and w i l d 1 i f e , h i s phenomenal

memory f o r d e t a i l s , h i s generos i t y t o h i s fel lowman and

h i s deep-seated concern and l o v e f o r h i s f a m i l y , h i s

f r i e n d s , and f o r a l l humanity.

ENVIRONMENTAL IMPACT COMMITTEE

~i 1'1 iam A. Pearce (Co-Chairman)

New York Department o f Environmental Conservat ion Cape Vincent, New York

Doug1 as I. G i 11 esp ie (Co-Chai rman)

Environment Canada, Ottawa, On ta r io

Jean-Pierre Gauth ier

M i n i s t e r e des Richesses N a t u r e l l e s , Quebec, Quebec

James MacMartin

Vermont S t a t e Agency o f Envi ronmental Conservat ion Mon tpe l i e r , Vermont

Andre Bourget

Environment Canada, Ste. Foy, Quebec

Dr. Roger J. Reed

U.S. F i sh and W i l d l i f e Serv ice , U n i v e r s i t y o f Massachusetts Amherst, ~ lassachuse t t s

Dr. John Turk

1 U.S. Geolog ica l Survey, Albany, New York

TABLE OF CONTENTS

DEDICATION

ENVIRONMENTAL IMPACT COMMITTEE MEMBERS

SUMVARY, CONCLUSIONS AND RECOMMENDATIONS

S e c t i o n 1

INTRODUCTION

S e c t i o n 2

STUDY PLAN

2 . 1 Charae t o Conmi t t e e 2 . 2 The C o m m i t t e e ' s Approach t o ' t h e S t u d i e s 2 . 3 P r o c e d u r e 2.4 S t u d y A r e a

4 . 1 F i s h e r i e s

S e c t i o n 3

FISH AND WILDLIFE VALUES

S e c t i o n 4

THE ENVIRONMENTAL IMPACT STUDIES

4 .1 .1 I n t r o d u c t i o n 4 .1 . 2 Methodo logy 4.1.3 E x i s t i n g C o n d i t i o n s 4 .1 .4 P r e d i c t e d E f f e c t s 4 .1 .5 T a r g e t s f o r a N o r t h e r n P i k e Ecosystem

4 . 2 V e g e t a t i o n

4 .2 .1 I n t r o d u c t i o n 4 .2 .2 Methodo logy 4 . 2 . 3 E x i s t i n g C o n d i t i o n s 4 . 2 . 4 P r e d i c t e d E f f e c t s 4 .2 .5 T a r g e t s f o r a V e g e t a t i o n Ecosystem

4.3.1 I n t r o d u c t i o n 4 .3 .2 Methodo logy 4.3.3 E x i s t i n g Condi t i ons 4.3.4 P r e d i c t e d E f f e c t s 4.3.5 T a r g e t s f o r a W a t e r f o w l Ecosystem

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4 .4 .1 Int roduct ion 4 .4 .2 Methodology 4 .4 .3 Ex i s t ing Conditions 4 .4 .4 Predic ted Ef fec t s 4 . 4 . 5 Targets f o r a Furbearers Ecosystem

4 .5 Nut r i en t s - Product iv i ty

4 .5 .1 Int roduct ion 4 . 5 . 2 Methodology 4 . 5 . 3 Ex i s t ing Conditions 4 .5 .4 Predic ted Ef fec t s

Sect ion 5

DISCUSSION

5 .1 Ecosystem Targets 5 . 2 , Base l ine In fo r~na t ion and Future Monitoring 5 . 3 Mi t i g a t i o n 5.4 Other Environmental Concerns

References Appendi x A Di rec t ive t o Envi ronmental Impact Commi t t e e Appendix B Supporting Data Reports

LIST OF TABLES

U. S. Gletl ands He1 d Under Pub1 i c Ownership

Dura t i on o f I nunda t ion a t Assigned Leve ls

Stage Area Data Summary

Change i n Wetland Vegetat ion a t Various Lake Leve ls

LIST OF FIGURES

Loca t ion Map

Loca t ion o f Major Wetlands

Loca t ion o f Wet1 and F i s h e r i e s Study Areas

Loca t ion o f Inshore F i s h e r i e s Study Areas

Vu lnerab le Per iod f o r Nor thern P ike Spawning

Est imated Area o f Wetlands i n R e l a t i o n t o Lake Leve ls

S t e r e o t y p i c P r o f i l e o f Lake Champlain Wetlands

Loca t ion o f Vegeta t ion Study Areas

Aquat ic P l a n t D i s t r i b u t i o n

S t e r e o t y p i c Comparison o f Vegeta t ive Condi t ions

Loca t ion o f Waterfowl Study Areas

Loca t ion o f Furbearer Study Areas

Loca t ion o f N u t r i e n t s - P r o d u c t i v i t y Study Area

SUISWRY, CONCLUSIONS AND RECOMMENDATIONS --

The Environniental Impact Committee developed and conducted a comprehensive s tudy program t o p r o v i d e t h e I n t e r n a t i o n a l Champ1 a in -R iche l i e u Board w i t h i n f o r m a t i o n and recommendations on t h e e l e v a t i o n , frequency and d u r a t i o n o f l a k e l e v e l s t h a t a r e r e q u i r e d t o m a i n t a i n an acceptab le l a k e ecosystem o r even t o enhance t h e environmental management o f Lake Chaniplain and the upper R i c h e l i e u R ive r . That was t h e Committee's f i r s t o b j e c t i v e . I n a d d i t i o n t h e s t u d i e s were meant t o serve as a resource i n f o r m a t i o n bank t h a t w i l l be u s e f u l i n deve lop ing a m o n i t o r i n g program should i t be dec ided t o r e g u l a t e t h e l a k e and r i v e r . They were a l s o i n tended t o p r o v i d e da ta t h a t w i l l be necessary t o conduct an Environment Assessment o r produce an Environmental Impact Statement.

I t was concluded t h a t t h e l a k e ' s and r i v e r ' s wet lands and t h e i r resources, t h e p l a n t s , f i s h and w i l d l i f e , a r e ex t remely impor tan t t o t h e l o c a l economy as w e l l as be ing b i o l o g i c a l l y and a e s t h e t i c a l l y e s s e n t i a l t o t he Lake Champlain bas in .

The s t u d i e s concluded t h a t , of t he four species o f f i s h i n v e s t i g a t e d , t h e n o r t h e r n p i k e was t h e species most a f f e c t e d by changes i n s p r i n g l a k e l e v e l s . Brown bu l lheads were found t o spawn a f t e r t he f l o o d peak; no evidence was found o f ra inbow sme l t spawning i n sha l l ow waters; and no ma jo r i n s h o r e spawning c o n c e n t r a t i o n of w a l l e y e was l oca ted . Three major f a c t o r s i n f l u e n c e d t h e success o f n o r t h e r n p i k e spawning: s u i t a b l e subs t ra te ; water temperature; and l a k e l e v e l s . No r the rn p i k e behav iour w i t h i n t h e l a k e and r i v e r d i d n o t va ry f rom t h a t recorded i n o t h e r s t u d i e s conducted th roughout N o r t h America and Europe.

The n o r t h e r n p i k e was g i ven p a r t i c u l a r a t t e n t i o n i n t h e s t u d i e s because i t was known t h a t i t s e a r l y l i f e stages a r e very dependent upon s p r i n g l a k e l e v e l s . I t i s t h e r e f o r e a good i n d i c a t o r spec ies o f t h e e f f e c t s changes i n l a k e l e v e l s m igh t have on organisms dependent upon wet land ecosystems. I n a d d i t i o n t o be ing a good i n d i c a t o r spec ies i t i s a h i g h l y p r i z e d t rophy f i s h and perhaps t h e key p reda to r spec ies w i t h i n t h e l a k e and r i v e r . Yel low perch popu la t i ons , which p r o v i d e most o f t he s p o r t f i s h harves t , a re t he major food species o f n o r t h e r n p i k e and a re main ta ined a t optimum l e v e l s and s i z e by p i ke .

The wet meadow zone, an area o f grasses and sedges t y p i c a l o f pas tures t h a t border many o f t h e marshes, was t h e most p r o d u c t i v e n o r t h e r n p i k e spawning h a b i t a t . A t t h e p resen t t i m e t h i s zone represents about ] % o f t h e t o t a l wet land area and because o f i t s l o c a t i o n on t h e landward s i d e o f t h e wet land i t i s ve ry v u l n e r a b l e t o changes i n l a n d use p r a c t i c e s . I t i s a l s o the p l a n t conimunity most l i k e l y t o be seve re l y a f f e c t e d by pe r i ods o f l ow s p r i n g f 1 ood peaks.

The swanip f o r e s t t h a t borders t h e l a k e and r i v e r has undergone severe s t r e s s and i n some areas has d i e d - o f f as a r e s u l t of r e c e n t p ro longed pe r i ods o f i nunda t i on .

The spread o f e x o t i c p l a n t s , p a r t i c u l a r l y Euras ian m i l f o i l and wa te r ches tnu t c o u l d be d e t r i m e n t a l t o t h e f u t u r e w e l l - b e i n g o f t h e l a k e and r i v e r . Low l a k e l e v e l s d u r i n g t h e growing p e r i o d c o u l d i nc rease and speed-up t h e e x t e n t o f spread.

The abundance and d i s t r i b u t i o n of m i g r a t o r y b i r d s v a r i e s w i t h water l e v e l s . The success o f n e s t i n g and brood r e a r i n g i s ' dependen t on t h e area and d i s p e r s i o n o f p l a n t com- m u n i t i e s w i t h i n t h e zones o f swamp f o r e s t and emergent vege ta t i on .

Furbearers w i l l be most s e r i o u s l y a f f e c t e d by changes i n l a t e f a l l and w i n t e r l a k e l e v e l s . Muskrat popu la t i ons c o u l d be managed by l a k e l e v e l r e g u l a t i o n .

Most n u t r i e n t s a r e s u p p l i e d t o t h e s tudy marsh f rom t h e f o u r t r i b u t a r y streams d u r i n g s p r i n g h i g h water l e v e l s and pe r i ods o f h i g h p r e c i p i t a t i o n and r u n o f f .

Dur ing l a t e s p r i n g and summer months n u t r i e n t s s t o r e d i n sediments below about 97.0 ft. (29.6 m) suppor t much o f t h e p l a n t community needs when stream f l o w s a r e low. Due t o t h e impermeab i l i t y o f t h e c l a y s o i l s ad jacen t t o t h e marsh area, t h e r e i s l i t t l e exchange o f n u t r i e n t s between those s o i l s and t h e marsh area.

Unusua l ly low waters d u r i n g t h e c r i t i c a l a q u a t i c p l a n t growing season can cause cons ide rab le i nc rease i n rooted-emergent p l a n t g rowth and a decrease i n f l oa t i ng -emergen t p l a n t growth. The 1 a t t e r produces t h e most i n s e c t s (mac ro inve r teb ra tes ) , i m p o r t a n t t o young f i s h and water fowl d i e t s .

The proposed environmental r e g u l a t i o n c r i t e r i a would ensure s u i t a b l e c o n d i t i o n s f o r d e s i r a b l e growth o f bo th r o o t e d and f l o a t i n g semi-emergent p l a n t s . The Vege ta t i ve Stud ies have i n d i c a t e d t h e r e would be no ma jo r changes i n t h e a q u a t i c p l a n t community i f t h e c r i t e - r i a a r e fo l lowed.

The b i o l o g i c a l p r o d u c t i v i t y o f t he l a k e and r i v e r i s n o t a s imp le cause -e f fec t r e l a t i o n s h i p between l a k e l e v e l s and t h e renewable n a t u r a l resources . I t i s a complex web o f i n t e r a c t i n g f a c t o r s some o f which a r e obscure and p o o r l y understood.

Many organisms, p a r t i c u l a r l y those whose e a r l y l i f e stages occur i n t h e wet land and i nsho re areas, a r e dependent upon y e a r l y f l u c t u a t i o n s of wa te r l e v e l s . Lake l e v e l regu la - t i o n cou ld be o f b e n e f i t t o t he l a k e and r i v e r ecosystem through t h e r e d u c t i o n o f extremes which may adve rse l y a f f e c t t he s u r v i v a l of such organisms.

The Environrr~ental Impact Committee b e l i e v e s t h a t i f i t s recommendations a r e f o l l o w e d t h e extreme l a k e l e v e l s c o u l d be reduced and an acceptab le ecosystem main ta ined.

The Committee's recommendations a re :

( 1 ) t h e n a t u r a l seasonal rhy thm of l a k e l e v e l f l u c t u a t i o n s shou ld n o t be d i s rup ted . Be fo re a s t r u c t u r a l c o n t r o l a1 t e r n a t i v e i s i n s t i t u t e d , a l l p o s s i b l e non-s t ruc- t u r a l methods o f f l o o d p r o t e c t i o n shou ld be examined, eva lua ted and implemented, o r e l im inated.

( 2 ) any r e g u l a t i o n p l a n shou ld adhere t o t h e f o l l o w i n g env i ronmenta l r e g u l a t i o n c r i t e r i a :

( a ) When l a k e l e v e l s reach 98.5 f t l / m a i n t a i n l e v e l s a t o r above 98.5 f t f o r a minimum o f 40 davs. H i s t o r i c a l l v t h i s has occur red 18 t imes i n t h e 40 years between 193811977; 15 t imes between A p r i l 1 and A p r i l 21.

( b ) ~ r o m t h e end o f t h e 40 day du ra t i on , l a k e l e v e l s should. f a l l a t a r a t e o f .50 i n c h p e r day and must n o t exceed .75 i n c h p e r day u n t i 1 t h e f i r s t week o f J u n e .

( c ) (ii and (b ) - shou ld occur w i t h an average f requency o f a t l e a s t once i n t h r e e years . - Q-.>id-June, l a k e l e v e l s shou ld be a t o r below 9 6 8 ft. H i s t o r i c a l l y t h ~ s has occur red 25 t imes i n t h e 40 yea rs between 1938-1977. By mid-Ju ly , the l a k e l e v e l shou ld be no l ower t han 95.5 ft. H i s t o r i c a l l y t h i s has occur red 31, t imes f o r t h e yea rs between 1938-19/7 and shou ld f a l l c y 3 d u a l l y t o n o t l ower t han 94.0 f t by November 1. The November 1 l a k e l e v e l s have been 94.0 f t o r h i g h e r 23 t imes i n t h e 40 yea rs between 1938-1977.

( f ) -- During November through February, l a k e l e v e l s shou ld f o l l o w t h e n a t u r a l t r e n d o f r i s i n g b u t shou ld be l i m i t e d ove r t h e f o u r months t o a maximum -- r i s e o f 1.5 f t above t h e 1 November l e v e l . Ta rge t f o r a .5 f t r i s e . - The r i s e between 1 November and February 28 has been 1.5 ft. o r l e s s d u r i n a 26 o f t h e 40 vears between 1938-1977.

( g ) ConsiGtent w i t h env i ionmenta l r e g u l a t i o n c r i t e r i a ( a ) th rough ( f ) and l j i t h i n t h e c o n t e x t o f h i s t o r i c a l h y d r a u l i c da ta on l a k e l e v e l s and r i v e r d i s - - charqes, t h e ecosystem below S t . Jean r a p i d s shou ld be main ta ined. -

( 3 ) l a k e l e v e l s r e g u l a t i o n t o meet n o r t h e r n p i k e requ i rements shou ld be based on a f o r e c a s t system i n c l u d i n g wa te r temperature da ta c o l l e c t e d f rom a sampl ing g r i d .

1; A l l e l e v a t i o n s con ta ined i n t h i s r e p o r t r e f e r t o U.S.G.S. 'datum, which i s 0.37 f t lower than GSC datum.

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( 4 ) any r e g u l a t o r y body should i n c l u d e rep resen ta t i on from t h e s t a t e and p r o v i n c i a l dgenci es respons ib le f o r env i ronmental management, i n c l u d i n g f i s h and wi l d l i f e resources.

( 5 ) t he proposed environmental r e g u l a t i o n t a r g e t s shou ld be considered t e n t a t i v e , s u b j e c t t o re f inement as more i n f o r m a t i o n becomes a v a i l a b l e .

( 6 ) an environmental mon i to r i ng program funded as p a r t o f t h e p r o j e c t should be developed and i n i t i a t e d be fo re t h e commencement o f any c o n s t r u c t i o n and should cont inue a t l e a s t 10 years a f t e r c o n s t r u c t i o n t o assess t h e e f f e c t s o f t h e mod i f i ed l a k e regime on t h e l ake and r i v e r ' s major ecosystem components.

( 7 ) p u b l i c ownership o f key wet lands should be encouraged (about 40% of t h e l a k e wetlands i n U.S. a re now under some form o f p u b l i c ownership) . A f l o o d easement program cou ld be e q u a l l y e f f e c t i v e i n p rese rv ing wet lands and i t i s endorsed as a p o s s i b l e a l t e r n a t i v e .

I <

SECTION 1

INTRODUCTION

H i s t o r i c a l l y ; Lake Champlain and t h e upper R iche l i e u R ive r have exper ienced cons id- e r a b l e v a r i a t i o n s . They have been observed, n o t o n l y i n t h e magnitude o f t h e s p r i n g peaks, b u t i n t h e i r t i n l i n g and t h e d u r a t i o n of v a r i o u s water l e v e l s . P l a n t and animal popu la t i ons i n t he l a k e and r i v e r have responded favo rab l y t o those v a r i a t i o n s t o produce a n a t u r a l environment t h a t has been desc r i bed as "unique i n t h e no r theas te rn p a r t o f No r th America,' i f n o t t h e c o n t i n e n t , i n terms of d i v e r s i t y and p r o d u c t i v i t y " Anon. (1930). B i o l o g i s t s , t h e r e f o r e , a r e r e l u c t a n t t o recommend any changes t h a t w i l l a l t e r t h e normal p a t t e r n s o f l a k e l e v e l f l u c t u a t i o n and the r e s u l t a n t p r o d u c t i v e c a p a b i l i t y o f t h e l a k e and r i v e r .

The "normal" p a t t e r n of l a k e l e v e l behav iour has been random change. Normal ly , yea rs o f h i g h f l oods have been f o l l o w e d by yea rs of low o r moderate peaks and yea rs o f lows f o l l o w e d by moderate o r h i g h peaks. However, d u r i n g t h e p e r i o d o f recorded l a k e l e v e l s (1872-1976) t h e r e have been f o u r pe r i ods of what m igh t be descr ibed as abnoma l l a k e l e v e l s : 1898-1 903, 1933-1 937, 1964-1967, and 1969-1976. Wi th t h e excep t i on o f t h e 1964-1 967 pe r i od , which was a p e r i o d o f low water , a l l were pro longed pe r i ods o f h i g h f l o o d waters. The 1969-1976 p e r i o d was p a r t i c u l a r l y unusual i n t h a t i t p rov ided n o t o n l y a s e r i e s o f yea rs t h a t e x h i b i t e d h i g h s p r i n g peak e l e v a t i o n s b u t a l s o h i g h summer, f a l l and w i n t e r e l e v a t i o n s . It i s d u r i n g these unusual pe r i ods t h a t r e g u l a t i o n c o u l d be most e f f e c t i v e i n t h e management o f t h e l a k e ' s and r i v e r ' s renewable n a t u r a l resources .

Changes t h a t have occur red i n t he qua1 i t y of t he l a k e ecosystem, th rough h i s t o r y , have been a t t r i b u t e d t o developments a long i t s shores. Hanlon (1963), i n an exhaus t i ve rev iew o f a l l known records p e r t a i n i n g t o t h e f i s h e r y o f Lake Champlain r e p o r t s , " I f any one p o i n t i s ou ts tand ing , i t i s t h e apparent f a c t t h a t , r ega rd less o f t h e e x i s t i n g p r a c t i c e s as t o t h e u t i l i z a t i o n o f t h e f i s h e r y resource ( c r e e l l i m i t s , seasons, f i s h i n g methods, e t c . ) , b!e a r e a b l e t o d i scove r no concre te evidence of a harmful d e p l e t i o n o f any spec ies" . However, he cont inues, " I t i s o f course t r u e t h a t some spec ies d i d d e c l i n e and appa ren t l y d isappeared comp le te l y f rom the l a k e . . . The d e c l i n e o f these species, however, was due t o changes i n t he p h y s i c a l c h a r a c t e r i s t i c s o f t h e i r environment and perhaps t o t h e i nc rease o f incompat- i b l e spec ies " . Han lon 's l a s t statement on t h e e f fec t s of phys i ca l changes i n t h e l a k e ' s env i ronment i s t h e c e n t r a l concern o f management b i o l o g i s t s and o t h e r env i ronmenta l i n t e r e s t s .

Throughout t he s t u d i e s , emphasis has been p laced on t h e l a k e ' s and r i v e r ' s wet lands and t h e i r key r o l e i n de te rm in ing t h e p r o d u c t i v e c a p a b i l i t y o f t h e whole ecosystem. The area o f f u n c t i o n a l wet lands i s determined by t h e l a k e e l e v a t i o n f rom i c e - o u t th rough June. I n t h i s r e p o r t wet lands a r e d e f i n e d as lowlands covered w i t h sha l l ow and some,times tempo- r a r y o r i n t e r m i t t e n t waters and i n c l u d e wet meadows, wooded swamps, open marshes and r o o t e d aqua t i cs .

SECTI-ON 2

STUDY PLAN

2.1 Charge t o Committee

The Environmental impact Committee was d i r e c t e d by t h e I n t e r n a t i o n a l Champlain- R i c h e l i e u Board t o develop and undertake t h e necessary s t u d i e s t o i n v e s t i g a t e t h e e l e v a t i o n , frequency and d u r a t i o n o f f l o o d i n g t h a t would be r e q u i r e d t o m a i n t a i n an acceptab le ecosystem o r even enhance t h e environmental management o f t h e l a k e if poss ib le . (Appendix A)

2 . 2 The Cornni t tee 's Approach t o t h e Stud ies

Ttie Cornmi t t e e recogr l i zed t h a t a t tempts t o c o r r e l a t e t h e e c o l o g i c a l r e l a t i o n s h i p s o f t he l ower -o rde r b i o t a w i t h p r e d i c t i o n s o r e v a l u a t i o n s of t h e env i ronmenta l e f f e c t s o f regu- l a t i o n pose t h e g r e a t e s t d i f f i c u l t y because p resen t knowledge o f t h e i r r o l e i n t h e more complex food cha ins i s l i m i t e d . There fore , t h e Committee emphasized i n d i c a t o r spec ies such as n o r t h e r n p i k e , muskrat and m a l l a r d ducks i n i t s a t t emp t t o c o r r e l a t e l a k e l e v e l r e g u l a t i o n w i t h optimum env i ronmental c o n d i t i o n s . Also, p a r t i c u l a r emphasis was g i ven t o changes t h a t might occur i n t h e wet land vege ta t i on .

I t was in iposs ib le t o conduct an ex tens i ve s tudy o f t h e t o t a l system; thus i t was dec ided t h a t t h e s tudy e f f o r t s shou ld be concen t ra ted on those areas cons idered t o be t h e most p r o d u c t i v e and p robab ly t h e most e c o l o g i c a l l y s e n s i t i v e t o changes i n t h e l a k e ' s water l e v e l regime, i . e . , t h e wet lands. Desp i te these l i m i t a t i o n s , t h e Committee b e l i e v e s t h e s t u d i e s have p rov ided s u f f i c i e n t d e t a i l t o assess t h e p o s s i b l e response o f t h e Champlain- R i c h e l i e u ecosystem t o changes i n seasonal l a k e l e v e l s .

2 .3 Procedure

The Environmental Impact Committee was appo in ted by t h e I n t e r n a t i o n a l Champlain- R i c h e l i e u Board on J u l y 11, 1975. A comprehensive s tudy p l a n was developed by t h e Committee on t h e b a s i s o f recommendations made by t h e I n t e r n a t i o n a l Champlain-Richel ieu Eng ineer ing Board (under t h e re fe rence o f 25 March, 1973) and s tudy proposa ls made by t h e Lake Champlain Techn ica l Committeez/ The s tudy p l a n was submi t t ed t o t h e Board and f o l l o w i n g approva l , c o n t r a c t s were l e t by t h e U.S. F i s h and W i l d l i f e Se rv i ce and Environment Canada.

A d d i t i o n a l surveys were i n i t i a t e d , as t he program developed, t o p r o v i d e suppo r t da ta as needed. They i n c l u d e d a d d i t i o n a l ba thymet r i c and topograph ic d e t a i l , and photo- g raph i c coverage o f s e l e c t e d areas. F i s h e r i e s c o n t r a c t o r s p rov ided a d d i t i o n a l con tou r and stage area data which were used by o t h e r c o n t r a c t o r s . Access t o ongoing s t u d i e s o f o t h e r aqencies and u n i v e r s i t i e s was a l s o made a v a i l a b l e t o s tudy c o o r d i n a t o r s . I n f o r m a t i o n on h i s t o r i c l a k e l e v e l s and eng inee r ing des ign was p rov ided t o s tudy groups by t h e Committee ( G i l l e s p i e , 1976) and t h e Phys i ca l Aspects Committee. S i m i l a r l y , i n f o r m a t i o n d e r i v e d f rom the Environmental Impact Committee's s t u d i e s was d i r e c t e d t o t h e Phys i ca l Aspects and Net B e n e f i t s Commi t t e e s .

2/A U. S. i ntera9ency commi t t e e cons i s t i ng o f W p r e s e n t a t i ves f rom U. S. F i s h and W i l d l i f e Serv ice , New York S t a t e and Vermont S t a t e n a t u r a l resource agencies.

C o n t r i b u t o r s t o t h e Committee's f i e l d s t u d i e s were:

F i s h e r i e s

The U n i v e r s i t y o f Quebec a t Montreal New York S t a t e Department of Environmental Conservat ion Vermont S t a t e Agency o f Environmental Conservat ion

Vegeta t ion --

The l l n i v e r s i t y o f Quebec a t Mont rea l Aquatec Inco rpo ra ted , Bu r l i ng ton , Vermont The U n i v e r s i t y o f Massachusetts

Waterfowl-

Vermont S t a t e Agency o f Environmental Conservat ion

Furbearers

Vermont S t a t e Agency o f Environmental Conservat ion

N u t r i e n t s - P r o d u c t i v i t y

The U n i v e r s i t y o f Vermont U.S. Geo log i ca l Survey

A d d i t i o n a l Topographic and Bathymet r ic D e t a i l

Aquatec Inco rpo ra ted Marsha l l , Mack1 i n and Monaghan New York S t a t e Department of Environmental Conservat ion The Uni v e r s i t y o f Quebec a t Montreal

Photograph ic D e t a i l .

Canada Cent re f o r Remote Sensing

The names, p o s i t i o n s and addresses o f a l l 's tudy c o o r d i n a t o r s and s e n i o r f i e l d wcirkers appear i n t h e Suppor t ing Data Reports which a re l i s t e d i n Appendix B.

A l l remote sens ing m a t e r i a l produced by t h e Canada Centre f o r Remote Sensing i n Canada and t h e wet lands o f t he M iss i squo i De l ta , V t . , and K i n g ' s Bay, N.Y., a r e depos i t ed i n t he N a t i o n a l Photo L i b r a r y , Ottawa, Canada.

2.5 Study Area

The s tudy area i s de f i ned , f o r t h e purpose o f these s t u d i e s , by t h e s h o r e l i n e s o f Lake Champlain and t h e R i c h e l i e u R i v e r and extends, as p a r t o f a l o n g (200 mi les1322 km), . narrow (12 mi l e s / l 9 km) v a l l e y , f rom St . Jearl, Quebec t o W h i t e h a l l , New York a long a no r th -sou th a x i s ( F i g . 1 ) .

More than 52,000 acres (21,000 ha) of wet lands, i n c l u d i n g submerged aqua t i cs , a r e l o c a t e d i n t h e l a k e and r i v e r and p r o v i d e va luab le spawning, nursery , and n e s t i n g h a b i t a t f o r the a r e a ' s f i s h and w i l d l i f e resources . Th i s area, a l t hough i t rep resen ts l e s s than 1% o f t h e Lake Champlain dra inage bas in (9,220 sq. mi les/2,388 sq. km.), p rov ides much o f t h e h a b i t a t c r i t i c a l f o r t h e maintenance o f t he l a k e ' s and r i v e r ' s p r o d u c t i v i t y . More than 97% o f t h e l a k e ' s and r i v e r ' s wet lands occur i n t he U.S. and about 40% i s under p u b l i c ownership (Tab le 1 ) . F igu re 2 shows 45 o f t h e major wet lands a long t h e l a k e and r i v e r , from which 16 were s e l e c t e d by the Committee f o r i n t e n s i v e s tudy .

N E W Y O R K

BOUNDARY OF D R A I N A G E B A S I N

LOCATION MAP

New York

Ausable

Kings Bay

Vermont

Dead Creek

East Creek

L i t t l e Creek

Maquam

McCuen

Mud Creek

Sand Bar

; .

TABLE 1

U.S. WETLP.PtQS VELD UMDF.!? PUELIC OWNERSHIP

Federal and S t a t e W i l d l i f e Management Areas

Acres

U.S.

M iss i squo i

N E W YORK

BOUNDARY O f DRAINAGE BASIN

SECTION 3

FISH AND WILDLIFE VALUES

Econoniists f o r many yea rs have a t tempted t o eva lua te t h e r e l a t i v e va lues o f f i s h and w i l d l i f e resources and t h e i r use. Since, i n most ins tances, b i o l o g i s t s a r e n o t a b l e t o p rov ide adequate p o p u l a t i o n da ta f o r most spec ies of f i s h and w i l d l i f e as a b a s i s f o r p r e d i c t i n g changes i n numbers, then abso lu te economic values cannot be determined. The Committee's s t u d i e s d i d n o t d i r e c t l y eva lua te t h e wor th of t h e resources o r p r e d i c t what changes m igh t occur if t h e l a k e l e v e l regime was a1 t e r e d th rough r e g u l a t i o n . However, i n coope ra t i on w i t h t h e U n i v e r s i t y o f Vermont's Department o f Economics, t h e Committee d i d t r y t o c o r r e l a t e water l e v e l c o n d i t i o n s t h a t m igh t a f f e c t wa te r fow l a v a i l a b i l i t y based on s p r i n g p roduc t i on o r f a l l concen t ra t i ons and hun te r success; no c o r r e l a t i o n was e s t a b l i s h e d . I n f a c t , h u n t e r success and h u n t i n g e f f o r t d i d n o t d i f f e r i n yea rs of h i g h wa te r compared t o years o f low water . Th is a n a l y s i s was based on i n f o r m a t i o n c o l l e c t e d by t h e S t a t e o f Vermont Department o f F i s h and Game's q u e s t i o n n a i r e survey i n i t i a t e d i n 1967.

The economic values o f wet lands r e l a t i v e t o t h e i r importance as producers o f f i s h and w i l d l i f e were considered. S ta te , federa l and p r o v i n c i a l agencies were i n t e r v i e w e d t o determine t h e c u r r e n t cos ts o f a c q u i r i n g wet lands f o r t h e management o f f i s h and w i l d l i f e . Costs v a r i e d f rom $75.00 pe r acre t o $1,000.00 pe r acre . The comparable va lues o f t h e wet lands f o r purposes o t h e r than PTsh and w i l d l i f e management were n o t determined.

A c t i n p on beha l f o f t h e Committee, Dr. A. G i l b e r t , o f t h e U n i v e r s i t y o f Vermont, w i t h t h e ass i s tance o f s t a t e personne l , analyzed data c o l l e c t e d d u r i n g a 1975 survey, t o i d e n t i f y t he l e v e l o f expend i tu res i n Vermont and New York f o r h u n t i n g and f i s h i n g i n Lake Chaniplain and assoc ia ted wet lands. A d d i t i o n a l suppo r t i n fo rma t i on was ob ta ined f rom t h e Vermont Department o f F i s h and Game. The 1975 sportsmen expend i tu res , va lues on goods, s e r v i c e s and l i c e n s e fees d i r e c t l y a t t r i b u t a b l e t o h u n t i n g and f i s h i n g on Lake Champlain were about 24.5 m i l 1 i o n d o l l a r s . G i l b e r t (1977).

Comparable i n f o r m a t i o n i s n o t a v a i l a b l e from Canada f o r t h e Quebec p o r t i o n o f t h e l a k e o r r i v e r a t t h i s t ime . However, t h e r e a r e graduate s t u d i e s underway d e a l i n g w i t h t he econornic va lues o f f i s h and w i l d l i f e . T h e i r f i n d i n g s w i l l soon be a v a i l a b l e .

The Committee d i d n o t eva lua te the economic va lue o f t h e resou rce ' f o r educa t i ona l o r a e s t h e t i c purposes. I t shou ld be emphasized t h a t t h i s t y p e o f use and assoc ia ted expen- d i t u r e s a re i n c r e a s i n g y e a r l y as c u l t u r a l demands on the resource i nc rease . A l so t h e economic b e n e f i t s t o t h e l a k e and r i v e r communi t i e s d e r i v e d f rom employment o f ' r e s i d e n t s t o s tudy , manage and p r o t e c t t h e n a t u r a l resources have n o t been es t imated, b u t t hey a r e cons iderab le .

The Committee's s t u d i e s i n Canada d i d p r o v i d e some i n t e r e s t i n g obse rva t i ons on t h e spor tsmen 's use o f t h e resources i n t h e upper R i c h e l i e u R i v e r and M iss i squo i Bay. For example, f i s h i n g de rb ies a r e h e l d annua l l y d u r i n g May and June on t h e upper R i c h e l i e u R i v e r and as many as 500 f i shermen have been counted a long a 12-mi le s t r e t c h o f t h e r i v e r . Most o f these f ishermen come f rom Montreal b u t some f rom as f a r as Sherbrooke and Quebec C i t y .

On M iss i squo i Bay, t he w i n t e r f i s h e r y i s a l s o popu la r . When t h e weather i s f a v o r - ab le , p a r t i c u l a r l y on weekends, as many as 1,000 f i shermen can be counted on t h e bay. S k i l l f u l f i shermen t a k e as many as 500 y e l l o w perch and 20 n o r t h e r n p i k e i n a s i n g l e day. The Quebec Departriient of Tourism, F i s h and Game es t ima ted t h e annual h a r v e s t o f y e l l o w perch from F l iss isquo i Bay i n a s i n g l e y e a r a t about 60 tons .

The s tud ies i n Canada a l s o repo r ted on t h e commercial f i s h e r i e s i n M iss i squo i Bay and t h e upper R i c h e l i e u R ive r . I n 1975, 52 l i c e n s e d f ishermen dec la red gross earn ings of about $103,000 us ing equipment valued a t $87,000. The American e e l f i s h e r y i s by f a r t h e most impor tan t . One f i s h e r y i n p a r t i c u l a r , annua l l y grosses f rom $50,000 - $100,000 and employs a seasonal s t a f f o f about 24. O f i n t e r e s t , t h e upper R i c h e l i e u American ee l f i s h e r y represents about 82, o f Canada's t o t a l annual ee l ca tch.

The importance of t h e l a k e and r i v e r as a source of outdoor r e c r e a t i o n f o r c i t i z e n s o f major urban cent res should a l s o be mentioned. I n t h e Un i ted States, two major c i t i e s , B u r l i n g t o n , V t . and P la t t sbu rgh , N .Y . , a re l o c a t e d on t h e shores o f Lake Champlain, w h i l e i n Canada, Montreal (one o f Canada's two l a r g e s t c i t i e s ) , i s w i t h i n 50 m i l e s o f t h e l a k e and r i v e r .

The economic va lue o f Lake Champlain's f u r ha rves t i s d i f f i c u l t t o e s t a b l i s h s ince t rap1 ines very o f ten extend beyond the boundar ies o f t h e area i n v o l v e d ' i n these s t u d i e s . I n a d d i t i o n , i t i s we1 1 known t h a t t rappers a re g e n e r a l l y q u i t e conse rva t i ve i n t h e i r re - p o r t i n g and may n o t t r u l y r e f l e c t t h e income r e a l i z e d f rom t h e f u r ha.rvest. The s t u d i e s d i d i n d i c a t e t h a t f rom t h e f a l l o f 1976 t o t h e s p r i n g of 1977, t rappers r e p o r t e d a f u r harvest f rom 9 wet lands t o t a l l i n g about $51,000, and t h e a r e a ' s 12 major f u r buyers repo r ted t h e 1975 f u r ha rves t r e t u r n a t about $460,000 f rom t h e l a k e ' s wet lands.

SECTION 4

THE ENVIRONMENTAL IMPACT STUDIES

4.1 F i s h e r i e s

4.1.1 I n t r o d u c t i o n

Lake Charnplain and t h e R i c h e l i e u R i v e r suppo r t a year - round s p o r t and commercial f i s h e r y . Ye l low perch and ra inbow sme l t a r e probab ly t he most i m p o r t a n t spec ies i n terms o f t o t a l numbers harves ted. However, i n terms o f s i z e and a n g l e r i n t e r e s t , t h e n o r t h e r n p i ke , one o f t h e t rophy f i s h of t h e l a k e and r i v e r , i s perhaps t h e most sought a f t e r spec ies .

The l a k e and r i v e r suppo r t 80 spec ies o f f i s h , f i v e o f which have, been i n t r o d u c e d and t h r e e a re now cons idered r a r e . Fourteen of t h e e i g h t y species a r e c l a s s i f i e d as game f i s h .

Commercial f i s h i n g w i t h i n t he l a k e and r i v e r i s n o t as impor tan t as i t p r e v i o u s l y has been, b u t i t s t i l l p rov ides a s i g n i f i c a n t secondary source o f income f o r many o f t h e a r e a ' s r e s i d e n t s . The c a t c h i n c l u d e s : t h e American e e l , w h i t e f i s h , carp , suckers, channel c a t f i s h , pumpkinseed, b l a c k c rapp ie , rock bass and minnows. Today, t h e f i s h e r y f o r t h e American e e l i s p robab ly t h e most s i g n i f i c a n t commercial o p e r a t i o n b u t as s p o r t f i s h i n g pressure increases t h e demand f o r , and t h e commercial ha rves t o f , minnows f o r b a i t w i l l grow.

The h i s t o r i c a l r eco rds of Lake Champlain f r e q u e n t l y r e f e r t o t h e q u a l i t y o f i t s f i s h e r y and p r o v i d e cons ide rab le i n f o r m a t i o n on changes t h a t have taken p l a c e i n a n g l e r success and t h e types o f f i s h i n g gear used ove r t h e years . For example, i n a 1929 Lake Champlain survey r e p o r t by t h e New York S t a t e Conservat ion Department, t h e r e i s a rep ro - d u c t i o n o f a 1776 niap o f t he l a k e showing a salmon f i s h e r y a t t h e n o r t h end o f t h e l a k e . Th is species was l a t e r r e p o r t e d i n Thompson's Vermont t o be scarce by 1842.

The most r e c e n t advance i n t h e management o f t h e l a k e ' s f i s h e r y i s t h e coope ra t i ve e f f o r t o f New York and Vermont, i n apreement w i t h t h e Prov ince o f Quebec, t o r e - e s t a b l i s h a salnlonid f i s h e r y . S ince 1972, t h e r e have been severa l p l a n t i n g s o f l and locked salmon, s tee lhead and l a k e t r o u t , and fo l low-up e v a l u a t i o n s t u d i e s cont inue. Cons ide ra t i on has a l s o been g i ven t o t h e i n t r o d u c t i o n o f brook and brown t r o u t .

Planned s tock ings o f A t l a n t i c salmon i n Lake Champlain may s u c c e s s f u l l y r e s t o r e salmon between t h e A t l a n t i c Ocean and t h e l a k e . Th i s would r e q u i r e f i s h e r i e s managers and o the rs t o cons ide r a means o f t r a n s p o r t i n g o r f o r a l l o w i n g salmon t o surmount dams on t h e R iche l i e u R ive r .

4.1.2 Methodology

The Lake Champlain Technical Committee, d u r i n g the development o f t h e b a s i c Lake Charnplain s tudy requirements, recogn ized i t was imposs ib le t o conduct an i n v e s t i g a t i o n on a l a r g e number o f spec ies w i t h i n t h e e s t a b l i s h e d t i m e frame. There fore , i t recommended t h a t t h e s t u d i e s shou ld focus on f o u r spec ies : n o r t h e r n p i ke , brown bu l lheads, w a l l e y e and, ra inbow smel t ; a l l cons idered t o be p o s s i b l y d i r e c t l y a f f e c t e d by changing l a k e l e v e l s . The Environmental Impact Committee s e l e c t e d t h e n o r t h e r n p i k e as an i n d i c a t o r o f t h e e f f e c t s t h a t changes i n s p r i n g l a k e l e v e l s n i igh t have on i nsho re f i s h p r o d u c t i o n b u t i n f o r m a t i o n on t h e o t h e r t h r e e spec ies was a l s o obta ined.

A l i t e r a t u r e rev iew of s t u d i e s conducted i n o t h e r p a r t s o f No r th America and Europe i n d i c a t e d t h e n o r t h e r n p i k e r e p r o d u c t i v e p o t e n t i a l and r e l a t i v e abundance a re dependent on seasonal water l e v e l f l u c t u a t i o n s and a v a i l a b l e spawning h a b i t a t . They spawn i n ve ry sha l - low water , l e s s than two f e e t (60 cm), s t a r t i n g when s p r i n q f l o o d waters a r e on t h e r i s e . The spawning r u n i s r e p o r t e d t o l a s t about 12 t o 18 days; i n c u b a t i o n o f t h e eggs, 12 t o 14 days; and y o l k sac a b s o r p t i o n by l a r v a e , about 5 t o 10 days. Mob i l e l a r v a e r e q u i r e d about 12 days t o move o u t o f t h e spawning area i n t o t h e l i t t o r a l zone. Dur ing t h i s c r i t i c a l phase they a r e h i g h l y v u l n e r a b l e t o changes i n t h e i r environment. The Committee concluded t h a t the bas i c l i f e c y c l e requ i rements o f a l l organisms dependent upon s p r i n g water l e v e l s c o u l d be met i f those o f t h e n o r t h e r n p i k e were s a t i s f i e d .

The s tudy areas were s e l e c t e d t o p rov ide a r e p r e s e n t a t i v e sample o f t h e l a k e ' s wet lands and i nsho re areas ( F i g s 3 and 4 ) . Fac tors taken i n t o c o n s i d e r a t i o n were: importance as recogn ized spawning areas, s i z e , g rad ien t , l o c a t i o n , and v e g e t a t i v e compos i t ion .

The wet land f i s h e r y s t u d i e s were organ ized i n t o t h r e e phases of f i e l d s tudy : ( 1 ) a d u l t spawning ( 2 ) egg and immobi le f r y sampl ing and ( 3 ) mob i l e f r y l j u v e n i l e sampl ing. 'The i nsho re f i s h e r y s t u d i e s were 1 i m i t e d t o i n v e s t i g a t i o n s of spawning a c t i v i t y .

Eggs and f r y were sampled i n a l l v e g e t a t i v e types u s i n g Forney boxes, supplemented by long-handled scap nets , and b u r l a p t r a y s . Seines and smal l t r a p n e t s were used as t h e f r y became mob i l e and i nc reased i n s i z e . The e f f i c i e n c y o f t h e cap tu re techniques decreased as t h e young of t he y e a r moved f rom t h e marshes i n t o t he l i t t o r a l zone o f t he l a k e and r i ve r .

Nor thern p i k e data were c o l l e c t e d on t h e number, l eng th , sex and sp?.wning c o n d i t i o n ; s c a l e samples were taken and a l l a d u l t s tagged a n d l o r f i n c l i p p e d .

Du r ing t h e f i e l d s tud ies d a i l y records were kep t o f temperatures ( a i r and wa te r ) and water ,depth. P e r i o d i c sampl i n g i n t h e s tudy areas 'cont inued t o determine young o f t he

y e a r yrowtn ana movement, and a d u l t spawning success.

Brown b u l l h e a d i n v e s t i g a t i o n s were conducted d u r i n g May and e a r l y June 1976. Attenipts were made t o v i s u a l l y l o c a t e spawning and n e s t i n g a c t i v i t y . Eggs, fry numbers, and p h y s i c a l da ta were a l s o recorded.

A d u l t wa l leyes were captured i n 1976 and da ta s i m i l a r t o t h a t recorded f o r a d u l t n o r t h e r n p i k e c o l l e c t e d . Sampling f o r wa l l eye eggs and f r y was conducted i n l a t e A p r i l and e a r l y May o f 1976 and 1977.

Small mesh g i l l ne t s were used d u r i n g t h e l a s t week o f A p r i l 1976 t o sample t h e smel t p o p u l a t i o n and b u r l a p t r a y s were p laced on s e l e c t e d s h o r e l i n e areas t o t r y t o c o l l e c t eggs i f t h e r e was shore spawning a c t i v i t y .

Labora tory examinat ions were made o f a l l t h e m a t e r i a l s and data c o l l e c t e d i n t h e f i e l d . No r the rn p i k e sca les were read,aoes, and growth de te rm ina t i ons made and stomach c o n t e n t analyzed.

A l l da ta generated f rom f i e l d and l a b o r a t o r y s t u d i e s were coded and recorded on s tandard forms, and en te red f o r computer s torage, p rocess ing and analyses. Data f rom t h i s p r o j e c t a re s t o r e d on magnet ic tapes and d i s k s f o r f u t u r e re fe rence .

4.1.3 E x i s t i n g c o n d i t i o n s

The s t u d i e s d i d n o t p rov ide s u f f i c i e n t i n f o r m a t i o n on t h e spawning behav io r o r h a b i t a t requirements o f brown b u l l h e a d o r wa l l eye needed t o assess t h e e f f e c t s t h a t l a k e l e v e l f l u c t u a t i o n s have on p r o d u c t i v i t y . They d i d i n d i c a t e , however, t h a t c e r t a i n wet lands c o n t r i b u t e s i g n i f i c a n t l y t o t he l a k e ' s p o p u l a t i o n o f bu l l heads and t h a t spawning occurs a f t e r t h e s p r i n g f l o o d . The wa l l eye i n v e s t i g a t i o n i n d i c a t e d t h a t t h i s spec ies spawns ove r a wide range o f depths.

C A N A D A - - _ - - - - - -----

N E W Y O R K

BOUNDARY OF

I CARMEN'S MARSH

15 SOUTH HERO

18 M A L L E T T S CR.

26 OTTER CR.

31 CHAMPLAIN NARROWS

32 AUSABLE MARSH

33 KINGS BAY

42 SOUTH BAY

43 BLEUR ST.

45 PIKE R.

N E W Y O R K

BOUNDARY OF

No proof of inshore rainbow smelt spawning. was obtained. Ear l ie r s tudies indicated t ha t the lake smelt population spawns in deep water where lake level f luc tua t ion would have no e f f e c t .

Northern pike began t o move towards the spawning areas by ice-out , when surface water temperatures were about 34F ( 1 C ) . They spawned in water depths of 6 t o 24 in . (general ly l e s s than 16 i n . ) during ear ly April both years and t h i s a c t i v i t y las ted between 10 and 14 days when lake leve ls were a t or near t h e i r peaks (1976 - 101.5 ft/30.9m; 1977 - 100.2 f t / 30 .5 m ) . Surface water temperatures during the spawning periods varied between 39F and 56F (4C and 13C) and, in 1977, a sudden drop in temperature over a 5-day period, interrupted the cont inui ty of spawning a c t i v i t y and may have resul ted in egg mortal i ty .

Eggs were deposited on a wide var ie ty of subs t ra te types; flooded meadows, pastures and shrub-grass provided the highest egg counts. Flooded woodlands, where grasses had become es tab l i shed , were u t i l i z ed more frequent ly than areas covered with l e a f l i t t e r .

During 1977, northern pike eag hatching f i r s t occurred on April 12. The newly hatched larvae ( 0 . 2 4 and 0.47 i n ; 6 and 12 mm), became attached t o the vegetation by means of an adhesive gland on t h e i r heads and remained there during yolk sac absorption f o r 6 t o 10 days. They began feeding on plankton and then converted t o insec t larvae. By 0.8 in (20 111ni) they were su f f i c i en t l y mobile t o move out of the spawning grounds with the receding water. In 1976 and 1977, t h i s occurred on May 10 and May 13 respect ivelv. As young of t he year- (77 nlmTL) they fed on f i s h , mainly ye1 low perch, pumpkinseed, minnows, banded k i l l i f i s h , redfin p ickere l , and other northern pike.

In summary the 1976-1 977 s tud ies revealed the following sequence of events:

1 . Sexually mature pike began t o move in to the spawning areas by ice-out. 2. Spawning commenced in ear ly April and las ted 10 t o 14 days. 3. Incubation las ted 15 t o 19 days. 4. Larval development t o the mobile s tage required 6 t o 10 days. 5. Free swimming young of the year began t o leave the spawning area by May 10 and 13.

Figure 5 shows the maximum time span when northern pike a r e highly vulnerable t o changes in t h e i r environment. The phases a re :

incubation 1 arval

development

14 days + 19 days + 10 day - 43 days -

The Committee concluded t ha t the following conditions a r e required f o r the maintenance of a good northern pike population within the lake and r i ve r :

1 . Spawning habi ta t with a low gradient consis t ing of flooded meadows and waterways. Vegetation composed of grasses , sedges, weeds and shrub-grass assoc ia t ions .

2. Water l eve ls r i s i ng t o inundate the spawning hab i t a t , during ice-out. 3. Inundation of spawning hab i t a t f o r a period of a t l e a s t 40 days with no widely

f luc tua t ing water l eve l . 4. Nater temperatures between 39F t o 56F (4C t o 13C) during t h i s 40-day period. 5. Water l eve ls f a l l i n g a f t e r the 40-day duration a t a r a t e of .50 inch per day

not t o exceed .75 inch per day. 6 . These conditions should occur on the average of a t l e a s t once every th ree years .

A review was made of the U.S. Geological Survey records of lake leve ls . The data col lected a t the Rouses Point , N . Y . s t a t i on between 1938 and 1976 were used t o determine how these c r i t e r i a had been met h i s t o r i ca l l y and what e levat ions wo~lld best s a t i s f y them. Lake leve ls a t 98.5, 99.0, 99.5 and 100.0 f t (30.0, 30.2, 30.3, and 30.5 m ) were selected and the durations were determined when those leve ls prevailed.

F I G U R E 5

V U L N E R A B L E P E R I O D FOR N O R T H E R N PIKE SPAWNING

-

lake surface

(egg deposition to hatching)

DAYS

Table 2 shows t h a t in the 39-year period, only elevat ion 98.5 f t (30.0 m ) s a t i s f i e d the 40-day duration with any degree of regular i ty (17 years out of the 39). Also, s ince 1968, the occurrence of a 40-day duration has been more prevalent even a t the 99.0 f t (30.2 m) l eve l . Accordingly, e levat ion 98.5 f t (30.0 m ) was selected on the basis of the analysis and the findings of the Vegetation Studies as the t a rge t level needed t o maintain the northern pi kc population.

The Lake Champlain and upper Richelieu River wetlands were mapped to provide topographic data for the determination of areas occupied by d i f f e r en t e levat ions during the spring flood. I t was decided t o inap a t contours of one half m (1 .6 f t ) because of t he number of wetlands t o be mapped and the cost . Stage area data were calculated fo r 32 of the wetlands (Table 3) from the maps, and additional data col lected by the Fisheries and Vegetation Studies .

The t o t a l area of wetlands a t e levat ion 101.7 f t (31.0 m ) i s about 29,000 acres (11 ,736 ha ) . This e levat ion was approached in 1976 (101.5 f t ) and exceeded only once (101.8 f t ) in 1903. More meaningful t o the s tud ies in the area f a l l i n g below 100.0 f t ( 30 .5 111) s ince i t was ant icipated t h a t in order t o s a t i s f y the f i she r i e s requirements peaks inust be above 98.5 f t (30.0 m ) . Fig. 6 shows the estimated area of wetlands ava i lab le a t d i f f e r en t e leva t ions .

4.1.4 Predicted e f f ec t s

The s tud ies have defined the c ~ n d i t ~ i o n s necessary f o r the maintenance of adequate stocks of northern pike within the lake and r i ve r . The Committee believes t h a t i f those conditions prevai 1 , an acceptable ecosystem wi 11 be maintained.

Spawning subs t ra te ( i . e . grasses , sedges and the shrub-grass community) wil l be dependent upon the type of plant succession t h a t occurs and any e f f ec t s caused by changes in land-use prac t ices . Wetlands a r e , by t h e i r nature, dynamic communities constantly undergoi'ng change. The r a t e of change i s dependent upon water level .

I f the conditions tha t have occurred s ince 1968, continue, i t i s expected t h a t there wil l be a continuation of the s h i f t of aquat ic and wetland vegetation inland as recorded in the Vegetation S tudies . This s h i f t wi l l be of importance t o northern pike spawning s ince the bes t spawning hab i t a t , i . e . the wet meadow zone, wil l be affected.

The Co~linli t t e e be1 ieves tha t i f the water level c r i t e r i a recommenced by the Fisheries Studies a r e adhered t o , the maintenance of a good northern pike population wil l be assured. Also, the Vegetation Studies indi'cate t ha t the c r i t i c a l wet meadow zone wi l l be maintained unless i t i s developed fo r other land-use purposes.

However, three very important c r i t e r i a must be met:

1. The preservation of desirable spawning subs t ra te ; 2 . Water levels t h a t inundate the spawning subs t ra te ; and 3. A duration of inundation for a t l e a s t 40 days t o enable spawning t o occur, eggs

t o incubate and larvae t o develop t o the f r ee swimming stage.

4 .1 .5 Targets f o r a northern pike ecosystem

1 . When the lake reaches 98.5 f t maintain leve ls a t o r above 98.5 f o r a minimum of 40 days.

2 . Froni end of 40-day duration lake levels should f a l l a t a r a t e of .50 in . per day and must not exceed .75 i n . per day unt i l the f i r s t week in June.

3. 1. and 2. must occur with an average frequency of a t l e a s t once every th ree years .

4 . 2 V e g e t a t j n

4.2.1 Introduction

Throughout a1 1 the s tud ies , wet1 ands and t h e i r importance t o the productive capabi l - i t y of the lake and r i ve r have been s t ressed . They derive t ha t importance by being key

TABLE 2

DURATION OF INUNDATION AT ASSIGNED LEVELS ( P e r i o d March, A p r i 1 , May)

95.5 (30 .0) 99.0 (30.2) 99.5 (30.3) 100.0 (30.5)

year 31 Days Days Days Days

3' o n l y yea rs recorded when l a k e l e v e l s reached o r exceeded 98-.5 f t (30.0 rn)

x - s a t i s f i e s 40 days ( o r more) d u r a t i o n

TABLE 3

STAGE AREA DATA SUMMARY FOR 32 MAJOR LAKE CHAMPLAIN WETLANDS

Wet land Area T o t a l Ac res a t

101.7 (31 .O) 100.0 (30 .5 ) 98.5 (30.0) ' 97.0 (29.5)

M i s s i squo i R i v e r O t t e r Creek The Narrows Scornoti on Sandbar Refuge Ausab le Marsh K ings Bay C l i 11 enbeck & P a l ~ n e r s Lapalls Bay Ke l 1 y Bay Flon t y Bay E a s t Creek W o o d r u f f Pond Ma1 l e t t s Creek L a m o i l l e R i v e r Jo rdans S tevens Brook Chininey P o i n t Sou th Bay Sou th Hero H i b b a r d s Bay Champ1 a i n A i r p o r t P e l o t s Bay T i c o n d e r o g a Bay Putnam Creek G u l l wagga Bay blickharn Marsh L a p l a t t e R i v e r Thorp Brook The C a r r y Rouses P t . N o r t h Lapham I s l a n d - - - --

TOTALS

F I G U R E 6

30 r ESTIMATED AREA OF 32 WETLANDS IN RELATION TO LAKE LEVELS

LAKE ELEVATION

sources o f food and cover f o r many p l a n t and animal species, p a r t i c u l a r l y d u r i n g t h e an imals ' c r i t i c a l e a r l y 1 i f e stages. T h e i r p r o d u c t i v e c a p a b i l i t y i s d i r e c t l y r e l a t e d t o t h e abundance and d i v e r s i t y of t h e species they support . O f a l l ecosystems found w i t h i n t h e Lake Champlain watershed, wet lands a re t h e most p r o d u c t i v e of p l a n t and animal l i f e .

W i t h i n t h e wet lands, change i s t h e r u l e . They a r e dynamic communities undergoing cons tan t change i n response t o a v a r i e t y o f p h y s i c a l , chemical and b i o l o g i c a l pressures. When openings i n cover occur, new species become es tab l i shed . Thus, a wet land community i s cha rac te r i zed by cons tan t change r a t h e r than s t a b i l i t y .

The proqress of succession i n a wet land i s u s u a l l y i n response t o any environmental change t h a t a f f e c t s water depth o r du ra t i on , and a l t e r s t h e s o i l a e r a t i o n . The d i r e c t i o n o f change can t h e r e f o r e proceed f rom an aqua t i c h a b i t a t towards a t e r r e s t r i a l one, o r v i c e versa. Normal ly, t h e p ioneer vascu la r p l a n t s a r e submerged aqua t i cs t h a t may grow i n any depth o f water where t h e r e i s adequate l i g h t pene t ra t i on . Nearer shore, they a r e l i m i t e d by a zone o f f l o a t i n g - l e a v e d species t h a t shade them ou t . F loa t i ng - leaved p l a n t s cannot advance i n t o t h e submergent zone unless water l e v e l s f a l l , a l l o w i n g them t o e s t a b l i s h r o o t systems. I n s t i l l sha l lower water emergent species predominate and accumu- 1 a t i o n s o f sediment, ( p a r t i a l l y decomposed o rgan ic m a t e r i a l ) , b u i l d up. Development o f t h e swamp f o r e s t i s s u b j e c t t o i n t e r m i t t e n t o r temporary f l ood ing and 'usua l l y r e s u l t s i n b e t t e r s o i l a e r a t i o n and t h e c r e a t i o n of a h a b i t a t s u i t a b l e f o r t h e i n v a s i o n o f up land species, such as grasses ( F i g . 7 ) .

Lake Champlain and t h e upper R i c h e l i e u R i v e r wet lands suppor t a wide d i v e r s i t y of vascu la r p l a n t s . F i ve zones were recogn ized i n t h e s tud ies . The submergent zone, w i t h p l a n t s t h a t grow comple te ly under t h e water surface, i nc ludes : water -ce lery , m i l f o i l , waterweed, coonta i 1 and bushy pondweed. The f l o a t i n g zone c o n s i s t s of p l a n t s w i t h f l o a t i n g leaves, anchored w i t h a r o o t system i n t h e subs t ra te . I t inc ludes water l i l i e s and water s h i e l d . The emergent zone cons i s t s of c a t t a i l , arrowhead, burreed, and a v a r i e t y o f sedges. They a re t h e aqua t i c p l a n t s w i t h r o o t s and lower p o r t i o n o f t h e i r stems and leaves under- water, b u t t h e i r tops, i n c l u d i n g f l ower ing p a r t s , a re u s u a l l y borne above t h e water sur face. The swamp f o r e s t i s a zone c o n s i s t i n g , i n p a r t , o f maples, ash, e lm and w i l l o w w i t h an unders to ry o f f e r n and crowfoot. I n t h e upper R i c h e l i e u R i v e r t h i s zone a l s o suppor ts r e l i c stands o f swamp w h i t e oak. Two areas have been recommended as I n t e r n a t i o n a l B i o l o g i c a l

,Programme (IBP) reserve s i t e s , Ash I s l a n d and South R ive r because they a r e cons idered b i o l o g i c a l l y impor tan t f o r t h e p r e s e r v a t i o n o f stands o f swamp w h i t e oak a t t h e i r no r the rn - most l i m i t .

The l a k e and r i v e r wet lands a l s o c o n t a i n a t r a n s i t i o n zone - t h e wet meadow, an a c t i v e zone t h a t i s r e g u l a r l y i n f l u e n c e d by man's a c t i v i t i e s . It i s assoc ia ted w i t h sea- s o n a l l y wet s o i l s and c o n s i s t s o f rushes and grasses such as reed canary grass, c u t grass, w i l d m i l l e t and manna-grass. The wet meadow may i n t e r f a c e d i r e c t l y w i t h t h e emergent zone b u t u s u a l l y they are separated by t h e swamp f o r e s t . T h i s i s a c r i t i c a l zone f o r many organisms, p a r t i c u l a r l y those w i t h an e a r l y 1 i f e s tage vu lne rab le t o unusual changes d u r i n g the s p r i n g f l o o d pe r iod . Nor thern p i k e spawning and l a r v a l r e a r i n g occurs most f r e q u e n t l y i n t h i s zone. The wet meadow zone i s most s e n s i t i v e t o water l e v e l f l u c t u a t i o n s i n c e i t represents t h e t r a n s i t i o n between t e r r e s t r i a l and aqua t i c h a b i t a t s . Increased water l e v e l s r e s u l t i n t h e r a p i d i n v a s i o n o f aqua t i c p l a n t s w h i l e decreased water l e v e l s f a v o r t h e i nvas i on o f up1 and species.

Much o f t h e l a k e and r i v e r wet meadows a r e grazed by l i v e s t o c k . Dur ing yea rs of low l a k e l e v e l s they a r e f r e q u e n t l y c u t f o r hay and o f ten brought under c u l t i v a t i o n . A v a i l a b l e l a n d use data show t h a t segments o f t h e wet.meadow zone have been l o s t t o t h e l a k e ecosystem as a r e s u l t o f i n t e n s i v e l and dra inage p r a c t i c e s and changes i n c rop prac- t i c e s . I n some areas, bo rde r ing t h e l a k e and r i v e r , t h e wet meadow has been rec la imed f o r urban o r r e c r e a t i o n a l development.

4 .2.2 Methol odogy

Deta i 1 ed vege ta t i on s t u d i e s were .conducted i ti 11 ' ~ e i ' y o r k and Vermont wet!ands and t h e wet lands o f M iss i squo i Bay ( F i g . 8 ) . I n a d d i t i o n , t h e U n i t e d Sta tes examined i n l e s s d e t a i l an a d d i t i o n a l 31 wet lands i n New York and Vermont w h i l e t h e Canadian s t u d i e s i n t e - g ra ted t h e work done i n t h e upper R i c h e l i e u i n 1974 and 1975.

F I GURE '7

GRASS a SEDGE MEADOW

Monno-g ross G lyce r l a spp. gg Pan ic Gross Ponicum spp.

Wild M i l l e t Ech inoch loa spp. SWAMP FOREST

Wi ld Rye E l y m u r Woody Species

F ra t i nus rpp. EMEMERENT PLANTS U- rpp. Scou r i ng Rush Equ iae tum Sol ix spp. - C a t t o i l J u n c u s SOP. -- Buttonbush

Trpha SUPP. Cephalanthus

Bu l rush Sc i rpus sop. Herbaceous Species Three -way Sedge Du l i ch ium

S e n s i t i v e Fern O n o c l e q B u r r e a d Spargonium Spp Crow foo t Ronunculus Fowering Rush B u t o n u r Moneywor t Lvs imach ia W i l d R i ce Z i z a n i a sop. FLOATING PLANTS

Spike Rush E leocho r i r spp. Arrowhead S agittaria - .Water L i l y Nymphoea rpp. Wotr r Plantain A- rpp. Spo t te rdock Nuphor rep. P ickere l Weed Pon tede r i o Wo t r r Sh le ld B r o r o n i ~ Dock Rumer sop. - Duck Weed Lemna sw. - Smartwood- Polygonum rpp. Water Meal W o l f f i a spp. A r r o w Arum Pe l t ond ra Water Chestnut Tropa Sweet F lag Aco ru r

SUBMERSED PLANTS

Coon to i l Ceratophylum spp. W o t e r r e r d M i l f a i l

UelkL! Myr iophy ium sop.

Pond Po tamage ton rpp. Water - c e l e r y Vo l l i sne r l a Water Mar l go ld Mega lodona ta Bushy Pondwoed Nofal spp. Water - S t a r g r a s s H e t e r o n t h e r o B l a d d e r w o r t U t r l c u l a r l o spp.

STEREOTYPIC PROFILE OF LAKE CHAMPLAIN WETLANDS

CHARACTERISTIC VEOETATION (NOT DRAWN TO SCALE) AT DIFFERENT ELEVATIONS RELATIVE TO LAKE LEVELS

Ft. 105

- EXTREME HIGH

I00

MEAN - HlOH -1

W > W J

- MEAN

. LOW

- EXTREME LOW

C A N A D A

N E W Y O R K

I MISSISQUOI .R. BOUNDARY OF

15 SOUTH HERO


19 SANDBAR REFUGE KILOMETRES 10

22 STEVEN'S BR. -

26 O T T E R CR.

3 1 CHAMPLAIN NARROWS

33 KINGS BAY

34 MONTY BAY

36 SCOMOTION

3 7 A U S A B L E P T . STUDY AREA

43 B L E U R Y ST. , - . . .

4 5 P IKE R.

Transect l i n e s were chosen f o r d e t a i l e d s tudy f rom a e r i a l photographs, topograph ic maps and reconnaissance f i e l d t r i p s f o l l o w i n g t h e s e l e c t i o n of s tudy s i t e s . The t r a n s e c t l o c a t i o n s were g e n e r a l l y s e l e c t e d t o i n t e r s e c t a v a r i e t y o f e l e v a t i o n s and a d i v e r s i t y o f p l a n t species. Data recorded a long t h e t r a n s e c t l i n e s were: species present , numbers present , c o n d i t i o n o f p l a n t s , and water depth. The l a k e e l e v a t i o n and l e n g t h o f t r a n s e c t l i n e s were a l s o recorded each day.

The da ta were entered i n t o a computer f o r s torage and numerous f a c t o r and c o r r e l a - t i o n analyses were conducted t o determine t h e r e l a t i o n s h i p between wa te r depth and species abundance/dis'tr i bu t i on . For each t ransec t , a l l data, i n c l u d i n g a 1 i s t o f species present , t h e i r abundance, depth and d i s t r i b u t i o n were expressed i n g raph ic form ( F i g . 9 ) . These data were analyzed t o p rov ide i n f o r m a t i o n accord ing to : 1 ) phy logene t i c order, 2 ) o rde r of frequency o f occurrence, 3) order o f abundance and 4) descending o r ascending o rde r o f e l e v a t i o n range.


' B o t h s tudy groups r e p o r t e d t h a t s i g n i f i c a n t changes i n the l ake and r i v e r vege ta t i on had occur red i n recen t years because of pro longed per iods o f h i g h water s i n c e 1968. These e f f e c t s were more pronounced i n areas o f low g rad ien t .

The changes were n o t a t t r i b u t e d t o h i g h e r s p r i n g peaks b u t t o prolonged h i g h water l e v e l s d u r i n g t h e growing season ( F i g . 10) . The swamp f o r e s t zone and wet meadow zone t h a t had evo lved d u r i n g years o f normal l a k e l e v e l s (pre-1969) have been invaded by emergent zone species such as common b ladderwor t and broad- leaved arrow l e a f . Dense stands o,f broad- leaved c a t t a i l have developed i n open spaces i n the f o r e s t zone and the normal aqua t i c zone o f emergent and submergent p l a n t s has exper ienced a s h i f t landward.

The growth r a t e o f t he t rees t h a t compose the swamp f o r e s t has been r e t a r d e d by t h e unusua l l y h i g h l a t e s p r i n g and summer water l e v e l s . I n the upper R i c h e l i e u R i v e r area t h e r e has been a steady decrease i n the growth r i n g th ickness o f s i l v e r maple s i n c e 1968. Marked changes i n growth have occur red s ince 1973. The hea l t hy swamp f o r e s t which former ly occupied t h e range of e l e v a t i o n s between 95.1 f t (29.0 m) and 98.4 f t (30.0 m) was found t o have shrunk t o a narrower band between 96.8 f t (29.5 m) and 98.4 f t (30.0 m).

The wet meadow zone, on the t e r r e s t r i a l s i d e o f t he swamp f o r e s t , has expanded i n area due t o the extended d u r a t i o n o f s p r i n g f l oods . However, a long t h e l a k e margin i t has been reduced because o f h i g h e r water l e v e l s d u r i n g the growing season.

I n summary, t he t e r r e s t r i a l vege ta t i on a t e l e v a t i o n s below 97.0 ft (29.6 m) over a t l e d s t t he p a s t e i g h t years was s t ressed o r d i e d - o f f and was rep laced o r invaded by aqua t i c p l a n t s .

, 4.2.4 P r e d i c t e d e f f e c t s

The r e d u c t i o n o f s p r i n g l ake l e v e l s wi 11 have l i t t l e e f f e c t on t h e wet land vege- t a t i o n unless the r e g u l a t i o n o f peak s p r i n g f l oods i s ex t remely severe, i . e . i f peaks o f 98.5 f t (30.0 m ) o r more a re no l onger a1 lowed ' t o occur. Tab le 4 shows t h e expected changes i n vege ta t i ve zones i f peak s p r i n g l a k e l e v e l s a re r e g u l a t e d t o f o u r l e v e l s between 101.7 ft (31.0 m) and 96.8 f t (29.5 m).

Nore impor tan t t o t h e s u r v i v a l , ex ten t , and maintenance o f t h e wet land zones o f vege ta t i on are the l e v e l s t h a t t h e l ake and r i v e r w i l l exper ience i n t h e l a t e s p r i n g and summer. I f c o n d i t i o n s remain s i m i l a r t o those o f t h e p e r i o d 1969 t o 1976, i t i s probab le t h a t the i n v a s i o n o f aqua t i c p l a n t s i n t o zones fo rmer l y occupied by t r a n s i t i o n a l o r t e r - r e s t r i a1 species wi 11 cont inue. Even tua l l y , t h e zonat ion o f s h o r e l i n e vegeta t ion , as recorded p r i o r t o 1969 wi 11 be l o c a t e d a t an e l e v a t i o n somewhat h i g h e r than t h a t recorded i n the e a r l i e r per iod. The r e l a t i v e q u a l i t y and q u a n t i t y o f t he species t h a t w i l l make up the new wet land communities i s unknown. Other f a c t o r s such as exposure t o winds, new c u r r e n t pa t te rns , and s u b s t r a t e composi ti on wi 11 i n f l u e n c e successional changes and t h e es tab l ishn ient o f d i f f e r e n t species. Land use p r a c t i c e s w i l l a l s o be a major f a c t o r i n de- t e r m i n i n g the q u a l i t y and q u a n t i t y o f f u t u r e wet lands. I t i s reasonable t o p r e d i c t t h a t t he more obvious species (maples) c u r r e n t l y under the s t r e s s o f an e leva ted water t a b l e w i l l d ie-back a t l e a s t t o e l e v a t i o n 96.8 ft (29.5 m).

EQUISETUM FLUVIATILE

TYPHA LATlFOLlA

SPIRAEA LATlFOLlA

ACORUS CALAMUS

SAGlTTARlA LATlFOLlA

SlUM SUAVE

POTENTILLA PALUSTRIS

SALlX NlGRA h) cn

MYRICA GALE

SPARGANIUM ANDROCLADUM

ALISMA TRlVlALE

ZlZANlA AOUATICA

POLYGONUM AMPHlBlUM

LEMNA MINOR

F I G U R E 9

AQUATIC PLANT DISTRIBUTION Related to depth of water olong o tronsect located in the west po r t o f P i ke River

Degree o f Abundance-dominance 1 - 2 -3 1 4 H 5

900 FEET

125 METRES

- L a k e S u r f a c e 7 - f 29 1 95.4 X a t

94.8 a z 0 o m 94.2 a

> w 128.5 Lake ~ o t t o m b 93.6 w 3 2

-I I ,28 3

w I- 93.0 ;

I- h. 28.1 - L A K E B O T T O M PROFILE 924 -

F I G U R E 10

STEROTYPIC COMPARISON OF VEGETATIVE CONDITIONS

IN A NORMAL AND ABNORMAL YEAR

I I

I

I 1

I AQUATIC ZONE I TERRESTRIAL ZONE I

A/Situotion In the month of July for a normal year. Spring flooding with gradual fal l to a level around 95 feet (29 metres) in the month of July.

AQUATIC ZONE f TERRESTRIAL ZONE

B/Situation in the month of July for on abnormal year. Spring flooding with part iol fall to ievrl of 97 feet (29.6 metres) in the month of July. ,

TABLE 4

CHANGE IN WETLAND VEGETATION AT VARIOUS LAKE LEVELS

MAXIMUM LAKE LEVEL WETLAND AREA(S) NATURE OF MAGNITUDE Mid-Apr i 1 - Mid-June AFFECTED AND CHANGE IN VEGETATION OF CHANGE

N Co

101.7 f t (31 .0 m)

100.0 f t (30.5 m)

98.5 f t (30.0 m)

96.8 ft (29.5 m)

Grass and Sedge No a p p r e c i a b l e change Meadow -

Grass and Sedge S l i g h t 1 oss Meadow -

Grass and Sedge T o t a l l o s s Meadow -

Swamp Fo res t - Moderate 1 oss

Grass and Sedge T o t a l l o s s Meadow -

Swamp Fo res t - Major l o s s

Emergent Zone - Minor l o s s

l o n e

19i.nor

- Moderate

Major

I f l a t e s p r i n g and summer l e v e l s a re seve re l y reduced, i .e. below 95.5 f t (29.1 m) by mid-Ju ly , t h e reverse s i t u a t i o n may occur and i t t o o i s dependent on o t h e r f a c t o r s as w e l l as l a k e l e v e l s . The most s i g n i f i c a n t change t h a t cou ld occur w i t h lower l a t e s p r i n g and summer l a k e l e v e l s i s w i t h i n t h e sha l low bays, e.g. M iss i squo i Bay. Submergent p l a n t s , such as American tape grass, Canada water weed and t h e i n t roduced species, Euras ian m i l f o i l , may expand i n t o t h e areas fo rmer l y too deep f o r t h e i r ex is tence, produc ing a nuisance e f f e c t on b o a t i n g and swimming.

The present wet meadow zone may become d r y meadow and p rov ide c o n d i t i o n s s u i t a b l e f o r t h e i n v a s i o n o f up land shrubs and t r e e s . Th i s zone, because o f i t s e a r l y v u l n e r a b i l i t y t o changes i n the process of succession, may be the f i r s t and most r a p i d l y a l t e r e d . Q u i t e l i k e l y , intensive farming o f the former wet meadow areas w i l l occur.

4 .2 .5 Targets f o r a v e g e t a t i v e ecosystem

1. P e r i o d i c s p r i n g f l o o d i n g of t h e swamp f o r e s t and wet meadow zone i s r e q u i r e d t o p rov ide t h e necessary mo is t seedbed f o r t h e pe rpe tua t i on o f t h e zones. Th is shou ld occur i f the t a r g e t s suggested by t h e F i s h e r i e s Stud ies a r e achieved.

2. Lake l e v e l s should be lower than 96.8 ft (29.5 m) by mid-June t o a l l o w seasonal regenera t i on w i t h i n t h e wet lands.

3. By mid-Ju ly , t h e l a k e l e v e l should be no lower than 95.5 ft. It should then con t i nue t o f a l l g r a d u a l l y t o n o t lower than 94.0 ft (28.7 m) by November 1.

4.3 Waterfowl


Lake Champlain and t h e upper R i c h e l i e u R i v e r support , throughout t h e year , good popu la t ions o f m i g r a t o r y and r e s i d e n t b i r d s . The water fowl popu la t i on i s t h e most i n t e r - e s t i n g group t o r e s i d e n t s and v i s i t o r s o f t h e area because o f t h e i r r e l a t i v e l y h i g h seasonal ( s p r i n g and fa1 1 ) abundance. A1 though waterfowl a r e recognized as impor tan t game b i r d s , t h e i r concen t ra t i ons and ease of v iewing make them almost e q u a l l y impor tan t as an a t t r a c t i o n f o r p ro fess iona l and amateur n a t u r a l i s t s . The l a k e and r i v e r wet lands o f f e r many opportu- n i t i e s f o r hunters and n a t u r a l i s t s t o use and en joy t h i s resource.

The water fowl species composi t ion t h a t can be seen on t h e l a k e and r i v e r v a r i e s from season t o season and y e a r t o year . The l a r g e r concen t ra t i ons are those o f Canada geese and scaup; t h e former d u r i n g s p r i n g m i g r a t i o n when i c e bound condi ti ons t o t h e n o r t h de lay t h e i r n o r t h e r n m i g r a t i o n and t h e l a t t e r bo th s p r i n g and f a l l when t h e i n v e r t e b r a t e popu la t i ons assoc ia ted w i t h t h e ex tens i ve mats o f f l o a t i n g submergqnt vege ta t i on serve as a major source o f food. I n t h e s p r i n g m ig ra t i on , i t i s n o t uncommon t o observe 100,000 o r rriore water fowl us ing t h e l a k e and upper r i v e r on a g i ven day. Black ducks, ma l l a rds , p i n t a i l s , green-winged t e a l and wood ducks make up t h e m a j o r i t y o f e a r l y "dabb lers" w h i l e scaup, canvasbacks, r ing-necked ducks and mergansers a re t h e m a j o r i t y o f " d i v e r s " . Blue-winged t e a l appear i n good numbers l a t e r .

Dur ing f a l l m i g r a t i o n t h e dabb l i ng ducks, p a r t i c u l a r l y b lack ducks, wood ducks, and ma l l a rds , a re most abundant i n t h e l a t t e r p a r t of September b u t l a t e f l i g h t s o f b l a c k ducks r e g u l a r l y appear i n e a r l y November. D i v i n g ducks, t y p i c a l l y common goldeneye and scaup, a r r i v e somewhat l a t e r w i t h major bu i ld-ups o c c u r r i n g i n e a r l y November and l a s t i n g u n t i l f reeze-up.

Dur ing t h e 1976 hun t ing season, t h e U.S. F i s h and W i l d l i f e Se rv i ce es t imated t h a t t h e t o t a l water fowl ha rves t f o r Lake Champlain i n t h e s t a t e s o f New York and Vermont was about 48,000 b i r d s ( b l a c k ducks and ma1 l a r d s made up about 48% o f t h i s t o t a l ) .

The l a k e and r i v e r wet lands a l s o p rov ide an abundance o f food and cover f o r many m i g r a t i n g and r e s i d e n t non-game b i r d species. They produce an unaccountable expendi ture o f money by r e s i d e n t and v i s i t i n g photographers, a r t i s t s and n a t u r a l i s t s . Al though t h e i r va lue t o t h e a r e a ' s economy i s n o t f u l l y known, i t i s recogn ized by t h e resource managers of t h e area t h a t t h e i r c o n t r i b u t i o n i s cons iderab le and growing.

4.3.2 Methodology . .- :. : , . r-

liine areas were selected f o r study in Vermont and New York S ta tes (Fig. 11) . Field work in the selected areas included the co l lec t ion of information on migration, nest ing, brood production and waterfowl harvest. Considerable information, on a broader s ca l e , was ava i lab le from s t a t e and federal f i l e s and was used t o develop a complete understanding of the a r e a ' s waterfowl productive capabi l i ty and use. Data on spring and f a l l migration were col lected by ground and ae r i a l surveys and re la ted t o the nine study areas . Flock observations were categorized according t o the cover types such as : timber, emergents, submergents, f l oa t i ng , upland and open water.

Nesting s tud ies were confined t o those areas t h a t provided over-water nest ing s i t e s such as flooded timber. Surveys were conducted by canoe o r on foo t depending upon the cover condition. An estimated 90% of the potent ial nesting area was examined during the two spring surveys. Data were recorded on 67 nests located in 1976 and 1977, including: species , observat,ion da tes , c lutch s i z e , height of nest above water, water depth below nest and nesting success.

Brood surveys were conducted t o determine the type of cover used as the seasons progressed. Four basic cover types were used: timber, emergent vegetat ion, uplands and open water. All brood observations recorded age c l a s s , number of young, water depth a t s ight ing and dis tance t o shore. Brood behaviour was a l so noted and included feeding, escaping, loaf ing , preening, swiinmi ng and walking.

Hunter e f f o r t and success data were col lected from the nine study areas during the f a l l of 1976 and additional data obtained through a Vermont s t a t e hunter mail survey. Final ly ,- the lake and r i ve r were surveyed from the a i r during the winter of 1977 t o determine the residual population supported by open water.

Observations were made on occurrence of herons, r a i l s and other marsh birds in re la t ion t o hab i t a t types and water l eve ls . Personnel of the University of Vermont and the Vermont I n s t i t u t e of Natural Science and members of local chapters of the National Audubon Society supplied data on non-game b i rds .

4 . 3 .3 Existing conditions ' During the 1977 spring migration flooded standing timber and emergents were the

preferred habi ta t types used by waterfowl. During t h a t period (March 21 t o May 20) the lake level rose from about 99.1 f t (30.2 m ) t o i t s peak of 100.2 f t (30.5 m ) in e a r ly Apr i l , then f e l l t o 97.9 f t (29.8 m ) by May 20. Waterfowl did not s e l e c t a pa r t i cu l a r water depth t ha t could be re la ted t o any s ing le behaviour pa t te rn .

Four duck species (black ducks, mallard, wood ducks, and blue-winged t e a l ) a r e considered t o be the major breeding waterfowl within the lake and r i ve r . In terms of r e l a t i ve abundance, black ducks contr ibute most t o the loca l ly raised waterfowl population, followed by wood ducks and mallards. However, t h i s can change between areas and years depending on the type of food and cover offered by a pa r t i cu l a r a rea . Nesting data sample s i z e was too small t o determine any difference in species success t h a t could be re la ted t o differences in 1 ake leve ls .

Black ducks and mallards were found nesting only in flooded swamps in 1976. S i t e s selected fo r nesting included t r e e crotches, shelves, stumps, upturned roots and deadfa l l s . None of the 17 nests located (on the average about 4.5 f t above the flood peak) were l o s t t o flooding desp i te the extreme flood of t h a t year. Based on these da t a , high spring water levels had l i t t l e o r no e f f e c t on nesting success.

Brood rear ing success i s re la ted t o the abundance of food and cover during the duckl ing 's ear ly s tages of development. Peak hatching of black ducks and mallards occurred between mid-May and the end of May in 1976 and 1977. In 1976, the lake level on May 15 was 99.2 f t (30.2 m ) while i t was 98.3 f t (30.0 m ) on the same date in 1977. In both years the lake level f e l l almost the same amount (2.8 f t 1 . 9 m) by June 30. Although two sharply d i f f e r en t types of cover conditions resul ted due t o the lower elevat ions of 1977 there was no apparent difference in brood surv iva l .

C A N A D A

N E W Y O R K

I MISSISQUO1 R .


22 STEVEN'S BR.

26 O T T E R C R .

30 E A S T CR.


33 KINGS BAY

37 AUSABLE P T .

Optimum h a b i t a t f o r brood r e a r i n g c o n s i s t s o f swimmable cover, an abundance o f i n v e r - t e b r a t e s as a source o f food, and water l e v e l s t h a t a f f o r d access t o a v a r i e t y o f cover types. Flooded t imber was cons idered of pr ime importance d u r i n g t h e e a r l y l i f e of water fowl broods. Emergents were a l s o ex t remely impor tan t as food and cover f o r broods of a l l ages and any change i n t he e x t e n t o r q u a l i t y of t i m b e r o r emergents would r e s u l t i n impacts on wa te r fow l p roduc t i on .

There was ve ry l i t t l e evidence t h a t f a l l l a k e l e v e l s had any s i g n i f i c a n t e f f e c t on water fowl behav iour a1 though, d u r i n g h i g h wa te r years, water fowl would be more d ispersed. Hunter success was n o t a f f e c t e d by wa te r l e v e l s .

4.3.4 P r e d i c t e d e f f e c t s

The r e l a t i v e abundance of dabb l i ng ducks as m ig ran ts and l o c a l n e s t e r s i s d i r e c t l y i n f l uenced by the area and qua1 i t y o f wet1 and h a b i t a t . A r e d u c t i o n i n , we t l and acreage would r e s u l t i n l e s s waterfowl ' food supp ly and a l o w e r i n g o f t h e c a r r y i n g c a p a c i t y o f t h e wet lands. Other marsh-dependent b i r d s would a l s o be adve rse l y a f f e c t e d .

Sp r i ng and f a l l l a k e l e v e l s w i l l n o t have any s i g n i f i c a n t e f f e c t on t h e m i g r a t i n g popu la t i ons o f water fowl un less ma jo r changes occur i n l a k e l e v e l s and wet lands. P r e f e r r e d h a b i t a t f o r ~ n i g r a t i n g wa te r fow l , as determined by t h e 1976-1977 s t u d i e s , i s f l ooded s t a n d i n g t imber and enlergents. The Vegeta t ion Stud ies i n d i c a t e d t h a t most of t h e swamp f o r e s t zone l i e s a t e l e v a t i o n s between 95. 1 ft (29.0 m) and 98.5 ft (30.0 m). I f s p r i n g l a k e l e v e l s d u r i n g A p r i l and May f a 1 1 w i t h i n t h i s zone waterfowl feedincj and l o a f i n g requ i rements shou ld be met.

Flooded t imber p rov ided t h e b e s t n e s t i n g s i t e s f o r b l a c k ducks and ma l l a rds . B lack ducks i n Lake Champlain b r i n g o f f t h e i r f i r s t c l u t c h e s i n mid t o l a t e May w h i l e m a l l a r d s ha tch o u t i n l a t e May o r e a r l y June. If t h e swamp f o r e s t zone remains inundated u n t i l e a r l y June (as i t no rma l l y has) t hen n e s t i n g success shou ld be s u f f i c i e n t t o m a i n t a i n t h e r e s i d e n t waterfowl popu la t i on .

Only t h e l i v e t r e e s i n t h e f looded swamp f o r e s t zone were s e l e c t e d f o r n e s t i n g s i t e s . The Vegeta t ion Stud ies a l s o i n d i c a t e d t h a t t h e h i g h s p r i n g and summer l a k e l e v e l s s i n c e 1968 have r e s u l t e d i n many o f t he t r e e s between 95. 1 f t (29.0 m) and 96.8 f t (29.5 m) b e i n g s t ressed and i n some areas k i l l e d . If t h e h i g h s p r i n g and summer l e v e l s p e r s i s t , a p o r t i o n o f t h e l a k e s i d e f r i n g e o f t h e f o r e s t zone w i l l be l o s t and w i t h i t many p o t e n t i a l n e s t i n g s i t e s .

Brood s u r v i v a l i s dependent upon t h e a v a i l a b i l i t y o f f ood and cove r t h a t , i n t u r n , i s dependent upon t h e q u a l i t y and q u a n t i t y o f t h e swamp f o r e s t and emergent zones. I f t h e s p r i n g peak requirenlents as determined from t h e F i s h e r i e s Stud ies a r e met t h e i n t e g r i t y o f those zones w i l l be main ta ined.

4 .3 .5 Ta rge t f o r a water fowl ecosystem

1 . Res ident waterfowl b reed ing success i s dependent upon t h e maintenance o f t h e swamp f o r e s t and emergent zones. The ecosystem t a r g e t s suggested b y t h e Vege ta t i ve S tud ies shou ld s a t i s f y t h e wa te r fow l needs. L ikewise, ecosystem t a r g e t s suggested by t h e F i s h e r i e s S tud ies shou ld p r o v i d e t h e necessary i n i t i a t i o n , amp1 i tude and d u r a t i o n o f s p r i n g f l o o d s t o ensure adequate h a b i t a t f o r m i g r a n t and n e s t i n g b i r d s .

4.4 Furbearers .


Lake Champlain and the R i c h e l i e u R i v e r p layed an i m p o r t a n t r o l e i n t h e f u r t r a d e o f no r theas te rn Nor th Ameri ca d u r i n g e x p l o r a t i o n and se t t l emen t . Today, t r a p p i n g s t i l l p ro- v ides a n o t i c e a b l e secondary income source f o r many o f t h e a r e a ' s r e s i d e n t s .

Muskrats have c o n s i s t e n t l y been t h e major species harves ted. Du r ing t h e 1976 t o 1977 s tudy p e r i o d t h e i r p e l t s represented almost 97% o f t h e t o t a l h a r v e s t w h i l e d u r i n g a 1949-52 survey they made up 93% o f t h e t o t a l .

I

1

. ? , I , , 32

4.4.2 Method01 ogy

The same n ine s tudy areas examined d u r i n g t h e Waterfowl Stud ies were used i n t h e Furbearer Stud ies ( F i g . 12 ) .

Muskrat popu la t i on d e n s i t i e s were determined through house counts and bank burrow surveys. A e r i a l surveys were conducted on December 1 and 3, 1976 when house c o n s t r u c t i o n was complete and t h e snow-capped houses were e a s i l y observed f rom t h e a i r . Bank burrows were assessed e a r l i e r (October and November) by observers wa lk ing t h e shore1 i n e .

Occupancy r a t e s and w i n t e r s u r v i v a l were determined by sampl ing houses on each s tudy area between January 27 and March 2, 1977. Se lec ted houses were opened w i t h c ross -cu t saws, shovels and bars . I n a d d i t i o n t o reco rd ing f o r each house t h e number o f muksrats found and t h e i r c o n d i t i o n , data were a l s o recorded on t h e house c h a r a c t e r i s t i c s and t h e i r r e l a t i o n s h i p t o e x i s t i n g water l e v e l s . Each s t r u c t u r e a f t e r examinat ion was r e s t o r e d and resea led. Also, i n 1976, a smal l sample of bank burrows was examined. The types o f vege ta t i on used f o r food, cover and house c o n s t r u c t i o n were recorded throughout a l l t h e f i e l d work.


Water l e v e l s , d u r i n g t h e w i n t e r i n g and b reed ing seasons, a r e cons idered one o f t h e major c o n t r o l l i n g f a c t o r s o f muskrat popu la t i ons . House-bu i ld ing begins i n mid-September and i s u s u a l l y completed by l a t e October. Houses a r e b u i l t t o a l l o w f o r a change i n water l e v e l o f 7 o r 8 inches. R i s i n g l a k e l e v e l s a f t e r f reeze-up o f t h e marshes ( e a r l y November) can t h e r e f o r e be c r i t i c a l .

Rapid r i s e s i n l a k e l e v e l d u r i n g t h e l i t t e r - r a i s i n g p e r i o d can a l s o r e s u l t i n h i g h m o r t a l i t y . Al though t h e p e r i o d i c losses o f muskrats a r e o f t e n spec tacu la r they a r e n o t always c a t a s t r o p h i c . Muskrats have a ve ry h i g h breed ing p o t e n t i a l w i t h a s i n g l e a d u l t p a i r p roduc ing t h r e e o r f o u r l i t t e r s a yea r . Each l i t t e r may number s i x o r seven young and p e r i o d i c losses might he lp t o ma in ta in heal t h y popu la t ions.

Dur ing mid-winter thaws muskrats a re fo rced t o leave t h e i r f looded houses and l a r g e numbers d i e i f they cannot f i n d a l t e r n a t i v e sources o f f ood o r s h e l t e r when c o l d weather r e t u r n s . Fa1 l i n q w i n t e r l ake l e v e l s can be e q u a l l y d i f f i c u l t on muskrat popu la t i ons as they a1 low c o l d a i r i n t o the no rma l l y w a t e r - i n s u l a t e d houses r e s u l t i n g i n f rozen food supp l i es , d i e - o f f s and i nc reased p reda t ion .

The h i g h e r than normal use o f bank burrows and t r e e r o o t s t h a t occur red i n ' l 9 7 6 m igh t have been due t o the unusual l a k e l e v e l s and f l u c t u a t i o n s . The est imated f a l l 1976 muskrat popu la t i on (19,500) f o r t h e Lake Champlain wet lands was cons idered c l o s e t o t h e m i n i~~ iun i 1 eve1 .

4.4.4 P red ic ted e f f e c t s

I f w i n t e r l a k e l e v e l s do n o t f l u c t u a t e more than 1.5 f t ( . 5 m) d u r i n g t h e p e r i o d November 1 t o February 28 major d i e - o f f s o f muskrat should n o t occur.

I f l a k e l e v e l s a r e r e g u l a t e d accord ing t o t h e recommendations o f t h e Vegeta t ion Stud ies and t h e l a k e l e v e l s beg inn ing November 1 a re 94.0 f t (28.7 m) o r h igher , t h e food and cover requirements f o r w i n t e r i n g muskrats should be met.

Muskrat popu la t i ons cou ld be managed by l a k e l e v e l . r e g u l a t i o n d u r i n g t h e w i n t e r months.

4.4.5 Targets f o r a f u r b e a r e r ecosystem

1. Lake l e v e l s should n o t f a l l below 94.0 ft (28.7 m) by November 1. 2 . Dur ing November through February t h e l a k e l e v e l r i s e should be l i m i t e d ove r

t h e f o u r months t o a maximum o f 1.5 f t (.5 m) above t h e November 1 l e v e l ; t a r g e t f o r a :5 ft r i s e .

C A N A D A - _ _ - - - -

N E W Y O R K

BOUNDARY O F DRAINAGE B A S I N

I MlSSlSQUOl R.

1 8 MALLETTS CR.

22 STEVEN'S BR.

26 O T T E R CR.

3 0 E A S T CR.


37 AUSABLE R. LOCATION OF FURBEARER

15 SOUTH HERO

4.5 N u t r i e n t s - P r o d u c t i v i t y


The Committee recognized t h a t t h e N u t r i e n t s - P r o d u c t i v i t y Study i n fo rma t ion would be a d e s i r a b l e i n g r e d i e n t o f a balanced environmental study program f o r t h e l a k e and r i v e r . I t was a l s o r e a l i z e d t h a t r e l a t i n g even l o n g te rm N u t r i e n t s - P r o d u c t i v i t y Study data t o a spe- c i f i c f a c t o r such as f l u c t u a t i n g water l e v e l s i s extremely d i f f i c u l t under t h e b e s t s tudy cond i t i ons . Therefore, t h e 1 i m i t e d scope o f t h e s tudy on t h e Munson F l a t s s e c t i o n o f M a l l e t s Creek Marsh would o n l y p rov ide 1 i m i t e d base1 i n e data on t h e n u t r i e n t p r o d u c t i v i t y o f t h e l a k e wet lands. Never the less , t h e data would be a s t a r t f o r a n u t r i e n t s - p r o d u c t i v i t y s e c t i o n o f any l o n g term environmental m o n i t o r i n g program.

4.5.2 Methodology

The Munson F l a t s s e c t i o n o f M a l l e t t s Creek (F ig . 13;. # l a ) was s e l e c t e d f o r t h e N u t r i e n t s - P r o d u c t i v i t y Study. Randomly se lec ted quadrats were e s t a b l i s h e d w i t h i n each p l a n t zone and sampled p e r i o d i c a l l y , t o enumerate t h e b i o t a , determine biomass and assess major n u t r i e n t s . Transect l i n e s were es tab l i shed t o eva lua te seasonal changes i n p l a n t d i s t r i - b u t i o n . Also, a s tudy was made of t h e a v a i l a b i l i t y o f n i t r o g e n and phosphorus n u t r i e n t s i n t h e sediments as a f u n c t i o n o f season, depth and p l a n t cover . Sediment co re samples were c o l l e c t e d be fo re , d u r i n g and a f t e r t h e growing season.


Stud ies conducted i n 1976 and 1977 i n d i c a t e d t h a t changes i n p l a n t t y p e and abundance ' can occur w i t h i n an area i n per iods as s h o r t as one year . Unusua l ly h i g h water l e v e l con-

d i t i o n s i n 1976 d u r i n g t h e impor tan t aqua t i c p l a n t growing p e r i o d favored p roduc t i on o f f l o a t i ng-submergent vege ta t i on . Very 1 ow 1977 water l e v e l s d u r i n g t h e s i m i 1 a r growing p e r i o d favored t h e growth o f rooted-emergent vege ta t i on . Stud ies a l s o found t h a t i n Munson F l a t s , t h e rooted-emergents produced a much g r e a t e r v e g e t a t i v e biomass than phytop lankton (a lgae ) produced.

Float ing-submergent p l a n t zones were found t o produce more i n s e c t s , o r macroinver- t eb ra tes such as isopods and amphipods, than d i d t h e roo ted aqua t i c zones. These i n s e c t types a re an impor tan t p a r t of young f i s h and water fowl d i e t s . As s t a t e d before , a combi- n a t i o n o f cover (rooted-emergent p l a n t s ) and food ( i n s e c t s ) a re an e s s e n t i a l combinat ion f o r good waterfowl p roduc t i on .

A v a i l a b l e n i t r o g e n , phosphorus and p o s s i b l y s i l i c a s u p ~ l i e s were cons idered t o be p o t e n t i a l l i m i t i n g n u t r i e n t f ac to rs i n the growth o f p l a n t l i f e i n t h e s tudy area and t h e r e f o r e l i m i t i n g f a c t o r s i n t h e o v e r a l l p r o d u c t i v i t y o f t h e wet land. S i l i c a was no t . N i t rogen supp l i es were probab ly adequate, b u t i n s u f f i c i e n t phosphorus supp l i es c o u l d l i m i t p r o d u c t i v i t y a t t imes, p a r t i c u l a r l y d u r i n g t h e c r i t i c a l growing pe r iod .

There were severa l sources o f n i t r o g e n and phosphorus. Dur ing t h e s p r i n g and o t h e r per iods o f heavy r u n o f f Munson's F l a t s ' f o u r t r i b u t a r i e s were capable o f supp ly ing about 40"; o f t h e r e q u i r e d phosphorus and 100% o f t h e n i t rogen . However, some o f these n u t r i e n t s were t ranspor ted o u t i n t o t h e open water p a r t o f t h e marsh o r i n t o t h e l a k e and were u n a v a i l a b l e t o t h e near shore and more sha l low areas where p l a n t l i f e i s most abundant.

Marsh sediments a l s o s t o r e d about 9% of t h e phosphorus and 40% o f t h e n i t r o g e n necessary f o r food p l a n t product ion . Dur ing t h e c r i t i c a l growing season, when t r i b u t a r y stream f l ows a re u s u a l l y q u i t e low, t h e n u t r i e n t s i n t h e sediments a r e very impor tan t t o p l a n t p roduc t i on . On the o t h e r hand, n u t r i e n t s s t o r e d i n t h e c l a y s o i l s on t h e edge o f t h e s tudy area (above 97.0 f t / 2 9 . 6 m) and ad jacen t t e r r e s t r i a l lands were n o t a v a i l a b l e t o t h e marsh p l a n t s , f o r c l a y does n o t r e a d i l y a l l o w t h e water c o n t a i n i n g t h e n u t r i e n t s t o move f r e e l y t o o r f rom t h e marsh.

Less than 1% of the phosphorus and 8% of t h e n i t r o g e n r e q u i r e d by t h e s tudy area p l a n t community i s s u p p l i e d by p r e c i p i t a t i o n f a l l i n g d i r e c t l y on t h e marsh.

- - - _ - - - - -

N E W YORK

V E R M O N T

BOUNDARY OF

18 MALLETTS C R .

4.5.4 P red ic ted e f f e c t s

The Vegeta t ive Stud ies have i n d i c a t e d t h e r e would be no o v e r a l l changes i n p l a n t species abundance o r d i s t r i b u t i o n due t o f l u c t u a t i n g water l e v e l s i f t h e Committee's water l e v e l c r i t e r i a a re f o l lowed. The N u t r i e n t s - P r o d u c t i v i t y Study data i n d i c a t e an increase i n rooted-emergent p l a n t s i n p lace o f f loat ing-submerged type p l a n t s i f unusua l l y low water l e v e l s occur d u r i n g the c r i t i c a l growing pe r iod . Such cond i t i ons should n o t be common i f the Comrni t t e e ' s c r i t e r i a a re fo l l owed .

Floating-subrnergent p l a n t zones a re much more impor tan t producers o f macro inver te- b r a t e than rooted-emergent p l a n t zones. Macro inver tebra tes p roduc t i on shou ld be main ta ined a t a h i g h l e v e l which w i l l ensure a good food supp ly f o r young f i s h and water fowl i f t h e Committee's c r i t e r i a a re fo l l owed . S i m i l a r l y , t h e c r i t e r i a shou ld ensure a good growth o f rooted-emergents necessary f o r d e s i r a b l e waterfowl and o t h e r animal cover and s h e l t e r .

The o v e r a l l supply o f phosphorus and n i t r o g e n should remain f a i r l y constant and be prov ided p r i m a r i l y by runof f from upland areas v i a t r i b u t a r y streams t o t h e s tudy area. Changes i n ad jacent upland use cou ld change t h e present l i m i t i n g supp ly o f phosphorus.

?. '

SECTION 5

DISCUSSION . .

I n r e c e n t yea rs t h e ecosystem of t h e l a k e and r i v e r has been s t ressed by urban iza- t i o n and changes i n s h o r e l i n e l a n d use. Management b i o l o g i s t s and members o f t h e p u b l i c a re concerned t h a t t h e l a k e desc r i bed i n t h e 1930 's as "unique i n t h e no r theas te rn p a r t o f No r th America, i f n o t t h e c o n t i n e n t i n terms of d i v e r s i t y and p r o d u c t i v i t y " , may n o t be a b l e t o w i t h s t a n d these s t resses . Therefore, t h e Environmental Impact Committee has pursued 'a cau t i ous approach t o l a k e l e v e l r e g u l a t i o n and any recommendations made express those concerns.

P l a n t and animal species dependent upon wet land h a b i t a t s have been impacted by man through a g r i c u l t u r a l , commercial, r e s i d e n t i a l and o t h e r development a c t i v i t i e s . I t i s ve ry d i f f i c u l t t o argue on an economic b a s i s t h e r e l a t i v e wor th o f a we t l and b u t t hey a r e i r r e - p laceab le . Man has y e t t o develop t h e a b i l i t y t o c r e a t e f u n c t i o n a l wet lands s i n c e they evo l ve ove r a l o n g p e r i o d o f t ime. However, through sound l a n d and resource use p lann ing , the p r o d u c t i v i t y o f e x i s t i n g wet lands can be main ta ined and even enhanced.

The Committee found i t exceed ing ly d i f f i c u l t t o cons ide r o n l y one o f t h e many f a c t o r s t h a t i n f l u e n c e t h e maintenance and s u r v i v a l o f t h e l a k e and r i v e r renewable n a t u r a l resources, namely, l a k e l e v e l s . Other f a c t o r s and problems e x i s t w i t h i n t h e l a k e and r i v e r t h a t a r e a t l e a s t o f equal importance a l t hough n o t as obvious n o r as w e l l understood. Kany a re c l e a r l y i n t e r t w i n e d w i t h l a k e l e v e l s (See Sec t i on 5 .4) . The Committee would t h e r e f o r e have been very remiss i f i t assumed t h a t t h e h e a l t h o f t h e l a k e and r i v e r can be main ta ined th rough l a k e l e v e l r e g u l a t i o n a lone. Accord ing ly , t h e Committee encouraged t h e s tudy

, personnel t o examine a l l p o s s i b l e f a c t o r s t h a t m igh t be s i g n i f i c a n t t o t h e maintenance and s u r v i v a l o f t h e ecosystem and i t s components.

I d e a l l y , no one shou ld be a l l owed t o l i v e on o r develop f o r any purpose t h e f l o o d p l a i n zone because o f t he problems such development w i l l u l t i m a t e l y c rea te . Most o f these problenis c o u l d be avo ided i f a comprehensive development p l a n was prepared and t h e necessary r e g u l a t o r y c o n t r o l s imposed. The Environmental Impact Committee b e l i e v e s t h e l a k e and r i v e r ' s renewable n a t u r a l resources c o u l d be managed through a combinat ion o f l a k e l e v e l r e g u l a t i o n and r e g u l a t e d f l o o d p l a i n use.

5.1 Ecosystem Taroets

The Committee was asked by t h e Board t o p r o v i d e the necessary l a k e l e v e l e l e v a t i o n , f requency and d u r a t i o n t o m a i n t a i n an acceptab le ecosystem w i t h i n the' l a k e and r i v e r . Study personnel were urged by t h e Committee t o p rov ide suggest ions, e a r l y i n t h e s tud ies , t h a t would be o f va lue i n deve lop ing r e g u l a t i o n c r i t e r i a f o r bo th environmental and f l o o d c o n t r o l concerns. The env i ronmenta l c r i t e r i a f o r r e g u l a t i o n have a l ready been noted i n t h e Summary, Concl us ions and Recommendations sec t ion .

The Environmental Impact Committee recogn ized t h a t t h e F i s h e r i e s and Vegeta t ion Stud ies would p r o v i d e most o f t h e b a s i c da ta needed t o i d e n t i f y t h e c r i t e r i a t o m a i n t a i n an acceptab le ecosystem. The s tudy personnel reviewed t h e e x i s t i n g l i t e r a t u r e f o r management recommendations f rom p rev ious s t u d i e s o f s im i 1 a r o r r e l a t e d species, conducted t h e i r own research and reviewed t h e h i s t o r i c a l records o f Lake Champlain l a k e l e v e l s t o develop t h e t a r g e t s .

The 1976 and 1977 s t u d i e s determined t h a t t o m a i n t a i n a v i a b l e ecosystem l a k e l e v e l s d u r i n g t h e s p r i n g must reach 98.5 ft (30.0 m) and s t a y a t o r above t h a t l e v e l f o r 40 days o r more on t h e average o f a t l e a s t once every t h r e e years . To achieve t h a t t a r g e t , peaks must be above 98.5 ft (30.0 m). Regu la t i on shou ld n o t s i g n i f i c a n t l y de lay t h e t i m i n g o f t he peak s i n c e water tempera ture changes a r e a l s o of cons ide rab le importance.

E l e v a t i o n 98.5 f t (30.0 m) has been e s t a b l i s h e d as t h e acceptab le minimum e l e v a t i o n s ince t h e s t u d i e s showed a t t h a t e l e v a t i o n t h e most c r i t i c a l spawning h a b i t a t , t h e wet meadow zone, becomes a v a i l a b l e . That zone i n recen t yea rs has been exposed t o w i d e l y d i f - f e r i n g c o n d i t i o n s o f f l o o d i n g , compared t o t h e e a r l i e r h i s t o r i c a l pe r i od , and has changed as a r e s u l t .

The l a t e s p r i n g and summer t a r g e t s were developed t o ensure t h a t a d e s i r a b l e balance o f emergent and submergent a q u a t i c v e g e t a t i o n would be main ta ined. I f l e v e l s f a l l t o o low t h e r e w i l l be an i n v a s i o n o f submergent p l a n t s i n t o the zone t h a t i s no rma l l y f r e e o f macrophytes and t h e q u a l i t y of b o a t i n g and swimming w i l l d e t e r i o r a t e .

The r e d u c t i o n i n t h e d u r a t i o n o f s p r i n g h i q h wa te r c u r r e n t l y o c c u r r i n g i n t h e swamp f o r e s t w i 11 h e l p ensure i t s h e a l t h y s u r v i v a l . The Committee's c r i t e r i a w i l l p r o t e c t t i e swamp f o r e s t f rom h i g h water damages.

The w i n t e r t a r g e t s were developed t o manage t h e fu rbea re r oopu la t i on , p a r t i c u l a r l y ~ i i usk ra t s . The Co~ i~n i i t t ee recogn izes t h a t d u r i n g t h e w i n t e r stages, i t i s p o s s i b l e t o r e g u l a t e t h e l a k e and r i v e r w i t h i n any d e s i r e d l i m i t o r f requency. Th is , i n e f f e c t , means t h a t w i l d l i f e managers can use l a k e l e v e l r e g u l a t i o n as a means t o manage t h e muskra t popu- l a t i on as necessary.

The Committee recogn izes t h e importance o f l a k e l e v e l c o n t r o l t o m a i n t a i n an acceptab le downr iver ecosystem. R i v e r f lows shou ld be planned c o n s i s t e n t w i t h ecosystem t a r g e t s f o r t h e l a k e and w i t h i n t h e c o n t e x t o f h i s t o r i c h y d r a u l i c da ta f o r t h e l a k e and r i v e r .

5.2 Base l i ne I n f o r m a t i o n and Fu tu re M o n i t o r i n q

Dur ing p l a n n i n g and development o f t he s t u d i e s t h e Committee recogn ized t h e need t o develop a bas i c comprehensive i n v e n t o r y o f known sources o f da ta on t h e l a k e and r i v e r ' s resources . The Committee i s o f t he o p i n i o n t h a t t h e env i ronmenta l s t u d i e s ach ieved t h a t goal and have p rov ided t h e necessary m a t e r i a l t o develop a m o n i t o r i n g program. That i n v e n t o r y has been augmented by t h e Mew England R i v e r Bas in Commission's Leve l B s t u d i e s .

Euras ian m i l f o i l has been i d e n t i f i e d as one o f t h e p o s s i b l e causes o f t h e "seasonal e f f e c t s phenomenon"41 r e p o r t e d by the P h y s i c a l Aspects Committee (PAC Techn ica l Report , Sec t i on 7 ) . Th is p l a n t , b e l i e v e d t o have been i n t r o d u c e d i n t h e 19601s, i s a l s o a s t r o n g con ipe t i t o r and has responded, p a r t i c u l a r l y i n t he en r i ched bays o f t h e l a k e and t o some e x t e n t i n t he r i v e r , t o produce a heavy mat o f undes i rab le p l a n t growth. The Vege ta t i ve Stud ies i n d i c a t e d t h a t d u r i n g low water pe r i ods , t h i s p l a n t c o u l d comple te ly choke o f f sha l l ow bays and s e r i o u s l y a f f e c t t h e i r c a p a b i l i t y t o produce d e s i r a b l e p l a n t and animal l i f e . The same concerns have been i d e n t i f i e d f o r water ches tnu t . These v e g e t a t i v e problems shou ld be o f r e a l concern t o management agencies and shou ld be i n c l u d e d i n any env i ronmenta l m o n i t o r i n g program.

I f s t r u c t u r a l wa te r l e v e l c o n t r o l i s approved f o r t h e l a k e and r i v e r i t w i l l be e s s e n t i a l t o c a r r y o u t i n t e n s i v e m o n i t o r i n g o f key env i ronmenta l components. Wi thout such mon i to r i ng , i t w i 11 be imposs ib le t o eva lua te and r e f i n e t h e water l e v e l r e g u l a t i o n c r i t e r i a proposed by the s t u d i e s . A p r a c t i c a l m o n i t o r i n g program can be developed f rom t h e s t u d i e s and o t h e r da ta a v a i l a b l e f o r t he l a k e and r i v e r .

The Committee b e l i e v e s t h a t a 10-year m o n i t o r i n g program must be a requ i rement o f any approved water l e v e l r e g u l a t i o n scheme. The Committee recommends t h a t d u r i n g 1978, r e s p o n s i b l e s t a t e , p r o v i n c i a l and f e d e r a l agencies develop and implement an env i ronmenta l m o n i t o r i n g program f o r t h e l a k e and r i v e r . -- 4' An upward t r e n d i n g i n low l a k e l e v e l stages and f o r t he lower end of t h e s tage d i scha rge

r a t i n g curve.

The Committee es t imates the necessary m o n i t o r i n g program i n the Un i ted Sta tes and Canada may c o s t $100,000 - $150,,000 f o r a ten-year pe r iod .

. . ,

5.3 M i t i g a t i o n

Several methods of wet1 and management, through dyking, pumping, and damming a r e p r a c t i s e d throughout t h e U n i t e d Sta tes and Canada. I n fac t , p u b l i c l y owned wet lands w i t h i n t h e l ake and r i v e r a re c u r r e n t l y be ing managed by such techniques. The Committee d i d n o t i n v e s t i g a t e , i n d e t a i l , any s p e c i f i c proposal f o r such a form of mi t i g a t i o n a1 though poss i - b i li t i e s were discussed w i t h con t rac to rs d u r i n g workshop meetings.

Concern f o r t h e we1 fare of t h e 1 ake and r i v e r n o r t h e r n p i k e popu la t i ons r e q u i r e s t h a t t h i s species r e c e i v e the h i g h e s t s p o r t f i s h i n g s t a t u s . U n i f o r m i t y i n h a r v e s t o n l y by accepted a n g l i n g methods would h e l p ensure f u l l p u b l i c p r o t e c t i o n d u r i n g spawning runs and thereby conipensate i n p a r t f o r ongoing changes i n bo th area and q u a l i t y o f wet land h a b i t a t .

5 . 4 Other Environmental Concerns

Present and f u t u r e l and use p r a c t i c e s i n t h e Lake Champlain bas in w i l l be a major f a c t o r i n de te rm in ing f u t u r e l ake and r i v e r cond i t i ons . Recent New England R i v e r Bas in C o ~ r ~ ~ l ~ i s s i o n Leve l B s t u d i e s i n d i c a t e t h a t by the yea r 2000, much o f t h e a g r i c u l t u r a l lands ad jacent t o t h e shores o f Lake Champlain w i 11 have been conver ted t o r e c r e a t i o n a l and r e s i - d e n t i a l use. How man uses the f l o o d p l a i n w i 11 determine t o a l a r g e degree what type of f l o o d c o n t r o l systems wi 11 be e f f e c t i v e . How man uses t h e e x i s t i n g wet lands and t h e i r per iphery , as w e l l as adjacent uplands wi 11 be a major f a c t o r i n de te rm in ing t h e f u t u r e q u a l i t y and q u a n t i t y o f l ake and r i v e r wet land areas. This, i n t u rn , w i l l determine the w e l l be ing o f assoc ia ted f i s h and w i l d l i f e resources, a l l o f which w i l l have d i r e c t bea r ing on the economic w e l f a r e o f the l ake and r i v e r communities dependent on expendi tures o f hunters , f ishermen and n a t u r a l i s t s .

The Conunittee's r e c o g n i t i o n of t he need f o r l and use r e g u l a t i o n would n o t be prec- edent s e t t i n g . S t a t e l e g i s l a t i on,5/ f o r example, has a l ready p laced major l e g a l r e s t r i c t i o n s on l and uses t h a t may be de t r imen ta l t o wet lands.

Water q u a l i t y has been i d e n t i f i e d as a major source o f concern i n t h e New England R i v e r Bas in Commission's P lann ing Guide (1976) and severa l i ssues have been descr ibed. Dur ing the C o m i t t e e ' s s tud ies , severa l s i t u a t i o n s were noted where the e u t r o p h i c a t i o n process had obv i ous l y been acce le ra ted through t h e i nc reased d ischarge o f domes ti c and/or i n d u s t r i a l waste. Study personnel i n d i c a t e d t h a t t h e e f f e c t s o f t h i s enr ichment and t h e spread o f e x o t i c p l a n t forms cou ld s i g n i f i c a n t l y a l t e r t he q u a l i t y o f many p a r t s o f t h e l a k e and r i v e r i f remedial measures are n o t i n s t i t u t e d .

The s i g n i f i c a n c e of t he "seasonal e f f e c t s phenomenon" i s o f p a r t i c u l a r concern t o t h e Environmental Impact Committee as i t r a i s e s the ques t i on as t o whether i t i s permanent o r temporary. The Vegeta t ion Stud ies have shown t h a t i n recen t years the e leva ted l a k e and r i v e r l e v e l s d u r i n g the growing p e r i o d have had s i n g i f i c a n t e f f e c t s on t h e succession process. They have demonstrated t h a t t h e swamp f o r e s t has been under cons iderab le s t r e s s due t o pro longed inunda t ion and i n some areas t h e r e has been a l o s s o f a p o r t i o n o f t h i s zone. I f the t r e n d cont inues o r if t h e lake l e v e l s d u r i n g t h e growing season remain as they are then the lake-zones can a l s o be expected.

I t can be concluded from the i n f o r m a t i o n gained f rom t h e s t u d i e s o f t h e Board 's t h r e e commi t t e e s t h a t water l e v e l r e g u l a t i o n admin is tered by i n t e r n a t i o n a l r e p r e s e n t a t i o n cou ld be b e n e f i c i a l t o the l ake and r i v e r ' s n a t u r a l resources. To be most b e n e f i c i a l reg- u l a t i o n shou ld be combined w i t h sound l a n d use p r a c t i c e s and o t h e r s o c i o l o g i c a l concerns f o r

5 / New York S ta te Freshwater Wetlands Act 1975

those areas a f f e c t e d by the l ake and r i v e r . Any water l e v e l r e g u l a t i o n must be coupled w i t h an environmental m o n i t o r i n g program t h a t w i l l p rov ide the necessary i n f o r m a t i o n t o develop the bes t long- term llianagement o f t h e l a k e ' s and r i v e r ' s resources.

, ' ,. ,....! - . - . . I . . 1 . ,

. . ..&*. : ' ?'A '; , , " . , . . .

, ..

Anon. 1930. A b i o l o g i c a l survey of t h e Lake Champlain watershed. Supplement t o t h e N ine teen th Annual Report , 1929, of t h e Conservat ion Dept. Albany.

Anon. 1976. Lake Champlain p l a n n i n g gu ide f o r water and r e l a t e d l a n d resources. New England R i v e r Bas in Commission, 122 p.

G i l b e r t , A.H. 1977. Report t o t h e Environmental Impact Committee o f t h e Lake Champlain-Richel ieu Board on t h e va lue o f h u n t i n g and f i s h i n g on Lake Champlain, unpub. 11 p.

G i l l e s p i e , D . I . 1976. Lake Champlain l a k e l e v e l s , a work ing r e p o r t , No. 2, unpub. 78 p.

Hanlon, L.C. 1963. H i s t o r i c a l survey o f Lake Champlain 's F i she ry , unpub. 93 p.

Thompson, 3. 1842. H i s t o r y o f Vermont, Na tu ra l , C i v i l , and S t a t i s t i c a l . P a r t F i r s t , Na tu ra l H i s t o r y o f Vermont, Chauncey Goodr ich B u r l i n g t o n , V t . pages 1 - 224.

-

6' The Suppor t ing Data Reports p rov ide d e t a i l e d re fe rence m a t e r i a 1 f o r each s tudy .

APPENDIX A

DIRECTIVE TO ENVIRONMENTAL IMPACT COMMITTEE

The I n t e r n a t i o n a l Champlain-Richel i e u Board (ICRB) was e s t a b l i s h e d on May 5, 1975, by t h e I n t e r n a t i o n a l J o i n t Commission ( IJC) t o undertake, through a p p r o p r i a t e agencies i n Canada and t h e Un i ted Sta tes , t h e necessary i n v e s t i g a t i o n s and s tud ies and t o adv i se t h e IJC on a l l mat ters which i t must cons ider i n comple t ing i t s r e p o r t t o governments under t h e re fe rence dated March 29, 1973, on the r e g u l a t i o n o f Lake Champlain and R i chel i eu R ive r .

Pursuant t o t h e I J C ' s d i r e c t i v e t o t h e ICRB, dated June 11, 1975, t h e ICRB e s t a b l i s h e d J u l y 11, 1975, the Environmental Impact Committee.

I h e Committee s h a l l adv ise t h e ICRB as t o a p l a n o f s tudy t o eva luate :

(a ) The area o f t h e wet lands t o be a f f e c t e d by t h e proposed r e g u l a t i o n schemes. ( b ) The a n t i c i p a t e d e f f e c t s o f proposed r e g u l a t i o n schemes on t h e type o f p l a n t and

animal assoc ia t i ons e x i s t i n g i n t h e wet lands determined by ( a ) . ( c ) The economic importance o f t h e wet lands and t h e i r i n h e r e n t values and t h e e f f e c t s

o f proposed r e g u l a t i o n schemes on t h i s economic base. ( d ) The importance o f wet lands i n f i l t e r i n g n u t r i e n t s and s i l t f r om t r i b u t a r y streams

d u r i n g s p r i n g r u n o f f pe r iods and t h e a n t i c i p a t e d e f f e c t s o f proposed r e g u l a t i o n schemes on t h i s process.

( e ) The p o s s i b i l i t i e s o f enhancing by water l e v e l r e g u l a t i o n t h e wet land resource base and i t s economic va lue.

( f ) Measures t o m i t i g a t e nega t i ve environmental impacts r e s u l t i n g f rom f l o o d c o n t r o l . ( g ) Any o t h e r mat ters as may war ran t c o n s i d e r a t i o n i n t h e judgment o f t h e Committee.

The Comnii t t e e s h a l l preps.re and submit f o r ICRB approval , by August 15, 1975, and s u b j e c t t o c o n s t r a i n t s i n funding as i n d i c a t e d i n t h e a t tached appendix, an o u t l i n e o f t he program o f i n v e s t i g a t i o n s and s tud ies t h a t i t recommends, a schedule o f t h e es t imated t ime and costs i n v o l v e d i n t h e comple t ion o f each o f t h e severa l phases, a l i s t o f t he apencies proposed t o c a r r y them o u t .

The Comniittee w i l l c o n s i s t o f a Un i ted S ta tes Sec t i on and a Canadian Sect ion, each hav ing f o u r members.

Members o f t h e Committee, whether o r n o t employed by departments o r agencies o f gov- ernment, a re n o t rep resen ta t i ves o f t h e i r employers. They serve i n a personal and p ro fess iona l capac i t y under t h e d i r e c t i o n o f t h e ICRB, and t h e i r employers and supe- r i o r s are n o t committed i n any way by t h e ac t i ons o f t h e i n d i v i d u a l member o r t h e Commi t tee.

The ICRB w i l l p rov ide f u r t h e r i n s t r u c t i o n t o t h e Environmental Impact Committee upon t h e submission o f t h e recommended work p lan.

I n c a r r y i n g o u t i t s funct ions under t h i s d i r e c t i v e , t h e Committee w i l l a c t as an u n i t a r y body, c a r r y i n g o u t i t s i n v e s t i g a t i o n s j o i n t l y i n b o t h c o u n t r i e s as a co-ord inated and i n t e g r a t e d e f f o r t .

The Committee s h a l l n o t re lease i n fo rma t ion gathered i n t h e conduct o f i t s i n v e s t i g a - t i o n s o r programs f o r which i t i s respons ib le u n t i l such i n f o r m a t i o n has been presented t o t h e ICRB and a p p r o p r i a t e a u t h o r i z a t i o n has been g ran ted by the ICRB. The Committee s h a l l observe the P u b l i c Re la t i ons P o l i c y o f t h e ICRB.

APPENDIX B

SUPPORTING DATA REPORTS

F i s h e r i e s

Dumont P. and R. F o r t i n 1977. E f f e c t s o f s p r i n g water l e v e l s on t h e rep roduc t i on o f upper R i c h e l i e u and Miss isquo i Bay n o r t h e r n p i k e (Esox l u c i u s L.). U n i v e r s i t y o f Quebec a t Montreal .

K re tse r , Wai ter , A. 1977. F i s h e r i e s i n v e s t i g a t i o n s f o r t h e r e p o r t s t o t h e I n t e r n a t i o n a l d o i n t Commission on t h e r e g u l a t i o n of Lake Champlain. New York S t a t e Department o f Envi ronmental Conservat i on and Vermont Agency o f Envi ronmental Conservat ion.

Vegeta t ion

Countryman, Wi l l iam, 0. 1977. An a n a l y s i s o f l ake l e v e l i n f l u e n c e on vege ta t i on . Aquatec Inc . , South B u r l i n g t o n , Vermont.

Hamel, C . and P. Bhereur, 1977. I n f l uences o f s p r i n g water l e v e l s on aqua t i c and r i p a r i a n p l a n t d i s t r i b u t i o n i n upper R i c h e l i e u and Miss isquo i Bay areas. Un ive rs i t y o f Quebec a t Montreal .

water fowl - Furbearers

Myers, T. R . and D. D. Foley, 1977. A r e p o r t t o the I n t e r n a t i o n a l Champlain-Richel i e u Board on the p r o d u c t i v i t y o f Lake Champlain w i t h rega rd t o water fowl , f u rbea re rs and o t h e r wi l d l i f e . S ta te o f Vermont Agency o f Environmental Conservat ion, Department o f F ish and Game.

N u t r i e n t s - P r o d u c t i v i t y

Henson, E.B. and M. Potash, 1977. B i o l o g i c a l p roduc t i on and n u t r i e n t s t u d i e s f o r t h e r e p o r t s t o the I n t e r n a t i o n a l J o i n t Commission on the r e g u l a t i o n o f Lake Champlain. U n i v e r s i t y o f Vermont.

Turk, John,T. 1977. Apparent use o f sediment n i t r o g e n and phosphorus by p l a n t s i n M a l l e t t s Creek Marsh wi t h i m p l i c a t i o n s t o l a k e l e v e l r e g u l a t i o n . U.S. Geological Survey. !

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