the fish assemblage structure of the saco river estuary

BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofit publishers,academic institutions, research libraries, and research funders in the common goal of maximizing access to critical research.

The Fish Assemblage Structure of the Saco River EstuaryAuthor(s): Nathan B. Furey and James A. SulikowskiSource: Northeastern Naturalist, 18(1):37-44. 2011.Published By: Eagle Hill InstituteDOI: http://dx.doi.org/10.1656/045.018.0104URL: http://www.bioone.org/doi/full/10.1656/045.018.0104

BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in thebiological, ecological, and environmental sciences. BioOne provides a sustainable onlineplatform for over 170 journals and books published by nonprofit societies, associations,museums, institutions, and presses.

Your use of this PDF, the BioOne Web site, and all posted and associated content indicatesyour acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use.

Usage of BioOne content is strictly limited to personal, educational, and non-commercialuse. Commercial inquiries or rights and permissions requests should be directed to theindividual publisher as copyright holder.

http://dx.doi.org/10.1656/045.018.0104

http://www.bioone.org/doi/full/10.1656/045.018.0104

http://www.bioone.org

http://www.bioone.org/page/terms_of_use

NORTHEASTERN NATURALIST2011 18(1):37–44

The Fish Assemblage Structure of the Saco River Estuary

Nathan B. Furey1,2,* and James A. Sulikowski1

Abstract - The Saco River estuary is a narrow estuary in southern Maine, for which the fauna has not been described in nearly 30 years. Beach seining, otter trawling, and beam trawling were conducted between April and October of 2007 and 2008 to assess seasonal variation in fi sh assemblage structure. Twenty-four species were observed over the two sampling seasons, and nearly all species were at lengths indicative of juvenile age. Clu-pea harengus (Atlantic Herring), Pseudopleuronectes americanus (Winter Flounder), Anguilla rostrata (American Eel), Microgadus tomcod (Atlantic Tomcod), Pomatomus saltatrix (Bluefi sh), and Osmerus mordax (Rainbow Smelt) are either commercially or recreationally valuable, while Acipenser oxyrynchus oxyrynchus (Atlantic Sturgeon), Alosa aestivalis (Blueback Herring), and Rainbow Smelt are federally listed species of concern. Substantial historical assemblage changes were observed, including both the loss of commercially important species and the addition of species of concern. Regular monitoring of estuarine habitats is necessary to identify changes in assemblages and to better understand potential drivers of ecosystem change.

Introduction

The Saco River estuary is a small estuarine environment in Biddeford, ME. To our knowledge, only one published study (Reynolds and Casterlin 1985) has described the nekton of the Saco River estuary. Reynolds and Casterlin (1985) sampled the entire extent of the Saco River and its surrounding coastal waters with otter trawl, seine, bottom grab, hook and line, plankton net, and hand net, and although effort was not quantified, the authors noted that sam-pling occurred throughout all seasons of the years of 1979 to 1982. While more recent studies have examined Saco River geology and hydrography (Brothers et al. 2008, FitzGerald et al. 2002, Kelley et al. 2005), the estuary’s flora and fauna have not been described in nearly 30 years. The present study aimed to describe the fish assemblage of the Saco River estuary over a two-year period (20 April 2007 to 2 December 2008) to determine nursery ground potential and identify possible assemblage changes since the previous study (Reynolds and Casterlin 1985).

Methods

Field-site description Sampling occurred in the Saco estuary at the mouth of the Saco River (43°27.5'N, 70°22'W) (Fig. 1). Two jetties extend 1.5 km into Saco Bay to form

1Marine Sciences Department, University of New England, 11 Hills Beach Road, Bidde-ford, ME 04005. 2Current address - Department and Wildlife and Fisheries Science, Texas A and M University- Galveston, 5007 Avenue U, Galveston, TX 77551. *Corresponding author - [email protected].

Northeastern Naturalist Vol. 18, No. 138

the Saco River mouth. Sampling occurred between the jetties as well as on a shallow, sandy portion of the estuary known as Freddy Beach (Fig. 1). The estu-ary ranges between 200 and 350 m in width and is characterized by sand and rock bottoms, and little vegetation. The Saco River has a discharge rate of greater than 85 m3/s (USGS 2009). Under normal conditions, the estuary’s salinity is stratifi ed by salt wedge presence, and experiences a mean tidal range of 2.7 m (FitzGerald et al. 2002). Sampling sites were chosen to ensure that estuarine water was being sampled, rather than pure fresh- or saltwater.

Sampling gear A 2-mm square mesh beach seine, 14 m long and 2 m high, was used to sample Freddy Beach (Fig. 1). Three replicate seines, approximately 100 m in length, were performed between low and mid-tide weekly in 2007 and twice weekly in 2008. A small otter trawl (6 m wide and 25-mm mesh) and beam trawl (2 m wide and 3-mm mesh) were towed between the jetties on a bi-monthly basis in 2007 and weekly in 2008 from the 7-m (23-ft) University of New England research vessel Llyr. The use of trawls allowed for the sampling of waters deeper than those attainable by seine, and the beam trawl was used to sample areas close to the jetties rather than the deeper channel. The current study focused on the estuarine portion of the river, coinciding with Stations 4 and 5 of Reynolds and Casterlin (1985).

Data collection Sampling began in April 2007 and ended in October 2008. In both 2007 and 2008, sampling occurred from April through October. All captured fi sh were identifi ed to species and enumerated. For every sampling event where at least 100

Figure 1. Location of the Saco River estuary system in eastern Biddeford, ME. Star denotes Freddy Beach where beach seines occurred. Trawls occurred between jetties as outlined by rectangle.

N.B. Furey and J.A. Sulikowski2011 39

fi sh of a species were captured, a subsample of 50 individuals was measured for total length (TL). To approximate the age of observed species as either juvenile or adult, mean lengths of fi sh species were compared to average adult and juvenile sizes found in literature specifi c to the Gulf of Maine. To assess potential changes in the fi sh assemblage, the presence of each species was compared to those ob-served by Reynolds and Casterlin (1985).

Results

Overall Twenty-four fi sh species were observed in the Saco River estuary over the course of the 2-year study (Tables 1, 2), and Alosa aestivalis (Blueback Herring),Menidia menidia (Atlantic Silverside), Clupea harengus (Atlantic Herring), Os-merus mordax (Rainbow Smelt), and Ammodytes americanus (Sand Lance) were the fi ve most dominant species. More species were observed with seine (23) than either beam trawl (8) or otter trawl (9).

Size (TL) Sizes of observed fi sh during the study ranged from a minimum of 8 mm TL (Atlantic Silverside) to a maximum of 1200 mm TL (Acipenser oxyrinchus

Table 1. Full nomenclature of all 24 fi sh species observed in the study.

Common name Scientifi c name Authority Bluefi sh Pomatomus saltatrix L. Largemouth Bass Micropterus salmoides (Lacèpede) Striped Mullet Mugil cephalus L. Red Hake Urophycis chuss (Waldbaum) Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus Mitchill American Eel Anguilla rostrata Laueur Atlantic Herring Clupea harengus L. Alewife Alosa pseudoharengus (Wilson) Cunner Tautogolabrus adspersus (Walbaum) Winter Flounder Pseudopleuronectes americanus Walbaum Yellow Perch Perca fl avescens (Mitchill) Blueback Herring Alosa aestivalis Mitchell Windowpane Scophthalmus aquosus (Mitchill) Pumpkinseed Lepomis gibbosus (L.) Rainbow Smelt Osmerus mordax Mitchell Atlantic Tomcod Microgadus tomcod Walbaum Northern Pipefi sh Syngnathus fuscus Storer Sand Lance Ammodytes americanus Dekay Atlantic Silverside Menidia menidia L Mummichog Fundulus heteroclitus heteroclitus (L.) Threespine Stickleback Gasterosteus aculeatus L. Banded Killifi sh Fundulus diaphanus (Lesueur) Ninespine Stickleback Pungitius pungitius occidentalis Cuvier Fourspine Stickleback Apeltes quadracus Mitchill

Northeastern Naturalist Vol. 18, No. 140 Ta

ble

2. O

vera

ll m

ean

tota

l len

gths

(TL)

and

stan

dard

dev

iatio

ns (S

D) f

or a

ll 24

fi sh

spec

ies o

bser

ved

in th

e st

udy.

Als

o gi

ven

are

aver

age

and

max

imum

adu

lt TL

(or s

tand

ard

leng

th, S

L, w

hen

note

d) c

ited

in s

cien

tifi c

lite

ratu

re fo

r eac

h sp

ecie

s. A

ster

isk

(*) d

enot

es s

ourc

e is

as

cite

d in

Col

lette

and

Kle

in-M

acPh

ee

2002

. An

“X”

in “

Pres

ent”

indi

cate

s th

e sp

ecie

s w

as p

revi

ousl

y ob

serv

ed w

ithin

the

estu

arin

e po

rtion

of

the

river

that

mat

ches

the

curr

ent s

tudy

’s e

xten

t (S

tatio

ns 4

and

5, R

eyno

ds a

nd C

aste

rlin

1985

).

Se

ine

(mm

) O

tter t

raw

l (m

m)

Bea

m tr

awl (

mm

) Li

tera

ture

val

ue (m

m)

Com

mon

nam

e Pr

esen

t M

ean

SD

M

ean

SD

M

ean

SD

A

vera

ge

Max

S

ourc

e*

Blu

efi s

h

66

.21

5.88

11

3 N

A

NA

N

A

NA

11

50

Col

lette

and

Kle

in-M

acPh

ee 2

002

Lar

gem

outh

Bas

s

61.0

0 40

.22

NA

N

A

NA

N

A

NA

97

0 P

age

and

Bur

r 199

1 S

tripe

d M

ulle

t

55.2

7 17

.42

NA

N

A

NA

N

A

NA

60

0 M

cDon

ough

and

Wen

ner 2

003*

Red

Hak

e

75.5

0 10

.29

NA

N

A

NA

N

A

NA

50

0 M

usic

k 19

67*

Atla

ntic

Stu

rgeo

n

NA

N

A

1132

.50

95.4

6 N

A

NA

88

0–20

00

NA

D

amon

-Ran

dall

et a

l. 20

10 A

mer

ican

Eel

X

52

.00

0.82

N

A

NA

85

43

.84

NA

12

00

Big

elow

and

Shr

oede

r 195

3* A

tlant

ic H

errin

g

48

.50

5.74

52

.12

6.96

38

3.

46

NA

43

0 C

olle

tte a

nd K

lein

-Mac

Phee

200

2 A

lew

ife

56

.27

8.26

N

A

NA

46

.63

10.6

5 N

A

300

Ros

s 19

91*

Cun

ner

11

.50

NA

N

A

NA

N

A

NA

15

0–25

0 N

A

Big

elow

and

Shr

oede

r 195

3* W

inte

r Flo

unde

r X

71

.35

55.1

9 13

1.47

52

.12

134.

75

29.4

7 N

A

580

Fie

lds

1988

* Y

ello

w P

erch

25.0

0 N

A

NA

N

A

NA

N

A

NA

40

0 P

age

and

Bur

r 199

1 B

lueb

ack

Her

ring

43.3

8 14

.73

66.1

4 6.

84

NA

N

A

NA

30

0 R

oss

1991

* W

indo

wpa

ne

56

.58

19.3

4 12

3.55

48

.03

NA

N

A

250–

305

NA

B

igel

ow a

nd S

hroe

der 1

953*

Pum

pkin

seed

49.0

0 N

A

NA

N

A

NA

N

A

NA

40

0 P

age

and

Bur

r 199

1* R

ainb

ow S

mel

t

49.6

8 13

.18

49.2

1 6.

45

NA

N

A

180–

230

NA

C

olle

tte a

nd K

lein

-Mac

Phee

200

2 A

tlant

ic T

omco

d

X

41.8

7 9.

49

NA

N

A

33.3

5 21

.57

228–

300

NA

C

olle

tte a

nd K

lein

-Mac

Phee

200

2 N

orth

ern

Pipefi s

h

10

2.64

51

.28

NA

N

A

148.

33

28.0

4 N

A

305

Nic

hols

and

Bre

der 1

927*

San

d La

nce

X

68

.26

27.6

7 60

.00

27.5

5 58

.71

9.48

N

A

168

Niz

insk

i et a

l. 19

90*

Atla

ntic

Silv

ersi

de

68

.56

20.3

0 44

.62

4.44

N

A

NA

10

5 N

A

Con

over

and

Ros

s 19

82*

Mum

mic

hog

46.7

6 13

.11

NA

N

A

NA

N

A

NA

10

0 A

ble

1990

* T

hree

spin

e St

ickl

ebac

k

31

.03

16.4

6 N

A

NA

N

A

NA

40

–70

NA

C

olle

tte a

nd K

lein

-Mac

Phee

200

2 B

ande

d K

illifi

sh

44

.03

8.78

N

A

NA

N

A

NA

15

2–17

8 N

A

Cle

mm

er a

nd S

chw

artz

196

4 N

ines

pine

Stic

kleb

ack

33.2

2 4.

18

NA

N

A

NA

N

A

35–5

5 SL

76

S

cott

and

Scot

t 198

8*;

A

yvaz

ian

and

Kru

eger

199

2* F

ours

pine

Stic

kleb

ack

30.5

0 7.

51

NA

N

A

53.5

0 3.

53

23–4

4 N

A

Blo

uw a

nd H

agen

198

4*


oxyrinchus [Atlantic Sturgeon]). All but three observed fi sh (2 Atlantic Sturgeon and 1 Pseudopleuronectes americanus Walbaum [Winter Flounder]) were less than 250 mm TL. Except one Winter Flounder (TL = 552 mm), all individuals captured with seine were less than 200 mm TL. All fi sh observed by beam trawl were between 16 mm and 166 mm TL, and besides two Atlantic Sturgeon, all fi sh observed by otter trawl were less than 300 mm TL. When compared to literature examining the size of northwest Atlantic fi shes, only 3 species—Gasterosteus aculeatus (Threespine Stickleback), Apeltes quadracus (Fourspine Stickleback), and Pungitius pungitius occidentalis (Ninespine Stickleback)—were not consid-ered to be juvenile (Table 2).

Discussion

Twenty-four fish species were observed in the Saco River estuary over a 2-year period, and nearly all species observed were at juvenile lengths. Atlan-tic Herring, Winter Flounder, Anguilla rostrata (American Eel), Microgadus tomcod (Atlantic Tomcod), Pomatomus saltatrix (Bluefish), and Osmerus mordax (Rainbow Smelt) are either commercially or recreationally valuable. In addition, the Alosa pseudoharengus (Alewife), Atlantic Sturgeon, Blueback Herring, and Rainbow Smelt are federally listed as species of concern (NMFS 2009). Of these economically valuable and threatened species, four (Blueback Herring, Alewife, Winter Flounder, and Rainbow Smelt) were observed over multiple months, indicating that their presence was not an anomaly. All of these species were observed as juveniles, indicating the estuary’s value as a nursery ground. The number of fish species observed within the Saco River estuary (24) is comparable to other Maine estuaries, including Penobscot Bay (22) (Lazzari and Tupper 2002), Wells Harbor (24) (Ayvazian et al. 1992), Kennebec Point (27) (Lazzari et al. 1999), the Weskeag River (22) (Lazzari 2002), and Casco (25) and Muscongus bays (24) (Lazzari 2002). Furthermore, the estuaries of Penobscot Bay, Wells Harbor, Kennebec Point, and Casco Bay are of greater width and volume than the studied Saco River estuary. Only two of these com-pared studies, however, included beach seines as sampling gear (Ayvazian et al. 1992, Lazzari et al. 1999). The other aforementioned studies collected fish via beam trawl, otter trawl, or throw traps. Because the species observed, along with their abundance, can be affected by gear type (Rozas and Minello 1997), comparing species richness among these ecosystems is difficult. Re-gardless, these comparisons describe the Saco River estuary as ecologically valuable to the region despite its relatively modest size. Substantial differences exist between the fi sh assemblage observed by Reyn-olds and Casterlin (1985) and that observed in the current study (Table 2). Of the fi ve most abundant species in the current study, only Sand Lance was observed by Reynolds and Casterlin (1985). An additional six species (Fundulus heteroclitus heteroclitus [Mummichog], Urophycis chuss [Red Hake], Scophthalmus aquosus[Windowpane], Fourspine Stickleback, Threespine Stickleback, and Ninespine


stickleback) were common to both studies, but were only observed by Reynolds and Casterlin (1985) outside of the current study’s sampling area. Notable species that were only observed in the current study include Alewife, Atlantic Sturgeon, Blueback Herring, and Rainbow Smelt, all of which are fed-eral species of concern (NMFS 2009). Both Leucaraja erinacea Mitchill (Little Skate) and Pollachius virens L. (Pollock) were observed by Reynolds and Cast-erlin (1985) within the estuary, but not in the current study. Both of these species are commercially important in the Gulf of Maine. Comparisons to historical data can identify at-risk species (Smith et al. 2008), and regular monitoring will allow for identifi cation of possible drivers of assem-blage change. Continual monitoring of estuarine habitats should be a priority for conservationists and managers alike, given the observed loss of commercially important species, and the apparent additions of at-risk species observed in the Saco River estuary in a period of less than 30 years.

Acknowledgments

We would like to thank Tim Arienti, Marie Quinlan, Angela Cicia, Andrew Wargo, and Devin Flawd for assisting in fi eld work. This project was supported by the University of New England Biological Sciences Honors Program, the University of New England College of Arts and Sciences (CAS), and the University of New England Provost’s Fac-ulty Grant Program. This manuscript represents MSC contribution number 32.

Literature Cited

Able, K. 1990. Life-history patterns of salt marsh killifi shes in New Jersey. Bulletin of the New Jersey Academy of Science 35:23–30.

Ayvazian, S., and W. Krueger. 1992. Lateral plate ontogeny of the North American Nine-spine Stickleback, Pungitius occidentalis. Copeia 1992:209–214.

Ayvazian, S.G., L.A. Deegan, and J.T. Finn. 1992. Comparison of habitat use by estua-rine fi sh assemblages in the Acadian and Virginian zoogeographic provinces. Estuar-ies 15(3):368–383.

Bigelow, H.B., and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. Fisheries Bul-letin, US 53:1–577.

Blouw, D., and D. Hagen. 1984. The adaptive signifi cance of dorsal spine variation in the Fourspine Stickleback, Apeltes quadracus. III. Correlated traits and experimental evidence on predation. Heredity 53:371–382.

Brothers, L., D. Belknap, J. Kelley, and C. Janzen. 2008. Sediment transport and disper-sion in a cool-temperate estuary and embayment, Saco River estuary, Maine, USA. Marine Geology 251:183–194.

Clemmer, G., and F.J. Schwartz. 1964. Age, growth, and weight relationships of the Striped Killifi sh, Fundulus majalis, near Solomons, Maryland. Transactions of the American Fisheries Society 93:197–198.

Collette, B.B., and G. Klein-MacPhee. (Eds). 2002. Bigelow and Schroeder’s Fishes of the Gulf of Maine. 3rd Edition. Smithsonian Institute, Washington, DC. 748 pp.

Conover, D., and M. Ross. 1982. Patterns in seasonal abundance, growth, and biomass of the Atlantic Silverside, Menidia menidia, in a New England estuary. Estuaries 5:275–286.


Damon-Randall K., R. Bohl, S. Bolden, D. Fox, C. Hager, B. Hickson, E. Hilton, J. Mohler, E. Robbins, T. Savoy, and A. Spells. 2010. Atlantic Sturgeon research tech-niques. NOAA Technical Memorandum NMFS NE 214. 19 pp. National Marine Fish-eries Service, Woods Hole, MA.

Fields, B. 1988. Winter Flounder, Pseudopleuroncetes americanus. Pp. 103–104, In J. Penttila and L.M. Dery (Eds.). Age-determination methods for northwest Atlantic species. NOAA Technical Report NMFS No. 72. Woods Hole, MA.

FitzGerald, D., I. Buynevich, R. Davis, Jr., and M. Fenster. 2002. New England tidal inlets with special reference to riverine-associated inlet systems. Geomorphology 48:179–208.

Kelley, J., D. Barber, D. Belknap, D. FitzGerald, S. van Heteren, and S. Dickson. 2005. Sand budgets at geological, historical, and contemporary time scales for a developed beach system, Saco Bay, Maine, USA. Marine Geology 214:117–142.

Lazzari, M.A. 2002. Epibenthic fishes and decapod crustaceans in northern estuar-ies: A comparison of vegetated and unvegetated habitats in Maine. Estuaries 25(6A):1210–1218.

Lazzari, M.A., and B. Tupper. 2002. Importance of shallow-water habitats for demersal fi shes and decapod crustaceans in Penobscot Bay, Maine. Environmental Biology of Fishes 63:57–66.

Lazzari, M.A., S. Sherman, C.S. Brown, J. King, B.J. Joule, S.B. Chenoweth, and R.W. Langton. 1999. Seasonal and annual variations in abundance and species composition of two nearshore fi sh communities in Maine. Estuaries 22(3A):636–647.

McDonough, C.J., and C.W. Wenner. 2003. Growth, recruitment, and abundance of juve-nile Striped Mullet (Mugil cephalus) in South Carolina estuaries. Fisheries Bulletin 101:343–357.

Musick, J. 1967. Designation of the hakes, Urophycis chuss and Urophycis tenuis, in ICNAF statistics. International Commission for the Northwest Atlantic Fisheries, Dartmouth, NS, Canada. Research Document No. 67/76.

Nichols, J., and C. Breder, Jr. 1927. The marine fi shes of New York and southern New England. Zoologica, NY 9:1–192.

Nizinski, M., B. Collette, and B. Washington, 1990. Separation of two species of sand lances, Ammodytes americanus and A. dubius, in the western North Atlantic. Fishery Bulletin 88:241–255.

National Marine Fisheries Service (NMFS). 2009. Proactive Conservation Program: Spe-cies of Concern- Offi ce of Protected Resources- NOAA Fisheries. Available online at http://www.nmfs.noaa.gov/pr/species/concern/. Accessed 22 March 2009.

Page, L., and B. Burr. 1991. A Field Guide to Freshwater Fishes. Houghton Miffl in Com-pany, New York, NY. 432 pp.

Reynolds, W., and M. Casterlin. 1985. Vagile macrofauna and the hydrographic environ-ment of the Saco River Estuary and adjacent waters of the Gulf of Maine. Hydrobio-logia 128:207–215.

Ross, M. 1991. Recreational Fisheries of Coastal New England. University of Massachu-setts Press, Amherst, MA. 279 pp.

Rozas, L.P., and T.J. Minello. 1997. Estimating densities of small fi shes and decapod crustaceans in shallow estuarine habitats: A review of sampling design with focus on gear selection. Estuaries 20:199–213.


Scott, W., and M. Scott. 1988. Atlantic Fishes of Canada. Canadian Bulletin of Fisheries and Aquatic Sciences 219. 731 pp.

Smith, K.L., I.C. Flores, and C.M. Pringle. 2008. A comparison of current and historical fi sh assemblages in a Caribbean island estuary: Conservation value of historical data. Aquatic Conservation: Marine and Freshwater Ecosystems 18:993–1004.

United States Geological Survey (USGS). 2009. USGS surface-water annual statistics for the nation. Available online at http://nwis.waterdata.usgs.gov/nwis/uv?site_no=01066000. Accessed 22 February 2009.

the fish assemblage structure of the saco river estuary

Documents