Biological Resources of the Delaware River and Related

Environmental Issues

Kenneth J. Wagner, Ph.D

Background for K. WagnerBackground for K. Wagner• Born and raised in the Delaware River (DR) basin

(New Jersey, across the river from Philadelphia)• Escaped to NH for college (Dartmouth); extradicted in

1977 to Trenton for state service• Four years with NJDEP, including monitoring work

on the DR, during which Ken lived 300 ft from the DR at Washington’s Crossing

• Escaped again, to NY for grad school (Cornell) – not yet recaptured

• 23 years of water resource consulting, based in New England, but working all over, including in DR basin

0:20

Background for DRBCBackground for DRBC• The Delaware River Basin Commission was formed in

the early 1960s through multi-state and federal agreement, putting management of the watershed under an authority other than individual states or feds

• Representatives of each state and US government sit on the commission and make decisions

• Withdrawal and discharge permits are issued by DRBC• DRBC staff conduct studies and make recommendations• Scientific, economic and political elements all rolled into

a watershed approach to water resource management

0:50

Background for DRBCBackground for DRBCAddresses issues in:• 13,539 square miles• 236 watersheds

(HUC 11)• 4 states: DE, PA,

NJ, NY• 42 counties• 838 municipalities• 25 congressional

districts• 2 EPA Regions• 5 USGS offices

2:50

Background for DRBCBackground for DRBC• The DRBC has a

recent plan with key result areas

• Recognizes the complications and interactions associated with water resources and watershed activities

• Implementation is always a challenge

4:00

Biological Groups of InterestBiological Groups of Interest• Periphyton – attached algae• Aquatic Plants – emergent or submergent vascular

plants• Benthic Macroinvertebrates – bugs and other aquatic

invertebrates• Fish – best known stream biota• Reptiles and Amphibians – snakes, turtles, frogs,

salamanders with strong link to water• Birds and Mammals – water dependent species Some are more “charismatic” than others…

5:00

PeriphytonPeriphyton• Photosynthetic plants or bacteria growing

attached to some substrate

• Affected by substrate, light and water quality

• Limited water quantity effects; mainly presence and velocity

• Most often used as water quality indicators

6:50

PeriphytonPeriphyton

• Shifts among groups are meaningful; some field assessment possible with training

• Requires lab techniques for best quantity measurement

• Microscopic analysis of algal types is very useful, but requires considerable training and equipment

8:25

Aquatic Vascular PlantsAquatic Vascular Plants• Provide food and shelter for many other groups• Types and density usually determined by substrate and

light; only a few use water as a nutrient source• Water quantity impacts related to presence of adequate

water and flows that may destabilize community• Patchy distribution over space and time expected;

recovery from disturbance is fairly rapid

8:50

Aquatic Vascular PlantsAquatic Vascular Plants• Hot button issue is invasive species• Native species may be replaced by invaders, altering

ecology• Not all new species are invasive, and not all native

species are non-nuisances• Yet invasive species represent a major ecological and

economic threat

10:15

Benthic MacroinvertebratesBenthic Macroinvertebrates• Invertebrate fauna living among the substrate materials • Typically feed on algae, terrestrial inputs (e.g., leaves)

or each other• Sensitive to substrate and water quality• React to a lesser degree to water quantity; mainly

presence and velocity• Sensitive to food resources; especially periphyton,

drifting particles and leaf packs• Mussels are the most threatened among benthic

invertebrates, and are affected by both water quantity and quality issues

11:40

Benthic MacroinvertebratesBenthic Macroinvertebrates• Insects, Annelids, Crustaceans and Molluscs are the

main groups

15:10

Benthic MacroinvertebratesBenthic Macroinvertebrates• Abundance is important, although hard to characterize• Shifts among groups are very meaningful

– EPTs vs. Chironomidae– Similarity indices– Functional feeding groups

Distribution of Individuals among Feeding Groups

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Station 1 Station 2 Station 3 Station 4 Station 5

# o

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Total Shredders

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Total Detritovores

16:05

FishFish• Vertebrate biota with wide variety of forms and

ecology

• Consume some algae, mostly invertebrates, often each other

• Sensitive to cover (substrate, vegetation, banks), water quantity (depth, velocity), and water quality (especially oxygen and temperature)

17:40

FishFish• Types of fish present usually linked to water

quality

• Amount of fish present usually linked to physical habitat and by extension to water quantity – but this may not always be true

18:20

FishFish• Primary groups include salmonids (trout),

cyprinids (minnows) and centrarchids (bass/sunfish)

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FishFish

• Shifts among groups are very meaningful– Trout vs. other

species– Fluvial specialists

vs. fluvial dependents vs. habitat generalists

Fish biomass in OC-1

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Non-TroutBrown TroutBrook Trout

Fish biomass in OC-2

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Non-TroutBrow n TroutBrook Trout

19:20

FishFish• Shifts within groups

are very meaningful– Size distribution

(length or weight)– Growth rate (age

vs. length or weight)

– Condition factor (length vs. weight, evidence of parasites and disease)

Brook trout, OC-1 by season

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20:30

Reptiles and AmphibiansReptiles and Amphibians• Most forms are dependent on water during at least part

of life cycle• “Hibernation” over winter creates vulnerability• National trends in decline: pollution, habitat loss, disease

or other cause (or all of the above)?• Many protected forms; requires site specific knowledge

of populations when planning projects

21:10

Birds and MammalsBirds and Mammals• River is a source of food for many forms, shelter for

some• Water dependent bird species are highly visible and

popular• Water dependent mammals have variable “appeal”• Greater range and less complete dependence complicates

impact analysis

22:10

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Periphyton

• Used as WQ indicators; NWQA project, Limbeck and Smith 2007

• Generally indicate good quality in most of DR basin

• Upper DR less rich, less diverse, less pollution tolerant, and more indicative of clean conditions than Lower DR, which is indicative of elevated nutrient levels

• Some evidence of siltation and substrate instability

Limbeck & Smith. 2007. Pilot Study:Implementation of a Periphyton Monitoring Networkfor the Non-Tidal Delaware River. DRBC, Trenton, NJ

23:20

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Aquatic vascular plants

• Submergent Valisneria, Elodea, Potamogeton represent most biomass in Upper DR; reduced over a decade (1989-1997) presumably by reduced ammonia in discharges

• Emergent Nuphar, Peltandra, Pontederia, Zizania, Typha and Phragmites represent most biomass in Lower DR; sequesters up to 10% P, <1% N in marshes

• Invasive species threats not quantified

(http://www.state.nj.us/drbc/public.htm)

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Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Macroinvertebrates - freshwater

• Used as WQ indicators around discharges for compliance and to classify streams

• 8 species of mussels protected

Federally endangered Dwarf Wedge Mussel

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Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Macroinvertebrates - saltwater

• Horseshoe crab decline prompted harvest restrictions

• Shellfish harvest restrictions due to WQ

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Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Fish

• Major recreational resource – Versar creel census, state tributary surveys

• Freshwater, saltwater, anadromous, catadromous fish present and important

• Economic driver – recreational and commercial $ can be huge

• Political driver - fish don’t vote, but fishermen do

• Habitat used as a surrogate for fish abundance in instream flow studies

30:40

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Versar 2003 Delaware River Creel Census, for

PA FBC

• 7.5 month period, 120,000 angler trips, 2/3 non-tidal, 1/3 tidal

• Shad, herring, striped bass were primary species, catch down from a decade ago, but perceived to be due to lower effort

• Trout and bass from Upper DR

not discussed, but also significant

• Catch and release practices dominate

32:25

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Upper DR coldwater fishery

• Discharge from Cannonsville Reservoir creates coldwater conditions for 27 miles

• Another 50 miles of “coolwater” fishery; esp. smallmouth bass, but some trout

• Mainly rainbow and brown trout in DR, but many brook trout in tributaries, esp. headwaters

33:10

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Commercial eel fishery

• Catadromous eels live in freshwater in spring/summer, return to saltwater to spawn in the fall

• Caught in eel weirs, an old native american technique

• Worldwide food market

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Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources

Non-support from pH, mercury, PCB and bacteria

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Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Reptiles and amphibians

• 5 reptiles and 4 amphibians on protected list; bog turtle is prime example

• Bog turtle habitat widespread in DR corridor, prefer open (non-forested) wetlands

• May overwinter in undercut banks or areas prone to flood/drought

36:10

Key Delaware River Bio-ResourcesKey Delaware River Bio-Resources• Birds and Mammals

• Many water birds are resident

• Major resource for migratory birds

• Water dependent mammals common: beaver, muskrat, otter; bears and deer common in river corridor (esp scenic designated area)

• Multiple bird species have come off protected list as a result of DR programs (Eagle, Great Blue and Little Blue Heron, Cliff Swallow)

37:00

Delaware River IssuesDelaware River IssuesFrom DRBC Plan ppt:

Upper Region

•Funding for strategic watershed planning

•Stream buffers

•Basin transfers & efficiency

•Support for local planning

•Flow management

•Fisheries & Recreation

•Special Protection Waters program

Notes from experience:

Ecological integrity starts with the headwaters; the further up in the watershed the withdrawal, diversion or discharge, the more contentious it will be.

There is an ongoing effort to upgrade tributary classifications for better protection of resources

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Delaware River Issues (from plan)Delaware River Issues (from plan)Upper Region Water Supply System

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Delaware River Issues (from plan)Delaware River Issues (from plan)From DRBC Plan ppt:

Central Region

• Comprehensive watershed

management

• Environmental education

• Regional water supply &

land use planning

• Fish habitat & water quality

• Recreation & flow mgmt

• Power generation

• Partnerships

Notes from Experience:

Aside from protection of small tributaries (see Upper DR issues), improving the main river corridor to extend scenic status and related benefits has been proposed

This is an area of more active development and land use conversion (agric to residential); heightened competing uses is expected

40:15

Delaware River Issues (from plan)Delaware River Issues (from plan)Notes from Experience:

Poor water quality is an overriding consideration in this area

Many established industrial uses and navigation will collide with recreational uses if WQ improvements are made

Salinity intrusion with reduced freshwater flow is a primary supply concern

From DRBC plan ppt:

Lower Region

•Adequate supply, suitable quality

•TMDLs & water quality standards

•Salinity impacts: industry, drinking water & the estuary

•Watershed planning

•Tourism & recreation

•Navigation

•Partnerships, coordination & stewardship

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Delaware River Issues (from plan)Delaware River Issues (from plan)Lower Region Water Supply System (includes Central

and Lower from issues summary)

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Delaware River IssuesDelaware River IssuesFrom DRBC Plan ppt:

Bay Area Issues

•Non-point source issues

•Water supply enhancement options

•Science-based regulations

•Watershed-based planning & management

•Collaboration

•Salinity impacts

•Wetlands & oyster habitat

Notes from Experience:

WQ impacts on shellfish, water supply, and recreation remain primary concerned, not really emphasized in the list on the left

There is ongoing effort and controversy on the science-based regulation of key contaminants, along with pollutant trading

Water quantity is less an issue here

43:25

Example: Hoffman Springs ProjectExample: Hoffman Springs Project

• Water withdrawn from headwater springs in Lehigh County of PA

• Permit issued by DRBC with input from PADEP

• Questions regarding impacts on downstream fish

• Now through 10+ years of monitoring

• Applied site-specific model of flow-habitat-fish abundance to one stream segment

• Variability with overall flow regime evident, but impact of withdrawal not discernible

• Changing habitat appears to be a major factor

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Hoffman Springs ProjectHoffman Springs Project46:05

Hoffman Springs ProjectHoffman Springs Project

4.0 cfs

0.3 cfs

36 cfs

Average daily flow is 1.7 cfs

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Hoffman Springs ProjectHoffman Springs Project

Adult brook trout (>=150 mm TL) OC-1

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Avg WUA Without Withdrawal/100 Avg WUA With Withdrawal/100 Biomass (kg/ha)

Juvenile (<150 mm TL)

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Avg WUA Without Withdrawal/100 Avg WUA With Withdrawal/100 Biomass (kg/ha)

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Hoffman Springs ProjectHoffman Springs Project

Fall Total Brook Trout

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20062007

kg/ha = 7.748 (cfs) + 7.42Significance = 0.119 R2 = 0.275

30 kg/ha Class A level for brook trout

Relationship of flow to fish biomass

51:20

Hoffman Springs ProjectHoffman Springs ProjectRelationship of pool availability to fish biomass

Total trout biomass vs. % areal pool habitat in OC1

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Significance = 0.013R2 = 0.82

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Hoffman Springs ProjectHoffman Springs Project54:10

Hoffman Springs ProjectHoffman Springs Project

East Stream – change in pool area from 2004-05 storm

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Hoffman Springs ProjectHoffman Springs ProjectCONCLUSIONS

• Ontelaunee Creek headwaters support a thriving trout population; water quality is suitable, although certain human activities represent a threat

• Natural variability in flow impacts fish abundance; withdrawal may have a negative influence during dry periods, but any such effect is masked by the larger natural pattern

• Factors other than flow affect fish abundance; management for more or bigger fish could be accomplished with habitat manipulation (pools)

54:50

Overall Conclusions and “Tips”Overall Conclusions and “Tips”• DR has a lot of valuable biological resources and

represents an economic driver (commercial and recreational) as a result

• Water quality and water quantity are linked and must both be considered in management decisions

• Some of the desirable features of DR are a result of human actions (e.g., coldwater fishing due to deep water releases from constructed reservoirs); it is not a system “apart from humans”

• Undesirable features center on pollutant inputs and consumptive water withdrawals; the further upstream these occur, the greater the impact

56:20

Overall Conclusions and “Tips”Overall Conclusions and “Tips”• While all bio-resources deserve consideration, fish

are the pivotal resource; they have measurable value, no where else to go, and the community may not recover quickly after damage

• Protected species represent the greatest regulatory “hook”; approval of a project becomes much more difficult if protected species may be impacted

• While the DRBC has political shortcomings, it is a highly appropriate institution by virtue of its watershed focus, and offers a single point of contact and defined process for evaluating projects and making management decisions

57:35

Overall Conclusions and “Tips”Overall Conclusions and “Tips”• When evaluating a possible withdrawal, consider:

• Where does it occur relative to known bio-resources?

• When does it occur relative to the needs of specific biota?

• What is the magnitude of withdrawal compared to the range of possible flows at the point of withdrawal?

• What other factors mitigate or exacerbate any impact of the withdrawal?

• What economic and socio-political drivers are important in addition to biological impacts?

59:00

Delaware River Bio-ResourcesDelaware River Bio-ResourcesQuestions and Comments?

Get good info before reacting; it is easy to be mislead!