Contaminants in Fish and Wildlife

National Park Service POPs and Air Toxics Workshop

Themes

• Why care about air toxics ?• Potential sentinel species• Trends from the Arctic• Research gaps

Why Care about Air Toxics ?

• Biological Effects• Subsistence

Why Care ? - Biological Effects

• Survival• Reproductive success• Growth• Development• Immunology/disease• Behavior

What to Measure ?

• Chemical residues Whole body, eggs Feathers, fur, scat Select tissues (liver, kidney, fat, flesh)

• Biomarkers of exposure/effect Cytochrome P450 (PCBs, PAHs) HII4E (dioxins, furans, coplanar PCBs) Reproductive hormones Vitamins

What Species ?

Daphnia Photo: Paul Hebert, U. Guelph

Biomagnification

Factors Affecting Bioaccumulation

• Metabolism and selective retention of different chemicals

• Marine vs. terrestrial food webs

• Within a species, trophic level can differ with age and location

• Stable isotope analysis (e.g., 15N/14N)

Trophic Level vs. DDT Concentration

Source: AMAP Assessment Report

Trophic Level vs. PCB Concentration

Source: AMAP Assessment Report

Why Care ? - Subsistence

• Important issue in AK• Concern about contaminants in food• Some people abandoning traditional foods• Unhealthy alternatives, expense getting food to

villages• If NPS monitors biota in AK, issue will likely come up !

Subsistence Use Patterns

• Depend upon local availability• Cultural and traditional uses• Contaminants concentrations

differ:

Berries, plants Fish Birds Terrestrial Mammals Marine Mammals

Characteristics of an Ideal Species?

• Widespread/ubiquitous distribution, found in all Parks

• Sessile or limited range (non-migratory)• Likely to accumulate contaminants• Sensitive to contaminant effects• Easy to sample, won’t impact population• Ecologically important • Used for subsistence

Potential Sentinel Species

• Invertebrates• Freshwater fish • Anadromous fish (salmon)• Marine fish• Sea birds• Loons• Raptors• Riverine/semi-aquatic mammal• Large terrestrial mammals• Marine mammals

Invertebrates

• Zooplankton - ubiquitous, marine and freshwater, important food items, contaminants not well studied, low trophic level, trace level contaminants work

• Benthic insects - ubiquitous, contaminants not well studied, food items, different trophic groups, stream drift

• Mussels - sessile, filter feeder, important food items, also useful for PAHs, extensive database, limited to marine systems

Char and Trout

• Most freshwater, some anadromous• At least one species found in all Parks, but no single

species ubiquitous• Important for sport, subsistence and ecologically• Trophic position varies with size, species, habitat• Top predator in many freshwater systems• Canadian data variable (food web, lake size)• Circumpolar data for Arctic char (AMAP species)• Lake trout data also abundant

Northern Pike

• Freshwater predators• Extensive database in Canada and parts

of U.S.• Mercury often elevated in pike (good

biomonitor for mercury), but OC’s typically low in pike fillets

• Common in some AK Parks, but not found in many Western NPS units

USGS Photo

Anadromous Fish

• Salmon (also some trout and whitefish)• Important ecologically and for

subsistence, sport and commercial value

• Source of marine nutrients and contaminants (biological transport)

• Not found in all Parks• Contaminant accumulation and

sources outside Park boundaries• Whole fish, fillets, liver, kidney

Marine Fish

• Marine bottom-dwelling and/or predatory fish

• Baseline data exists, particularly from contaminated areas

• Fish from contaminated harbors show lesions, tumors, PAHs in fish bile, elevated body burdens, etc.

• Limited to marine systems

NOAA Photo

Seabirds

• Wide geographic distribution (i.e., gulls, cormorants)

• Eggs, feathers easy to collect• Wide range of trophic/feeding guilds• Subsistence food for some communities• Extensive database (gulls, cormorants,

some others)• Known effects (e.g., cormorants)• Migratory

Loons

• Wide geographic distribution• Eat fish, accumulate contaminants• Extensive database for metals (lead,

mercury)• Eggs, blood (metals), feathers (mercury)• Migratory

Raptors

• Feed high in food web• Bald eagle, osprey, falcons• Known effects (eggshell

thinning)• Wide geographic

distribution, but rare in many areas

• Often migratory, peregrine falcons highly migratory• Eggs easy to collect, feathers for

mercury, chick blood reflects local conditions

Riverine/Semi-aquatic Mammals

• River otters, mink• Toxicological benchmarks for mink, sensitive to PCBs• Pacific NW otters – reduced size of bacculum, testes• Wide distribution, but not abundant in many Parks• Organs (liver, kidney) • Mercury sampling - fur• Canadians – otter scat• Blood sampling ?

USGS-BRD Photo

Large Terrestrial Mammals

•Caribou, moose, elk found in many Parks•Important for subsistence•Charismatic mega-fauna•No single species found in all Parks•Herbivores (lower trophic position)•Caribou often highly migratory•Liver, kidney, meat•Metals (e.g., cadmium) elevated in kidney

Marine Mammals

• Polar Bear – top Arctic predator, extensive circumpolar database, known biological effects, limited distribution

• Belugas - well studied, accumulates contaminants, limited range

• Bowhead whales – growing database, feed on krill/plankton, limited range, migratory

NOAA Photo (modified)

Seals

• Ringed seals – primary polar bear prey, important for subsistence, limited range

• Harbor seals – extensive range but not used much for subsistence, existing database

Orcas

• Long-lived species• Resident populations (feed on salmon) vs.

transient populations (marine mammal prey)

• One of most heavily contaminated species known

• Ecological importance• Blubber samples less invasive• Limited to marine systems

Recommendations ?

• First must agree on some “basics”

Common species/group across all Parks vs. high priority species within each individual Park ?

Focus on non-migratory species ?

Subsistence implications important ?

Trend monitoring important ?

What level of expertise required to do sampling (e.g., eggs or feathers vs. blood samples)

Some Possible Choices: Ecological

• Mussels (good for coastal environment)• Resident predatory freshwater fish (e.g.

char or trout, possibly Northern Pike)• Mink or river otters• Raptors, seabirds or loons (eggs,

feathers)

Some Possible Choices: Subsistence

• Need to consider local uses, what is important in your area ?

• Salmon• Resident fish • Marine Mammals• Large terrestrial game animals• Migratory waterfowl• Bird eggs

Trends

• Peregrine Falcons from Alaska• Otters and Pike from Sweden• Canadian Ringed Seals

Trends- AK Peregrine Falcons

• Peregrine falcon study (’79-’95)• Egg samples from two sub-species

(North Slope, Interior AK)• Metals and OCs• Temporal trends

Trends – AK Peregrine Falcons

• Most OCs, including DDE, decreased with time

• PCBs declined less rapidly than other OCs

Trends - AK Peregrine Eggs

• Most metals decreased or did not change, except mercury, which may have increased (at least in one sub-species)

• Mercury concentrations in some cases approach levels which may impair reproduction

Trends - European Otters (Muscle)

Source: AMAP Assessment Report

Trends – Canadian Ringed Seals

Blubber from female seals

Source: AMAP Assessment Report

Trends – Canadian Ringed Seals

0

5

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1972-73 1987-93

Mercury in liver tissue (ug/g)

Source: AMAP Assessment Report

Trends – Swedish Pike

Lake Storvindeln, Sweden

Source: Swedish Environmental Protection Agency

Research Needs

• Toxicological thresholds for various species (and various chemicals)

• Implications of chronic non-lethal exposure

• Chemical mixtures (always present)

• “New” chemicals such as brominated flame retardants, perflurinated compounds (Scotchgard), etc.

• Communicating results to the public and managers in a way that is easy to understand, informative, accurate

Summary

• Monitoring biota for contaminants can be important for a variety of reasons (ecosystem integrity, species health, subsistence, track temporal change)

• Various biota and endpoints have different strengths/weaknesses

• No one single species is ideal for all purposes

• Goals must be clearly articulated

• Many outstanding research needs exist

Questions/Discussion ?