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National Park Service POPs and Air Toxics Workshop. Contaminants in Fish and Wildlife. 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.
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National Park Service POPs and Air Toxics Workshop Contaminants in Fish and Wildlife
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 ? Biomagnification Daphnia Photo: Paul Hebert, U. Guelph
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 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