PTS: 23029TZ.8.0 Title: PWRC-Mercury in tree swallow foods and tissues at Acadia National Park
Keywords:Contaminants, toxicants, stressors, fish, wildlife, natural resources. Leaders: * Longcore, Jerry R., jlongcore@usgs.gov, 207-581-2874, FAX 207-581-3783, 5768 South Annex A The University of Maine, Orono, ME 04469-5768 Communication Plan: These data will be used to 1) to document the extent of mercury contamination in the trophic levels of two Acadia National Park ponds and, 2) to provide data to support lowering atmospheric deposition of toxic compounds on federal parks and refuge lands. Further application will be made by using data from the park as a reference site in 1999 for a comparison with a companion site at an EPA Superfund Site in Maine. Results from this investigation will be published in a peer-reviewed journal. Highlights and Key Findings: After data and biological samples (nestlings, eggs, food boli, feathers) were collected in the field in spring and summer of 1997 from the mercury-contaminated ponds at Acadia and the control site in Orono, ME, laboratory work included the preparation of carcass, egg, food boli, and plumage samples for analyses for mercury. All feathers used as nest lining have been identified by collaborators from the National Museum of Natural History, as from 13 different avian species. In 1997, eggs and nestlings were obtained from 5 clutches at the Park (4 Seal Cove Pond, 1 Hodgdon Pond). Mean (SD) amounts of mercury (ng/g)were 304 (207) in egg, 44(7)in nestling, and 1519 (318) in feathers. Amounts of mercury at the control site in Orono, ME were 256 (33) in egg, 42 (9) in nestling, and 2014 (625) in feathers. Fledging success at both sites equalled 90-100%. Preliminary inspection of data for Acadia samples indicate that ng/g averaged 90 ng/g in food boli, 37 ng/g in nestling carcass, and 2251 ng/g in feathers. Egg hatchability was 60-100%/clutch and fledging success was 100%/clutch. Average amounts of total mercury (ng/g,wet weight)for each Acadia NP pond equaled: in food boli 72-291 ppb, in carcasses 30-73 ppb, and in feathers 1,080-4,493 ppb. Among years and ponds the factor of increases were: from food boli to eggs, 1.2-6.1, from food to carcass, 0.23-0.56, and from food to feathers, 8.5-27.7. Mean amounts of mercury in food boli, carcasses and featers was different among some ponds some years, but overall mercury in tree swallow samples from Aunt Betty Pond ranked the highest. Effects on reproduction were manifest as unhatched eggs, which ranged from 27 to 62% of all clutches having one or more unhatched eggs; almost all of the hatched young lived to fledge regardless of pond or year. Objectives: This task addresses goal 4 of Contaminants Biology: Evaluate the ecological risk posed by contaminants. This task addresses goal 4 of Status and Trends: Monitor and assess environmental staus and trends (BEST).
It would be useful to obtain data for an insectivorous avian species to fill in another trophic level, which already includes, water, sediment, fish, reptiles, and aquatic invertebrates (insects). Thus, we wish to evaluate the biomagnification of mercury in tree swallows (Tachycineta bicolor) that feed on aquatic insects (t.A. Haines, study plan) from these two ponds. We propose to compare response data of tree swallows from these two ponds to data for tree swallows at an inland site, which will serve as a control. We will need to obtain mercury residue data in nestlings, and perhaps in eggs, feathers of nestlings, and in nestling foods. We intent to measure the reproductive variables of egg size and weight, clutch size, hatching success of eggs and fledging success of nestlings.
Specific objectives of the project were (1) to expand the breadth of an ongoing study by Dr. Haines (Sources, Fate, and Effects of Mercury in Aquatic Systems at Acadia National Park, Maine, and Cape Cod National Seashore, Massachusetts) to include an insectivorous bird species, (b) to characterize the extent of mercury contamination and transfer from lower trophic levels (i.e., aquatic insects) to the insectivorous tree swallow, and (c) to evaluate the potential of using feathers of other species that are collected by tree swallows to insulate their nests to characterize mercury contamination in the surrounding avian community. After the second year of study it was possible to add an additional year (1999) of data collection by keeping the Acadia NP study site as a control site for comparison to a Superfund site in MA being evaluated in a companion study. By doing this, we were able to collect an adequate sample from an additional pond (Aunt Betty Pond) on Acadia NP. Statement of Problem: Contamination of aquatic wildlife by mercury (Scheuhammer 1987, Heinz 1996) is well known and is of increasing concern for top of the food-chain predators because mercury bioaccumulates and biomagnifies through trophic levels (Spry and Wiener 1991, Wiener and Spry 1996). Mercury is stored in fish mostly in skeletal muscle (i.e., as monomethly mercury; Lasora and Allen-Gill 1995), which presents a hazard to piscivorus wildlife and to humans (Clarkson 1992) when fillets of fish are eaten by humans. In this regards, mercury accounts for nearly two-thirds of the human health advisories issued for contaminants in fish and advisories include 34 states, involving over a thousand water bodies (USEPA 1995). In Maine, mean amounts of mercury (ug/g. wet wt.) ranged
Between 0.28 and 0.88 for 5 nonsalmonid species and 0.26 to 0.42 ug/g in 4 salmonid species, with concentrations exceeding 1.0 ug/g for smallmouth bass (Micropterus dolomieu), white perch (Morone Americana) and chain pickerel (Esox niger)(Stafford and Haines 1997). More specifically, at Arcadia National Park, concentrations of mercury ranged from 0.53-2.77 ug/g in 5 chain pickeral and 1.02 ug/g in 1 white perch from Seal Cove Pone and mercury averaged 2.11 ug/g in 7 smallmouth bass from Hodgdon Pond with the highest mercury levels being 3.9, 3.4, 2.8 and 2.3 ug/g in individual fish (T.A. Haines, unpubl. Data). Mercury in fish, which is accumulated through biomagnification through the aquatic food web, is attributed to atmospheric deposition (Akielaszek and Haines 1981) in Maine because sample lakes are remote from point sources of mercury discharge. The aquatic invertebrates fed on by fish are also eaten by insectivorous avian species, e.g., the tree swallow (Holroyd 1983, Quinney and Ankney 1985). Primary food of nestling tree swallows in Ontario were mayflies (Ephemeroptera; Hexagenia), aquatic Diptera (especially Nematocera midges) dragonflies (Odonota) and Lepidoptera (Holroyd 1983). At another location in Ontario (Blancer and MnNicol 1991) numerically important prey species fed to tree swallow nestlings were chironomid midges (35%), several mayfly genera, and homopterans, but on a dry mass basis horseflies (Tabanus; 48%) and burrowing mayflies (Hexagenia, 13.4%) were most important. Aquatic insects, including Hexagenia readily take up mercury and other metals (Dukerschein et al. 1992). Characteristics of the aquatic community all can influence foraging (McCarty 1997) and breeding success (Blancer and McNicol 1988, St Louis and Bartow 1993) in tree swallows. Because tree swallows breed extensively throughout North America and readily use next boxes (Robertson and Rendell 1990, Holyroyd 1983, Sheppard 1977) they have been used as a monitor of methylmercury dynamics related to experimental acidification of a wetland (St. Louis et al. 1996). 2003 Progress: A final report for the Acadia National Park was drafted, but not fully completed, because of the effort to prepare a manuscipt for a compliation of all mercury work at the park. The manuscript was submitted for review to meet a 12 Sept 2003 deadline. Additional data on tree swallow growth related to mercury contamination have been analyzed and another manuscript is in preparation. Analyses for the second manuscript on tree swallow growth related to mercury in tissues was completed. The manuscipt will be drafted in FY04. 2003 Statement of Work: Data will be analyzed. Data sets include mercury in tree swallow foods and tissues, reproductive performance, total mercury versue methylmercury, feeding rates, and comparisons between data from the park and from Devens, MA, an EPA Superfund Site. A final technical report will be prepared for Acadia National Park and one or two manuscripts will be prepared for journals. 2004 Statement of Work: The draft final report for Acadia National Park, NPS, will be completed. The additional data analyses on tree swallow growth as related to mercury will be completed and the second manuscript will be completed and submitted to a peer-reviewed journal. Product: Report Delivered in review Product: Report Delivered Longcore, J.R., R.Dineli, and T.A. Haines. 2006. In press, Mercury and growth of tree swallows at Acadia National Park, Mt. Desert Island, and at Orono, ME., USGS
Thanks to USGS Patuxent Wildlife Research Center for hosting this page for the USGS Biology Science Staff.
U.S. Department of the Interior |
U.S. Geological Survey