Mercury concentrations in Alaska Pacific halibut muscle relative to stable isotopes of C and N and other biological variables.
Total mercury concentrations ([THg]), δ15N and δ13C values were determined in muscle of 693 Pacific halibut caught in International Pacific Halibut Commission setline surveys in Alaska (2002-2011). Project goals were to evaluate whether 1) δ15N and δ13C varied with region, age, sex and length of halibut, and 2) muscle [THg] varied with δ15N and δ13C (feeding ecology) while accounting for sex, length, and region. Variation in [THg] was explained, in part, by halibut feeding ecology as [THg] increased with trophic position (increasing δ15N). Halibut from the western Aleutian Island region were the exception, with overall lower δ15N values and significantly higher [THg] than halibut from other Alaskan waters. This [THg] pattern has been observed in other Aleutian biota, possibly the result of northeasterly atmospheric movement of mercury emissions from Asia and/or other local sources and processes. The significantly lower δ15N values for these halibut warrants further investigation of halibut prey.
Institute of Arctic Biology, P.O. Box 757000, University of Alaska Fairbanks, Fairbanks, AK 99775-7000, USA; Arctic Beringia Program, Wildlife Conservation Society, P.O. Box 751110, Fairbanks, AK 99775, USA. Electronic address: rlmcguire@alaska.edu.
Rebecca
R
Bentzen
Department of Veterinary Medicine, P.O. Box 757750, University of Alaska Fairbanks, Fairbanks, AK 99775-7750, USA. Electronic address: jcastellini@alaska.edu.
J Margaret
JM
Castellini
Office of the State Veterinarian, Alaska Dept. of Environmental Conservation, 5251 Dr. Martin Luther King Jr. Ave., Anchorage, AK 99507, USA. Electronic address: bob.gerlach@alaska.gov.
Robert
R
Gerlach
International Pacific Halibut Commission, 2320 W. Commodore Way, Suite 300, Seattle, WA 98199-1287, USA. Electronic address: claude@iphc.int.
Claude
C
Dykstra
Department of Veterinary Medicine, P.O. Box 757750, University of Alaska Fairbanks, Fairbanks, AK 99775-7750, USA. Electronic address: tmohara@alaska.edu.
Todd
T
O'Hara
D000413:Alaska; D000818:Animals; D001837:Body Weights and Measures; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D005432:Flounder / Q000254:growth & development / Q000378:metabolism*; D020387:Food Chain; D062312:Islands; D008297:Male; D008628:Mercury / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000737:chemistry*; D009587:Nitrogen Isotopes / Q000032:analysis; D010140:Pacific Ocean; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical; D008628:Mercury
Alaska; C and N stable isotopes; Feeding ecology; Mercury; Pacific halibut