title: Declining Mercury Concentrations in Bluefin Tuna Reflect Reduced Emissions to the North Atlantic Ocean.
abstract: Tunas are apex predators in marine food webs that can accumulate mercury (Hg) to high concentrations and provide more Hg (∼40%) to the U.S population than any other source. We measured Hg concentrations in 1292 Atlantic bluefin tuna (ABFT, Thunnus thynnus) captured in the Northwest Atlantic from 2004 to 2012. ABFT Hg concentrations and variability increased nonlinearly with length, weight, and age, ranging from 0.25 to 3.15 mg kg-1, and declined significantly at a rate of 0.018 ± 0.003 mg kg-1per year or 19% over an 8-year period from the 1990s to the early 2000s. Notably, this decrease parallels comparably reduced anthropogenic Hg emission rates in North America and North Atlantic atmospheric Hg0concentrations during this period, suggesting that recent efforts to decrease atmospheric Hg loading have rapidly propagated up marine food webs to a commercially important species. This is the first evidence to suggest that emission reduction efforts have resulted in lower Hg concentrations in large, long-lived fish.
authors.affiliation: School of Marine and Atmospheric Sciences, Stony Brook University , Stony Brook, New York 11794-5000, United States.
authors.forename: Cheng-Shiuan
authors.initials: CS
authors.lastname: Lee
authors.affiliation: Large Pelagics Research Center, School for the Environment, University of Massachusetts-Boston , Gloucester, Massachusetts 01931, United States.
authors.forename: Molly E
authors.initials: ME
authors.lastname: Lutcavage
authors.affiliation: Large Pelagics Research Center, School for the Environment, University of Massachusetts-Boston , Gloucester, Massachusetts 01931, United States.
authors.forename: Emily
authors.initials: E
authors.lastname: Chandler
authors.affiliation: Harvard University Center for the Environment, Harvard University , Cambridge, Massachusetts 02138, United States.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Madigan
authors.affiliation: School of Marine and Atmospheric Sciences, Stony Brook University , Stony Brook, New York 11794-5000, United States.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Cerrato
authors.affiliation: School of Marine and Atmospheric Sciences, Stony Brook University , Stony Brook, New York 11794-5000, United States.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Fisher
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D005399:Fishes; D008628:Mercury; D009656:North America; D014413:Tuna
chemical_list: D008628:Mercury