Large-scale assessment of mercury in sentinel estuarine fishes of the Florida Everglades and adjacent coastal ecosystems

• Autores: Douglas H Adams, Derek M. Tremain, David W Evans
• Localización: Bulletin of Marine Science, ISSN 0007-4977, Vol. 94, Nº. 4, 2018, págs. 1413-1427
• Idioma: inglés
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• Resumen

  • In Florida, USA, mercury can bioaccumulate in aquatic food webs to levels that are harmful to human and ecosystem health. Proposed efforts to restore hydrological flow in the Florida Everglades, which encompasses projects throughout central and south Florida, may alter the spatial distribution and temporal trends in mercury bioaccumulation in Florida fish populations. Monitoring of mercury in sentinel fish species permits assessment of changing conditions and can identify natural or anthropogenic impacts on upstream watersheds and predict regional influences on human and wildlife consumers of these fish species. From 2006 through 2008, we assessed total mercury in muscle of 545 gray snapper, Lutjanus griseus (Linnaeus, 1758), and 381 crevalle jack, Caranx hippos (Linnaeus, 1766), from 13 broad estuarine regions in central and south Florida, downstream of proposed Everglades restoration projects. For comparison, we assessed an additional 134 gray snapper collected from adjacent offshore waters in the Gulf of Mexico in 2007–2008 and 2014–2015. Collectively, these results indicate that Florida Bay and Card and Barnes sounds are mercury hot spots for both fish species in Florida estuarine and coastal ecosystems. Mean mercury concentrations in these species from Florida Bay were 1.7–2.5 times those measured in Atlantic coast estuaries (i.e., Loxahatchee estuary, St. Lucie estuary, and Indian River Lagoon). Mercury in snapper from offshore gulf waters did not reveal spatial differences from adjacent coastal estuaries, but did suggest concentrations in offshore snapper have remained stable in recent years. These results provide comprehensive baseline data that can be used to identify mercury hot spots in south Florida and for monitoring temporal and spatial changes in estuarine and coastal mercury concentrations as Everglades restoration plans are implemented.