RESUMEN
Mortality of brook trout Salvelinus fontinalis and water chemistry were characterized in 6 headwater streams in the western Adirondacks of New York during spring 2015, 2016, and 2017 and compared with results from analogous tests done between 1980 and 2003 in many of the same streams, to assess temporal changes in toxicity and inorganic monomeric aluminum (Ali ) concentrations, and the role of Ali exposure duration on brook trout survival. The Ali concentrations of 2 and 4 µmol L-1 corresponded to low-to-moderate and high mortality thresholds, but prolonged exposure to ≥1 µmol Ali L-1 also produced mortality. The variability, mean, and highest Ali concentrations in Buck Creek year round, and in several other streams during spring, have decreased significantly over the past 3 decades. Logistic models indicate that Ali surpassed highly toxic concentrations in Buck Creek for 3 to 4 mo annually during 2001 to 2003 and for 2 to 3 wk annually during 2015 to 2017. The loss of extremely high Ali episodes indicates that toxicity has declined markedly between the 1989 to 1990, 2001 to 2003, and 2015 to 2017 test periods, yet Ali concentrations can still cause moderate-to-high and complete (100%) mortality. The logistic models illustrate how mortality of brook trout in several Adirondack streams likely decreased in response to the 1990 Amendments to the United States' Clean Air Act (which decreased acidity, Ali concentrations, and duration of toxic episodes) and offer a means to predict how changes in US regulations that limit emissions of NOx and SOx (and N and S deposition loads) could affect fish survival and stream ecosystems in this region and across the Northeast. Environ Toxicol Chem 2020;39:623-636. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Asunto(s)
Aluminio/toxicidad , Exposición a Riesgos Ambientales/efectos adversos , Ríos/química , Trucha , Contaminantes Químicos del Agua/toxicidad , Animales , Concentración de Iones de Hidrógeno , New York , Factores de TiempoRESUMEN
Contamination of fish populations with methylmercury is common in the region of the Laurentian Great Lakes as a result of atmospheric deposition and methylation of inorganic mercury. Using fish mercury monitoring data from natural resource agencies and information on tissue concentrations injurious to fish, we conducted a screening-level risk assessment of mercury to sexually mature female walleye (Sander vitreus), northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu), and largemouth bass (Micropterus salmoides) in the Great Lakes and in interior lakes, impoundments, and rivers of the Great Lakes region. The assessment included more than 43,000 measurements of mercury in fish from more than 2000 locations. Sexually mature female fish that exceeded threshold-effect tissue concentrations of 0.20 µg g(-1) wet weight in the whole body occurred at 8% (largemouth bass) to 43% (walleye) of sites. Fish at 3% to 18% of sites were at risk of injury and exceeded 0.30 µg g(-1) where an alteration in reproduction or survival is predicted to occur. Most fish at increased risk were from interior lakes and impoundments. In the Great Lakes, no sites had sexually mature fish that exceeded threshold-effect concentrations. Results of this screening-level assessment indicate that fish at a substantive number of locations within the Great Lakes region are potentially at risk from methylmercury contamination and would benefit from reduction in mercury concentrations.
Asunto(s)
Monitoreo del Ambiente/métodos , Peces , Lagos , Mercurio/análisis , Compuestos de Metilmercurio/análisis , Contaminantes Químicos del Agua/análisis , Animales , Lubina , Ecología , Femenino , Great Lakes Region , Mercurio/toxicidad , Compuestos de Metilmercurio/toxicidad , Percas , Valores de Referencia , Medición de Riesgo , Factores de Riesgo , Ríos , Contaminantes Químicos del Agua/toxicidadRESUMEN
Atmospheric emissions of mercury in the US are being reduced, but worldwide mercury emissions remain high. Mercury is also being removed from many consumer items. Changes over time in mercury concentrations in fish remain important to resource managers and the general public. There is hope that mercury concentrations in fish will decline, and the number of fish consumption advisories due to mercury will decrease. We compared mercury concentrations in yellow perch (Perca flavescens) from a group of Adirondack lakes with data collected 12-17 years earlier and found variable responses among lakes. We observed an average decline of 14% in yellow perch mercury concentrations over the past 15 years.