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A 30 year study of impacts, recovery and development of critical effect sizes for endocrine disruption in white sucker (Catostomus commersonii) exposed to bleached-kraft pulp mill effluent at Jackfish Bay, Ontario, Canada
Citation:
Ussery, E., M. McMaster, M. Servos, K. Muntkittrick, AND D. Miller. A 30 year study of impacts, recovery and development of critical effect sizes for endocrine disruption in white sucker (Catostomus commersonii) exposed to bleached-kraft pulp mill effluent at Jackfish Bay, Ontario, Canada. Frontiers in Endocrinology. Frontiers, Lausanne, Switzerland, 12:664157, (2021). https://doi.org/10.3389/fendo.2021.664157
Impact/Purpose:
Jackfish Bay is an isolated Bay on the north shore of Lake Superior, Canada that has received effluent from a large bleached-kraft pulp mill since the 1940s. Studies conducted in the late 1980s found evidence of reductions in sex steroid hormone levels in multiple fish species living in the Bay. Early studies documented increased growth, increased condition, increased storage of internal fat, increased relative liver weights suggesting increased food resources, but reduced gonadal sizes, delayed sexual maturation, and altered levels of circulating sex steroid hormones in white sucker (Catostomus commersonii). These studies provided some of the first pieces of evidence of endocrine disruption in wild animals. Studies on white sucker have continued at Jackfish Bay and followed fish responses to installation of secondary waste treatment (1989) and changes in the pulp bleaching process (1990s), as well as fish responses during facility maintenance shutdowns and during a series of facility closures associated with changing ownership (2000s). During the 30 years of studies, more than 75 physiological, endocrine, chemical and whole organism endpoints have been studied and the review provides important context for the complexity of endocrine responses, species differences, and challenges with extrapolation. Population modelling of the initial reproductive alterations to white sucker predicted a 30% reduction in the population size, however with improvements over the last couple decades those population impacts improved considerably. This long term review provides important perspectives for understanding long term variability, the ecological relevance of changes, and concepts around normal ranges that impact the design and interpretation of monitoring studies.
Description:
Jackfish Bay is an isolated Bay on the north shore of Lake Superior, Canada that has received effluent from a large bleached-kraft pulp mill since the 1940s. Studies conducted in the late 1980s found evidence of reductions in sex steroid hormone levels in multiple fish species living in the Bay. Early studies documented increased growth, increased condition, increased storage of internal fat, increased relative liver weights suggesting increased food resources, but reduced gonadal sizes, delayed sexual maturation, and altered levels of circulating sex steroid hormones in white sucker (Catostomus commersonii). Intensive study documented disruptions at multiple sites along the pituitary-gonad axis in white sucker and a delay in sexual maturity was confirmed in lake whitefish (Coregonus clupeaformis). These studies provided some of the first pieces of evidence of endocrine disruption in wild animals. Studies on white sucker have continued at Jackfish Bay and followed fish responses to installation of secondary waste treatment (1989) and changes in the pulp bleaching process (1990s), as well as fish responses during facility maintenance shutdowns and during a series of facility closures associated with changing ownership (2000s). Collections in 2018 and 2019 extended the time series of spring and fall collections examining potential recovery, resulting in a 30 year study of fish health impacts, endocrine disruption, chemical exposure, and ecosystem recovery. Differences in body size, liver size, gonad size and condition persist, although changes in liver and gonad indices are much smaller than in the early years. Population modelling of the initial reproductive alterations predicted a 30% reduction in the population size, however with improvements over the last couple decades those population impacts improved considerably. The long term review provides important perspectives for understanding long term variability, the ecological relevance of changes, and concepts around normal ranges that impact the design and interpretation of monitoring studies. During the 30 years of studies, more than 75 physiological, endocrine, chemical and whole organism endpoints have been studied and the review provides important context for the complexity of endocrine responses, species differences, and challenges with extrapolation.
