Accumulation of Hormonally Active Substances by Wild White Sucker (Catostomus commersoni) Exposed to Effluents Discharged to the Wabigoon River

Abstract

A study was initiated in the spring of 2001 to determine if hormonally active chemicals are bioavailable to white sucker (Catostomus commersoni) residing in the Wabigoon River, downstream of the bleached kraft pulp mill and municipal sewage outfall located in Dryden, Ontario. Females collected during spawning migrations in May 2001 at a near-field exposure site exhibited increased condition factor, liver size and fecundity relative to those collected from a reference site. Liver samples within each site were pooled, soxhlet extracted and fractionated by gel permeation chromatography and HPLC according to octanol/water partition coefficient (Kow). Fractions were then tested to determine if fish accumulated ligands which bind to the goldfish testicular androgen receptor (AR) and sex steroid binding protein (SSBP). The levels of hormonally active substances were low in males whereas females had accumulated significant amounts of several chemicals capable of binding to the hormone receptors. The levels of ligands detected in pulp mill effluent samples were substantially reduced after secondary treatment. Fractionation of final effluent extracts showed only ligands for the AR in the hydrophobic region (log Kow >5), which corresponded to the activities detected in fish tissues from both sexes. It can be concluded that ligands for fish sex steroid receptors are present in final effluent after treatment at the pulp mill and chemicals with the same Kow are bioavailable to fish under spring freshet conditions. Further work at this site is necessary to determine the contribution of pulp mill and municipal sewage effluents to the physiological performance of fish in the Wabigoon River and to their burden of accumulated compounds.

Investigating the link between pulp mill effluent and endocrine disruption: Attempts to explain the presence of intersex fish in the Wabigoon River, Ontario, Canada

“…7c), an effect that was also documented in previous studies at 40% (v/v) by Kovacs et al [4], cannot be compared to male walleye as vitellogenin examinations were not performed. However, a previous study on the walleye of the Wabigoon River did examine vitellogenin and found no significant vitellogenin induction in near-field samples [25], although river effluent concentrations were estimated to be significantly lower than 60% (v/v) PME (20-40% [v/v] PME) and therefore not directly comparable to our mesocosm study. It would appear from our data that a lack of effect on females and a decrease in male testosterone are the only variables that display consistent results between our wild fish survey and mesocosm exposure.…”

“…The male from the present study had far more primary oocytes in its testes when compared to the two males from 2000. Occurrences of hormonal imbalance in fish are not limited to walleye, and have been seen in other species [25].…”

“…A study examining the wild fish of Wabigoon River was conducted by Hewitt et al [25] and focused primarily on the white sucker (Catostomus commersoni). Hewitt et al [25] found that females collected during spawning migrations at the same near-field location exhibited increased condition factor, liver size, and fecundity (larger ovaries) relative to those collected from a reference site.…”

“…Hewitt et al [25] found that females collected during spawning migrations at the same near-field location exhibited increased condition factor, liver size, and fecundity (larger ovaries) relative to those collected from a reference site. The conclusion of the Hewitt et al study [25] was that females had higher accumulations of hormonally active substances (ligands) than males, and these chemicals were responsible for the results seen in the white sucker.…”

“…Hewitt et al [25] found that females collected during spawning migrations at the same near-field location exhibited increased condition factor, liver size, and fecundity (larger ovaries) relative to those collected from a reference site. The conclusion of the Hewitt et al study [25] was that females had higher accumulations of hormonally active substances (ligands) than males, and these chemicals were responsible for the results seen in the white sucker. Given the results of the current study, the Golder study [28] and Hewitt et al [25], the effects of endocrine disruption in the walleye and white sucker not seen in the field mesocosm exposure, including intersex, shrunken testes, and increased fecundity needs to be addressed.…”