The Relationship between Organic Loading and Effects on Fish Reproduction for Pulp Mill Effluents across Canada

Abstract

This study builds upon the work of a multiagency consortium tasked with determining cost-effective solutions for the effects of pulp mill effluents on fish reproduction. A laboratory fathead minnow egg production test and chemical characterization tools were used to benchmark 81 effluents from 20 mills across Canada, representing the major pulping, bleaching, and effluent treatment technologies. For Kraft and mechanical pulp mills, effluents containing less than 20 mg/L BOD were found to have the greatest probability of having no effects. Organic loading, expressed as the total detected solvent-extractable components by gas chromatography/mass spectrometry (GC/MS), also correlated with decreased egg laying. Exceptions were found for specific Kraft, mechanical, and sulfite mills, suggesting yet unidentified causative agents are involved. Recycled fiber mill effluents, tested for the first time, were found to have little potential for reproductive effects despite large variations in BOD and GC/MS profiles. Effluent treatment systems across all production types were generally efficient, achieving a combined 82-98% BOD removal. Further reductions of final effluent organic loadings toward the target of less than 20 mg/L are recommended and can be realized through biotreatment optimization, the reduction of organic losses associated with production upsets and selecting best available technologies that reduce organic loadings to biotreatment.

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

“…This depression in gonad size has been seen in wild fish exposed to BKME in Sweden ( 79 , 82 ), Finland ( 83 ), and New Zealand ( 84 ), and was associated with a concomitant delay in age to maturation of fish in Canada ( 2 ) and Sweden ( 79 ). Further evidence of reproductive impacts have been seen in wild fish at other mills in Canada, USA (reviewed in 25 ) and Brazil ( 85 ), and in a variety of laboratory studies ( 28 ) demonstrating the potential of pulp and paper mill effluents.…”

“…Advanced maturation was also observed in brook stickleback ( Culaea inconstans ) sampled from Moberly Lake between 2007 and 2013 ( 86 ). In studies at other mills, improved reproductive performance was generally associated with reduced use of molecular chlorine, improved condensate handling and liquor spill control ( 25 ) and at mills with lower BOD and gas chromatographic total ion profiles ( 28 , 87 ). A study of female white sucker in the Androscoggin River, Maine, USA found that the pattern of reproductive impacts observed near 3 pulp mills disappeared after a switch to ECF bleaching, including reductions in gonad size and plasma E2 and increase in plasma T in fish exposed to effluent ( 88 ).…”

“…energy put into storage instead of reproductive development), participated in a joint government, industry and academia IOC study. A short-term fathead minnow ( Pimephales promelas ) reproductive test ( 26 ) was applied to test effluents from across the country ( 27 , 28 ). Kraft and mechanical pulp mill effluents containing less than 20 mg/L BOD were found to have the greatest probability of having no effects on egg production.…”

An International Perspective on the Tools and Concepts for Effluent Toxicity Assessments in the Context of Animal Alternatives: Reduction in Vertebrate Use

“…However, because the mode of action of EDCs is usually well understood, AOPs provide a tool to predict the biological and ecological functions at risk for fish populations in the receiving environment in case the assays detect endocrine‐disrupting activities. In a Canadian study, effects were detected in fish exposed to some pulp and paper effluents as reduced investment of energy into reproductive development, referred to as “metabolic disruption,” because fish still put energy into growth (Martel et al ). Further investigation of the cause of the effect determined that Kraft and pulp mill effluent with lower BODs reduced these effects in a fathead minnow short‐term reproductive test (Martel et al ).…”

“…In a Canadian study, effects were detected in fish exposed to some pulp and paper effluents as reduced investment of energy into reproductive development, referred to as “metabolic disruption,” because fish still put energy into growth (Martel et al ). Further investigation of the cause of the effect determined that Kraft and pulp mill effluent with lower BODs reduced these effects in a fathead minnow short‐term reproductive test (Martel et al ). With the monitoring program in place, it may be possible to evaluate whether reducing BOD in effluents also results in improvement in the receiving environment.…”