Reproductive success of Coregonus species in areas loaded by effluents from paper mills

Abstract

The annual reproductive success of Coregonus albula and C . lavaretus in some polluted and clean areas of the central parts of L. Paijanne was estimated in 1981-90 on the basis of occurrence of larvae in shore seine and seine net samples after the ice melted. In polluted areas (0-5 km from Kaipola paper mill) larvae of coregonids were found only occasionally. In semipolluted areas (5-15 km from the paper mill) the densities of larvae were usually less than 0.1 ind m-2. In 'clean' areas the mean densities of larvae ranged from 0.45 to 5.34 inds m-2. A relatively high reproductive success of vendace was observed in 1984-85, moderate success in 1982-83 and low success in 1986-90. The larvae of whitefish were scarce in both polluted and semipolluted areas and their density ranged from 0.01 to 0.15 ind m P 2 in clean shores. The highest density was observed in 1989. In spite of the improvement of the quality of water in the area in the 1980s, the reproductive success of coregonids is still low in a great part of the basin which may depend on adverse oxygen conditions of the hypolimnion and sediment and the toxic effects of the effluents.

Do laboratory exposures represent field exposures? Effects of sediments contaminated by wood industry on yolk-sac fry of rainbow trout (Oncorhynchus mykiss)

“…The altered bleaching methods and modern wastewater treatment have reduced the ecotoxicological impacts of the chemical wood industry in many countries, but the contaminated sediments still contain substances that are potentially harmful to wildlife (Ratia et al 2013). In the past, the wastewaters of pulp and paper industry caused recruitment failures in fish populations that led to the absence of salmonid species in downstream areas (Hakkari 1992, Hakkari andBagge 1992). The wastewaters of pulp and paper mills are considered to be of relatively low risk to fish nowadays, but salmonid populations are still largely absent.…”

Long-term changes in the water quality and fish community of a large boreal lake affected by rising water temperatures and nutrient-rich sewage discharges – with special emphasis on the European perch

“…Paper and pulp mill effluents cause eutrophication in the receiving water bodies (Huuskonen et al, 2000;Karels and Niemi, 2002). In Finland, the abundance of many salmonids and other fish species that are sensitive to pollution, mainly because they require a high concentration of dissolved oxygen in the water, has been found to decrease in waters altered by the effluents from paper and pulp mills Hakkari, 1992;Hakkari and Bagge, 1992;Karels and Niemi, 2002). On the other hand, total fish biomass is usually higher in the vicinity of the mills (Hakkari, 1992;Karels and Niemi, 2002) as a consequence of increased primary production.…”