Project: Impacts of Urban Effluents on Fish Health

PROJECT
Impacts of Urban Effluents on Fish Health

Program: Urban Effluents
Section Involved: River Ecosystems Research

Objective

The purpose of this project is to assess the impact of urban wastewater on fish health.

The first part of the project is a study of the relationship between the rate of parasitic infection in fish and their exposure to urban wastewater in the St. Lawrence River. If a positive or negative relationship is clearly established, these infections will serve as indicators of the degree of contamination of urban wastewater relative to its distance from the effluent outfall of the wastewater treatment plant.

Another part of the project involves studying the combined effect of parasites and contaminants on other types of functions. Fish reproduction, for example, is disturbed by the estrogen occurring in urban wastewater.

The Impacts of Urban Effluents on Fish

Contamination of the aquatic environment makes aquatic organisms vulnerable (Kemp and Spotila 1997). Fish immune systems, in particular, are weakened (Snieszko 1974; Sindermann 1979; Khan and Thulin 1991), leading to an increased incidence of parasites.

In addition to increasing the number of disease-causing parasites like protozoans and monogeneans, water pollution also reduces the diversity of parasitic species (Sulgostowka et al. 1987; Cone et al. 1993; Marcogliese and Cone 1996).

Methodology

Fish sampling stations are located within the dispersion plume of effluent discharged by Montreal’s wastewater treatment plant and also downstream of the outfall. Other stations upstream of the plume, such as Île Dorval and Îles de la Paix, serve as reference sites.

The species chosen for the study is the Spottail Shiner (Notropis hudsonius), because it occurs throughout the St. Lawrence aquatic system. Specimens were collected between 1998 and 2000 so as to establish different types of effects that effluents may have on fish health.

The specimens were thus used to measure indicators of endocrine disruption, to assess certain elements of the immune response and to determine the rate of parasitic infection.

Spottail Shiners, Notropis hudsonius

Initial Results

The project component dealing with the potential effects of urban effluents on the reproduction of fish populations, which involved tissue examination and sperm analysis, enabled researchers to establish the presence of intersexuality and to assess the motility of spermatozoa. The latter parameter was entrusted to a team at the Institut national de la recherche scientifique (INRS – Institut Armand-Frappier). The results of this work revealed endocrine disruption among fish populations exposed to urban wastewater effluents in the river. See Chemical Contaminants Disrupt Reproductive Function in Male Fish in the St. Lawrence River.

In 2002 and 2003, Yellow Perch, both severely and slightly infected by parasites, were sampled in parts of the river influenced by contaminants (Saint-Louis River) and in other parts away from pollution sources (Île Dorval). Certain indicators of oxidative stress have been measured in the tissues of these fish. Initial results indicate that parasitic infections can increase stress levels, particularly among fish captured in a contaminated area. See Interactions between Pollution and Parasitism in Fish.

A Comparison of Ecosystems

To compare the St. Lawrence ecosystem with that of other watercourses, Spottail Shiner specimens were also collected from Lake Ontario (Hamilton and Toronto) and the Richelieu River (Chambly). Parasitic fauna and vitellogenin in these specimens will be analysed and compared.

A Multidisciplinary Project with Numerous Collaborators

This project is part of the sampling program of the Urban Effluents Program at the St. Lawrence Centre and of its study of surfactants, conducted for the Urban Effluents Program.

In addition, this project is led in collaboration with researchers from other institutions. Work conducted in collaboration with a researcher at St. Mary’s University in Halifax reveals an increased number of microparasites in the waters downstream of the effluent discharged by Montreal’s wastewater treatment plant (Marcogliese and Cone 2001).

A collaborative effort with researchers at INRS – Institut Armand-Frappier, who are responsible for examining the effects of endocrine modulators and the immunological response of the fish in the study, already shows significant effects (production of vitellogenin).

At Concordia University in Montreal, another participating researcher is studying the life cycle and taxonomy of a parasite, the Eyefluke (Diplostomum spp.).

A post-doctoral fellow at the Institute of Freshwater Ecology and Inland Fisheries in Berlin also collaborated on the project, during an internship in Montreal in 2000-2001. He studied the effects of heavy metals on the free stages of parasites in the St. Lawrence River and on interactions between parasites and heavy metals in the Yellow Perch and the Spottail Shiner. This research will make it possible to verify if any contaminants have a direct impact on parasites, so as to correctly interpret the differences observed between stations. His work was funded in part by the Deutsche Akademie der Naturforscher Leopoldina.

Literature

Aravindakshan, J., V. Paquet, M. Gregory, J. Dufresne, M. Fournier, D. J. Marcogliese and D. G. Cyr. 2004. Consequences of xenoestrogen exposure on male reproductive function in spottail shiners (Notropis hudsonius). Toxicological Sciences 78: 156–165.

Aravindakshan, J., M. Gregory, D. J. Marcogliese, M. Fournier, and D. G. Cyr. 2004. Consumption of xenoestrogen-contaminated fish during lactation alters adult male reproductive function. Toxicological Sciences 81(1): 179–189.

Cone, D., D. J. Marcogliese, and R. Russel. 2004. The myxozoan fauna of spotnail shiner in the Great Lakes basin: Membership, richness, and geographical distribution. The Journal of Parasitology 90(5): 921–932.

Cone, D. K., D. J. Marcogliese, and W. D. Watt. 1993. Metazoan parasite communities of Yellow eels (Anguilla rostrata) in acidic and limed rivers of Nova Scotia. Canadian Journal of Zoology 71: 177–184.

de Bruyn, A. M. H., D. J. Marcogliese, and J. B. Rasmussen. 2002. Altered body size distributions in a large river fish community enriched by sewage. Canadian Journal of Fisheries and Aquatic Sciences 59(5): 819–828.

Kemp, S. J. and J. R. Spotila. 1997. Effects of urbanization on Brown trout Salmo trutta, other fishes and macroinvertebrates in Valley Creek, Valley Forge, Pennsylvania. American Midland Naturalist 138(1): 55–67.

Khan, R. A. and J. Thulin. 1991. Influence of pollution on parasites of aquatic animals. Advances in Parasitology 30: 201–238.

Marcogliese, D. J. 2003. Food webs and biodiversity: Are parasites the missing link? The Journal of Parasitology 89(6): S106–S113.

Marcogliese, D. J. and D. K. Cone. 2001. Myxozoan communities parasitizing Notropis hudsonius (Cyprinidae) at selected localities on the St. Lawrence River, Quebec: Possible effects of urban effluent. The Journal of Parasitology 87(5): 951–956.

Marcogliese, D. J. and D. K. Cone. 1997. Parasite communities as indicators of ecosystem stress. Parasitologia 39: 227–232.

Marcogliese, D. J. and D. K. Cone. 1996. On the distribution and abundance of eel parasites in Nova Scotia: Influence of pH. The Journal of Parasitology 82(3): 389–399.

Marcogliese, D. J., L. Gagnon Brambilla, F. Gagné, and A. D. Gendron. 2005. Joint effects of parasitism and pollution on oxidative stress biomarkers in Yellow perch (Perca flavescens). Diseases of Aquatic Organisms 36: 77–84.

Pietrock, M. and D. J. Marcogliese. 2004. Response to Morley and Lewis: Free-living endohelminths: the influence of multiple factors. Trends in Parasitology 20(3): 115–116.

Pietrock, M. and D. J. Marcogliese. 2003. Free-living endohelminth stages: At the mercy of environmental conditions. Trends in Parasitology 19(7): 293–299.

Pietrock, M., D. J. Marcogliese, and D. J. McLaughlin. 2002. Effects of cadmium upon longevity of Diplostomum sp. (Trematoda: Diplostomidae) cercariae. Chemosphere 47: 29–33.

Pietrock, M., D. J. Marcogliese, T. Meinelt, and D. J. McLaughlin. 2002. Effects of mercury and chromium upon longevity of Diplostomum sp. (Trematoda: Diplostomidae) cercariae. Parasitology Research 88: 225–229.

Sindermann, C. J. 1979. Pollution-associated diseases and abnormalities of fish and shellfish: A review. Fisheries Bulletin 76(4): 717–749.

Snieszko, S. F. 1974. The effects of environmental stress on outbreaks of infectious disease of fishes. Journal of Fish Biology 6: 197–208.

Sulgostowska, T., G. Banaczyk, and B. Grabda-Kazubska. 1987. Helminth fauna of flatfish (Pleuronectiformes) from Gdansk Bay and adjacent areas (Southeast Baltic). Acta Parasitologia Polonia 31: 231–240.