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TitleEvidence of chronic stress in winter flounder, Pleuronectes (= Pseudopleuronectes) americanus living adjacent to a pulp and paper mill in St. George's Bay, Western Newfoundland
AuthorBarker, Duane Edward
DescriptionThesis (M.Sc.)--Memorial University of Newfoundland, 1993. Biology
Paginationxi, 101 leaves : ill., map.
SubjectWinter flounder--Effect of stress on; Winter flounder--Effect of water pollution on; Wood-pulp industry--Newfoundland and Labrador--Port Harmon--Environmental aspects
Degree GrantorMemorial University of Newfoundland. Dept. of Biology.
Spatial CoverageCanada--Newfoundland and Labrador--Port Harmon
NotesBibliography: leaves 92-100.
AbstractWinter flounder, Pleuronectes (= Pseudopleuronectes) americanus, living adjacent to a pulp and paper mill at Port Harmon, Stephenville, Newfoundland, were compared with flounder from a reference site, St. George's, 12 km from the mill, for signs of chronic stress. Several bioindicators of stress in fish were employed, including condition factor, organ somatic indices, haematological values, external lesions, and parasitofauna. Winter flounder from Port Harmon, (effluent site) showed significantly lower condition factors (K-factors) and hepatosomatic indices (HSI) indicative of depleted energy reserves, and physiological impairment, than those from St. George's. Delayed spawning was evident in both male and female winter flounder from Port Harmon compared with those from St. George's. Blood haemoglobin, haematocrit, and lymphocyte levels were significantly lower at Port Harmon, than in samples from St. George's. Fin necrosis of the caudal, dorsal and anal fins, was greater (in terms of prevalence and intensity) in flounder from Port Harmon. The prevalence and intensity of intestinal nematodes was significantly higher at Port Harmon, than St. George's; possibly the result of differences in diet. Conversely, the prevalence and intensity of intestinal acanthocephalans was significantly lower at Port Harmon, and was possibly related to effluent discharge. No differences were found in a comparison of prevalence and intensity of intestinal digeneans. The prevalence and severity of infection of a parasitic microsporan protozoan, Glugea stephani, and the encysted metacercaria of the digenean, Cryptocotyle lingua, were, however, significantly higher among flounder from Port Harmon. Anaemia, low lymphocyte levels, a high prevalence of fin necrosis and parasitemias (Glugea stephani, Cryptocotyle lingua) are all suggestive of immunosuppression. Since the above differences were not attributed to differences in basic water parameters (temperature, salinity, conductivity, pH, and dissolved oxygen) at the two sites, the chronic stress evident in winter flounder from Port Harmon is most likely attributed to pulp mill effluent discharged at Port Harmon.
Resource TypeElectronic thesis or dissertation
FormatImage/jpeg; Application/pdf
SourcePaper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
Local Identifier76165930
RightsThe author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
CollectionElectronic Theses and Dissertations
Scanning StatusCompleted
PDF File(12.95 MB) --
CONTENTdm file name96897.cpd