A bioindicator approach to measurement of chronic stress in territorial populations of cunner, Tautogolabrus adspersus (Walbum, 1792), adjacent to a non-chlorinated pulp and paper mill in the Humber Arm Estuary, Newfoundland, Canada

Billiard, Sonya Marie (1996) A bioindicator approach to measurement of chronic stress in territorial populations of cunner, Tautogolabrus adspersus (Walbum, 1792), adjacent to a non-chlorinated pulp and paper mill in the Humber Arm Estuary, Newfoundland, Canada. Masters thesis, Memorial University of Newfoundland.

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Abstract

Signs of pathogenicity were quantified in cunner, Tautogolabrus adspersus, living adjacent (Birchy Cove and Summerside) to a non-chlorinated pulp and paper mill in the Humber River Estuary, western Newfoundland, compared with a reference site (Gillams) approximately 12 kilometers downstream of effluent outfall(s). Several bioindicators of pulp toxicity were utilized, including condition factor, organ somatic indices, macroscopic and microscopic irregularities, parasitofauna, age structure and induction of hepatic mixed function oxygenases. Condition factors were nonsignificant among sites in contrast to exaggerated growth at impact sites compared to Gillams' fish. Male and female gonadosomatic indices (GSIs) and histological analyses suggested a delay in spawning and/or gametogenesis of impacted fish versus mature, reference cunner. However, consideration of the short reproductive cycle of this species it is possible that polluted fish may have been sampled at the beginning of the maturational phase in comparison to Gillams' counterparts. Hepatosomatic indices (HSIs) were exaggerated at polluted sites and may reflect proliferation of hepatic smooth endoplasmic reticulum (SER). This was consistent with significant induction of 7 ethoxyresorufin deethylase at the Birchy Cove site, since SER is the site of both Phase-I and Phase-II enzymes. However, increased liver size may be attributed to vitellogenesis of female fish. No consistent differences were observed in visceralsomatic indices (VSIs), but splenosomatic indices (SSIs) were, in general, larger at Birchy Cove and Summerside than at Gillams. Percent splenic deposits did not demonstrate site significance. Histological surveys indicated more pronounced tissue pathology at Birchy Cove and Summerside. Quantification of Cryptocotyle lingua did not establish any site-specific trends, however, enteric parasitization was considerably more intense at the reference site compared to Birchy Cove and Summerside, possibly due to voiding or reduced proliferation in effluent-exposed cunner. Otolith analysis (1994) showed the mean age of the Gillams' sample to be significantly greater than at polluted sites. Chronic stress observed in cunners suggests that evidence of pulp-induced toxicity in this population is not necessarily due to chlorine constituents.

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