Thermal histories, stress, and metabolic rates of chinook salmon (Oncorhynchus tshawytscha) in Lake Ontario: evidence from intra-otolith stable isotope analyses
| Autor: | D. J. Stewart, William P. Patterson, J. N. Bowlby, Christopher M. Wurster, T. J. Stewart |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
education.field_of_study
Chinook wind biology Stable isotope ratio Aragonite Population Pelagic zone Aquatic Science engineering.material biology.organism_classification Fishery medicine.anatomical_structure engineering medicine Oncorhynchus Environmental science Life history education Ecology Evolution Behavior and Systematics Otolith |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 62:700-713 |
| ISSN: | 1205-7533 0706-652X |
| DOI: | 10.1139/f04-241 |
| Popis: | We describe thermal histories for Lake Ontario chinook salmon (Oncorhynchus tshawytscha) as determined from otolith δ 18 O thermometry using computer-controlled micromilling techniques to recover otolith aragonite at subseasonal resolution. We find that during the summer months chinook salmon inhabited epilimnetic waters with tem- peratures of ~19-20 °C as far back as the late 1980s. Chinook would approach but rarely exceed their reported upper incipient lethal limit of approximately 22 °C, which suggests that these fish were seeking water with temperatures as high as was tolerable while otolith growth occurred. These results contrast with expected midsummer temperatures for this cold-water salmonine. Bioenergetic simulations indicate significant stress imposed upon chinook salmon. We esti- mate consumption to be up to 20% more and gross conversion efficiency 18% less annually relative to nominal simula- tions where chinook salmon are modeled nearer their preferred temperature, reinforcing previous inferences that the chinook salmon population may be near the limits of sustainability. We also find a strong negative correlation between δ 18 O and δ 13 C values. Therefore, seasonal and ontogenetic variation in δ 13 C values of chinook salmon otoliths appear to be related to metabolic rate during pelagic residence and may provide an indirect method for evaluating field activity and other aspects of fish life history. Resume : Nous decrivons l'histoire thermique des saumons quinnat (Oncorhynchus tshawytscha) du lac Ontario d'apres la thermometrie δ 18 O des otolithes a l'aide de techniques de moulinage sous controle d'ordinateur pour recuperer l'aragonite des otolithes a une echelle de resolution inferieure a une saison. Durant les mois d'ete, les saumons quinnat |
| Databáze: | OpenAIRE |
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