Thermal habitat segregation among morphotypes of whitefish ( Coregonus lavaretus: Salmonidae) and invasive vendace ( C. albula): a mechanism for co‐existence?
Summary Aquatic invasive species can have a variety of negative impacts on the ecosystems they invade. Carbon and nitrogen stable isotopes in the muscle tissue of aquatic organisms have proved useful for evaluating post‐invasion dietary shifts among species. However, oxygen and carbon stable isotope...
Published in: | Freshwater Biology |
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Main Authors: | , , |
Other Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2015
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Subjects: | |
Online Access: | http://dx.doi.org/10.1111/fwb.12660 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Ffwb.12660 https://onlinelibrary.wiley.com/doi/pdf/10.1111/fwb.12660 |
Summary: | Summary Aquatic invasive species can have a variety of negative impacts on the ecosystems they invade. Carbon and nitrogen stable isotopes in the muscle tissue of aquatic organisms have proved useful for evaluating post‐invasion dietary shifts among species. However, oxygen and carbon stable isotopes in fish otoliths have the potential to provide additional data on thermal habitat, diet and metabolism, when investigating interactions among sympatric native and invasive fishes. We conducted oxygen and carbon stable isotope analysis on the otoliths of three morphotypes of native whitefish ( Coregonus lavaretus ) and invasive vendace ( Coregonus albula ) at two sites within the sub‐Arctic Pasvik watercourse in northern Norway. Mean temperature use among morphotypes and species over the course of the growing season ranged from 7.5 °C to 11.2 °C. Otolith δ 13 C was significantly positively correlated to fish muscle tissue δ 13 C ( P < 0.05, r 2 = 0.53). Significant differences in temperature use and δ 13 C among morphotypes and between species were found in the downstream site but not the upstream site. Complementary partitioning of thermal and dietary resource use in the downstream site coincides with a higher abundance of whitefish, enabling the coexistence of both species. In contrast, vendace were dominant in the upstream site where no differentiation in resource use among morphotypes and between species was evident. This study demonstrates the usefulness of stable oxygen and carbon otolith isotopes for characterising resource use and highlights the importance of investigating thermal habitat use as a factor influencing the success of invasive fishes. |
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