Wirkungen von CO2 auf die Temperaturtoleranz und Fitnessindikatoren einer Crustaceenart aus verschiedenen Klimazonen
Anthropogenic CO2 emissions threaten marine ecosystems by increasing water temperature and ocean acidification. In this study the impacts of climate change on the thermal tholerance of the spider crab Hyas araneus (L.) were investigated. Population comparisons were conducted on populations from Sval...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | German |
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Universität Bremen
2010
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| Online Access: | https://media.suub.uni-bremen.de/handle/elib/39 https://nbn-resolving.org/urn:nbn:de:gbv:46-00101742-13 |
| Summary: | Anthropogenic CO2 emissions threaten marine ecosystems by increasing water temperature and ocean acidification. In this study the impacts of climate change on the thermal tholerance of the spider crab Hyas araneus (L.) were investigated. Population comparisons were conducted on populations from Svalbard (79°N, habitat temperature 0 - 6 °C) and Helgoland (54°N, habitat temperature 3 - 18 °C), representing the species s northern and southern distribution range which is the temperate Northeast Atlantic to the Sub-Arctic region. The thermal tolerance window of H. araneus from Helgoland (54°N) was determined by measurements of the heart rate and hemolymph oxygen partial pressure upon temperatures ranging from 0 to 25 °C. Elevated CO2-concentrations induced a lowering of upper critical temperature from beyond 25 °C down to 23.5 °C (710 ppm). An increase of environmental CO2 concentrations to 3000 ppm caused a concomitant drop of the upper critical temperature to 21.1 °C. These results indicate, that the H. araneus population from Helgoland will knock on its physiological borders by synergistic effects of warming (up to 22.5 °C) and elevated CO2 concentrations. Additionally, studies on the impacts of climate change on early, potentially more sensitive life stages were conducted. Larvae of H. araneus of both populations were exposed to different temperatures and CO2 concentrations, revealing a temperature-dependent development. Larvae of Helgoland grew faster and had a higher fitness compared to those from Svalbard. Elevated CO2 concentration caused a disturbed development in all stages of both populations. Helgoland megalopae displayed the highest sensitivity against enhanced CO2 concentrations. In contrast, megalopae from Svalbard were more sensitive to warming. The negative effects of both, CO2 and temperature lead to the conclusion that the megalopae is a putative bottleneck stage during the species development. Moreover, the effect of climate change was investigated on the calcification capacity of the H. araneus ... |
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