Trends in Marine Plankton Biodiversity over the 21st Century under Different Climate Change Scenarios
Marine plankton are at the base of the marine food webs. They perform essential ecological functions such as biological carbon sequestration and food provision to higher trophic levels. However, they are subject to anthropogenic climate change, and the impacts of different climate change scenarios o...
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| Other Authors: | , , |
| Language: | English |
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ETH Zurich
2023
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| Online Access: | https://hdl.handle.net/20.500.11850/652200 https://doi.org/10.3929/ethz-b-000652200 |
| Summary: | Marine plankton are at the base of the marine food webs. They perform essential ecological functions such as biological carbon sequestration and food provision to higher trophic levels. However, they are subject to anthropogenic climate change, and the impacts of different climate change scenarios on marine plankton biodiversity and habitat are poorly quantified. In this study, we use an ensemble of species distribution models to project habitat suitability index for a total of 843 marine plankton species (326 phytoplankton and 517 zooplankton) under three climate change scenarios (RCP2.6, RCP4.5 and RCP8.5) from 2012-2100. The differences in plankton biodiversity among the three RCPs are substantial. In RCP2.6, compared to the baseline (2012-2031), the global mean relative increase in plankton species richness by the end of the 21st century (2081-2100) is only 1.6%. This relative change increases to 3.4% in RCP4.5 and further to 8.0% in RCP8.5. From RCP2.6 to RCP8.5, there is a remarkable expansion of species richness change hotspots. In RCP8.5, the species richness change hotspots will cover three fourths of the global surface ocean from 60°N to 60°S by the end of the 21st century. The majority of plankton species (85%) will shift poleward in the future in response to ocean warming. Furthermore, there is a significant acceleration of poleward shift, from 3.76 km/dec in RCP2.6 to 19.95 km/dec in RCP8.5. The Arctic Ocean is the ocean basin that will experience the highest level of species turnover in plankton assemblages under all RCP scenarios, which indicates a high sensitivity to climate change in this region. Species turnover in the Arctic Ocean amounts to 0.45 in RCP8.5, which means that nearly half of the species in plankton assemblages will be replaced by the end of the 21st century. Phytoplankton and zooplankton are different in their biodiversity responses to ocean warming in the tropics: Phytoplankton species richness will increase under all RCP scenarios, by contrast, zooplankton species richness will ... |
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