Multi‐decadal range changes vs. thermal adaptation for north east Atlantic oceanic copepods in the face of climate change |
| |
Authors: | Martin Edwards Clare Ostle Owen G Bodger Patricia L M Lee Antony W Walne Graeme C Hays |
| |
Institution: | 1. The Laboratory, SAHFOS, , Plymouth, PL1 2PB UK;2. Marine Institute, University of Plymouth, , Plymouth, PL4 8AA UK;3. School of Environmental Sciences, University of East Anglia, , Norwich, NR4 7TJ UK;4. Institute of Life Sciences, Swansea University, , Swansea, SA2 8PP UK;5. Department of Biosciences, Swansea University, , Swansea, SA2 8PP UK;6. Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, , Warrnambool, VIC, 3280 Australia |
| |
Abstract: | Populations may potentially respond to climate change in various ways including moving to new areas or alternatively staying where they are and adapting as conditions shift. Traditional laboratory and mesocosm experiments last days to weeks and thus only give a limited picture of thermal adaptation, whereas ocean warming occurring over decades allows the potential for selection of new strains better adapted to warmer conditions. Evidence for adaptation in natural systems is equivocal. We used a 50‐year time series comprising of 117 056 samples in the NE Atlantic, to quantify the abundance and distribution of two particularly important and abundant members of the ocean plankton (copepods of the genus Calanus) that play a key trophic role for fisheries. Abundance of C. finmarchicus, a cold‐water species, and C. helgolandicus, a warm‐water species, were negatively and positively related to sea surface temperature (SST) respectively. However, the abundance vs. SST relationships for neither species changed over time in a manner consistent with thermal adaptation. Accompanying the lack of evidence for thermal adaptation there has been an unabated range contraction for C. finmarchicus and range expansion for C. helgolandicus. Our evidence suggests that thermal adaptation has not mitigated the impacts of ocean warming for dramatic range changes of these key species and points to continued dramatic climate induced changes in the biology of the oceans. |
| |
Keywords: | climate change long‐term changes top down control bottom up control
NAO
sea surface temperature copepods Mesozooplankton westerly wind |
|
|