Phenological trends and trophic mismatch across multiple levels of a North Sea pelagic food web

Marine Ecology Progress Series

Stephen J. Thackeray¹  David A. Elston¹  Mark Newell¹  Sarah Wanless¹  David Johns¹  Adam Butler¹  Francis Daunt¹  Morten Frederiksen¹  Sarah Burthe¹ 

关键词: Timing of breeding;    Climate change;    Prey size;    Ammodytes marinus;    Winter NAO;    Long-term studies;    Zooplankton;    Phytoplankton;   

DOI  :  10.3354/meps09520

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Differential phenological responses to climate among species are predicted to disrupt trophic interactions, but datasets to evaluate this are scarce. We compared phenological trends for species from 4 levels of a North Sea food web over 24 yr when sea surface temperature (SST) increased significantly. We found little consistency in phenological trends between adjacent trophic levels, no significant relationships with SST, and no significant pairwise correlations between predator and prey phenologies, suggesting that trophic mismatching is occurring. Finer resolution data on timing of peak energy demand (mid-chick-rearing) for 5 seabird species at a major North Sea colony were compared to modelled daily changes in length of 0-group (young of the year) lesser sandeels Ammodytes marinus. The date at which sandeels reached a given threshold length became significantly later during the study. Although the phenology of all the species except shags also became later, these changes were insufficient to keep pace with sandeel length, and thus mean length (and energy value) of 0-group sandeels at mid-chick-rearing showed net declines. The magnitude of declines in energy value varied among the seabirds, being more marked in species showing no phenological response (shag, 4.80 kJ) and in later breeding species feeding on larger sandeels (kittiwake, 2.46 kJ) where, due to the relationship between sandeel length and energy value being non-linear, small reductions in length result in relatively large reductions in energy. However, despite the decline in energy value of 0-group sandeels during chick-rearing, there was no evidence of any adverse effect on breeding success for any of the seabird species. Trophic mismatch appears to be prevalent within the North Sea pelagic food web, suggesting that ecosystem functioning may be disrupted.

【 授权许可】

Unknown