Effects of cold winters and climate on the temporal variability of an epibenthic community in the German Bight

Climate Research

Ingrid Kröncke¹  Siegfried Ehrich¹  Hermann Neumann¹ 

关键词: Epifauna;    North Sea;    Temperature;    Climate;    NAOI;    Cold winter;    Mild winter;    Succession;   

DOI  :  10.3354/cr00769

来源: Inter-Research Science Publishing

【 摘 要 】

ABSTRACT: Benthic epifauna was sampled in an area of 10 × 10 nautical miles in the German Bight. Samples were collected in January and July/August from 1998 to 2007 with a standard 2 m beam trawl. The epibenthic communities were severely affected by the cold winter in 1995–1996, which also resulted in high abundance and biomass of the opportunistic brittle star Ophiura albida, in connection with low diversity observed at the beginning of our study period. In the following years winter bottom temperature increased simultaneously with the decrease of O. albida and the increase in abundance and biomass of other species. It appears that these changes were caused by trophic interactions as well as mild winters, which resulted in lower mortality, higher reproduction and higher food supply for benthic fauna due to enhanced primary production. Additionally diversity increased and species such as Astropecten irregularis, Corystes cassivelaunus, Crangon crangon and Crangon allmanni revealed distinct seasonal patterns caused by migration, mortality and reproduction cycles. The changes in community structure are discussed in relation to the general warming trend of the North Sea, which is linked to a phase of continuously increasing North Atlantic Oscillation Index (NAOI) since the late 1980s. We found evidence that climatic variability influenced recruitment success, mortality and migration patterns of epifaunal species.

【 授权许可】

Unknown