Abstract
There is considerable uncertainly regarding the influence of climate change on structure of marine fish assemblages, yet increasing evidence suggests that maintenance of diversity across trophic levels is key to safeguarding ecosystem function. We propose to investigate climatic influence on spatial and temporal structure of the northeast Atlantic marine demersal fish assemblage. Using collated data from UK government survey trawls, we aim to 1) investigate whether there is a northeast Atlantic signature of diversity change linked to temporal climatic variability, and whether temporal changes in community composition have been of the same magnitude across the region. 2) test if individual species show similar abundance trends throughout their geographic ranges, and identify ecological and life-history species traits linked to temporal changes of abundance, including body size, growth rates and trophic level and 3) test the reliability of climate-envelope predictions of future species distributions and abundances, and compare these to predictions made using models incorporating density-dependent habitat choice. Our goal is to identify the scales for patterns of change in species abundance and to quantify uncertainties underpinning predictions of ecological change during forecasted 2 to 4 C rises in mean annual sea surface temperature over the next 100 years.