Miss Nora Salland1, Miss Catherine Wilding2, Dr Antony Jensen3, Dr Dan Smale2
1Marine Biological Association & University of Southampton, Plymouth & Southampton, United Kingdom, 2Marine Biological Association, Plymouth, United Kingdom, 3School of Ocean and Earth Sciences, University of Southampton, Southampton, United Kingdom
Ocean warming is driving a redistribution of species at a global scale. Biogeographic transition zones, such as the Boreal-Lusitanian mixing region (BLMR) in the northeast Atlantic, may be hotspots for species range shifts, as both warm and cold adapted species may be found towards contrasting range edges. While anecdotal evidence suggests some distributional shifts have occurred, the evidence base remains poor.
We re-surveyed historical kelp sites (1950-2012) in intertidal and shallow subtidal habitats in the BLMR in southwest UK to test the prediction that warm-adapted species have increased in abundance/extent in response to recent warming whereas, conversely, cold-adapted species have declined.
Survey data confirmed the expected decline of some cold-adapted kelps (i.e. ocean warming ‘losers’, such as Alaria esculenta and Saccharina latissima), although populations of other species were stable over time (Laminaria digitata). While the cold-adapted Boreal kelp L. hyperborea still dominates kelp forests across the region, some warm-adapted Lusitanian species (i.e. ocean warming ‘winners’ Saccorhiza polyschides and L. ochroleuca) have seemingly proliferated, as has an invasive species Undaria pinnatifida.
Continued warming will likely lead to further shifts in distribution and abundance of canopy formers, with consequent changes to broader kelp forest composition. As ecological functions and traits differ between kelp species, in particular between the ocean warming ‘winners’ and ‘losers’, wider changes in ecosystem service provision and ecological resilience may ensue.
Presentation Slides – Nora Salland
Biography:
I am a marine ecologist and postgraduate researcher with keen interest in kelp forest community structure. My research is focused on the effects of climate change stressors (especially ocean warming) on foundation species such as kelps and their associated flora and fauna community. I am exploring resulting physiological responses of kelp to changing conditions on both individuals and population based levels, as well as the impacts on the entire ecosystems. Bachelor and Master in Rostock (Germany), Master thesis in Chile on Macrocystis’ warming tolerance, started PhD in 2019 with Dan Smale at the MBA in Plymouth (thesis submission winter 2023).
