Bio: I am a community ecologist with broad research interests, but a particular focus on how global environmental change is influencing the structure and functioning of coastal marine ecosystems. Our team at the MBA employs a range of approaches, including field surveys, laboratory and mesocosm experiments and modelling techniques, to better understand patterns and drivers of marine biodiversity in rapidly changing world. I have studied coastal habitats such as kelp forests and fucoid beds for over 20 years across Australia, South America, Antarctica and Europe. Our research has demonstrated (i) the importance of kelps as habitat-forming species and determinants of local biodiversity, (ii) the responses of kelp forest communities to both long-term gradual climate change and extreme climatic events, and (iii) patterns and drivers of kelp forest structure and productivity in the UK. More recently, we have worked with local industry to support the sustainable development of the UK seaweed sector, principally by quantifying the ecological impacts and ecosystem service benefits of kelp farming. I also co-lead an international working group on marine heatwaves, which are emerging as important drivers of marine ecosystem change and are likely to intensity under anthropogenic climate change.

Talk title: Kelp forest dynamics in a rapidly warming ocean

Abstract:  Kelp forests dominate shallow rocky habitats across much of the world’s temperate and polar coastlines. As foundation species, kelps support high levels of primary productivity, magnified secondary productivity, and support highly diverse communities. However, the abundance, performance and distribution of many kelp species are impacted by global change factors, including ocean warming, increased herbivory and decreased coastal water quality. Due to the often inaccessible nature of kelp forests, however, fundamental knowledge gaps pertaining to their structure and functioning is lacking in many regions, hindering management and conservation efforts. Here, I draw on evidence from a biogeographic transition zone in the northeast Atlantic to highlight both stability and shifts in kelp populations and communities, in a region faced with rapid ocean warming and intensifying marine heatwaves. Using historical data (up to ~80 years old) combined with contemporary surveys, I show that range centre populations of the dominant kelp Laminaria hyperborea have remained largely stable through time, whereas populations towards the trailing range edge have exhibited some declines. Moreover, the abundances of other kelp species found toward their range edges – in particular Saccharina latissima, Alaria esculenta and Laminaria ochroleuca – have responded in line with recent warming trends. The wider consequences of range shifts and altered abundances for ecosystem structure and functioning have begun to be explored through manipulative experiments and targeted surveys, while approaches to management and restoration during a period of rapid change are under development. While the paradigm of kelp forests as highly dynamic ecosystems does not always hold true, ocean warming and other anthropogenic stressors now threaten the continued persistence and stability of these ecosystems in many regions.