Prof. Michael Burrows1, Dr Tim Szewczyk1, Dr Dan Smale2, Prof Pippa Moore3
1Scottish Association for Marine Science, Oban, United Kingdom, 2Marine Biological Association, Plymouth, United Kingdom, 3Newcastle University, Newcastle, United Kingdom
The dynamic and inaccessible nature of kelp habitats make mapping and quantifying kelp distributions challenging in many regions and for many species. We used a statistical modelling approach using categorical abundance data, including defined absences, to predict 200m-scale habitat suitability for five common kelp species across shallow coastal habitats off the UK and Ireland. Depth and chlorophyll a, proxy for nutrients and light attenuation, emerged as the major determinants of local presence, with wave exposure separating the species. Temperature was limiting only in the far south of the modelled region. Total biomass and primary production were estimated for Laminaria hyperborea and Saccharina latissima using methods based on predicted habitat suitability and relating experimentally measured rates of growth and recolonisation to that biomass. Total habitat suitable for Laminaria hyperborea was estimated as 2550 km2 using summed areas of predicted presence and 2150 km2 using summed area weighted by the likelihood of the species being >1 plant per m2, with latter giving a biomass of 10.8 Mt fresh weight (0.67Mt C). Saccharina latissima was the next most extensive and abundant kelp (1330 km2 , >0 m2, 500 km2, >1m-2) with an estimated total biomass of 0.3 Mt (0.019 Mt C). Production to biomass ratios for Laminaria hyperborea and Saccharina latissima were estimated from previous studies to be 0.9 and 2.3 respectively, giving production estimates of 0.43 MtC/yr and 0.031 MtC/yr. Model estimates like these contribute to monitoring, management and conservation of kelp forests, and the understanding of kelp’s role in ecosystem functioning.
Presentation Slides – Michael Burrows
Biography:
Mike Burrows is a coastal marine ecologist looking at effects of climate change on communities and populations of benthic species.
