Andrew Want1, Simon Waldman2, Michael Burrows3, Joao Neiva4, Ester Serrao4, Jonathan Side2, Venki Venugopal5, Michael Bell2
1University of Hull, UK - 2Heriot Watt University, UK - 3Scottish Association for Marine Science, UK - 4Center of Marine Sciences, Portugal - 5University of Edinburgh, UK
Scottish waters are being targeted for offshore renewable energy (ORE) extraction owing to their rich wind, wave and tidal energy resources. Exposure is one of the key factors in determining intertidal community composition and structure; removing energy from the sea might be expected to impact ecological processes. At the same time, global climate change is predicted to affect exposure through increases in significant wave height and frequency of storm events. Orkney is the site of pre-commercial testing of wave and tidal devices, and licensing of large-scale offshore wind farms . As part of Before-After-Control-Impact studies of ORE deployments, surveys of 40+ rocky shore sites along this coast have identified key species and abundances, and quantified exposure-modifying topographic variables. Construction of a spectral wave model allowed comparison between baseline wave climate, and that predicted under scenarios of wave extraction and climate change. The relationship between species, topography, and exposure was examined using generalized additive modelling. Results show that expected response to changes in exposure differ between species with ‘winners’ and ‘losers’ at site level. Community responses following predicted climatic change are expected to be far greater than to industrial-scale wave energy extraction, depending on spatial scale. In combination, wave energy extraction may reduce climate-change-related increases in wave exposure on rocky shores. As a potential ‘sentinel’ species for long-term change, additional studies were made of the high-energy-associated macroalga Fucus distichus anceps. Current distribution and abundance in Orkney were compared with a 50+ year dataset, and samples were analysed for phylogenetic comparisons with similarly isolated populations in Scotland and Ireland. This species shows: strong association with steep-sloped, uncomplicated, high-exposure intertidal habitats; long-term stability at site scale; and low levels of genetic diversity between geographically distant populations. Predicting how location-specific assemblages and key species respond to changes in wave energy as a result of ORE extraction and climatic change provides a valuable monitoring tool for guiding marine resource management decisions.
Biography
Andrew is a marine ecologist pursuing a multi-faceted research approach to uncover mechanisms that underpin marine population responses to environmental changes created as the transition to decarbonise energy generation accelerates. This includes studying the interactions between epibenthic communities and natural and artificial hard substrates, such as those associated with the offshore renewable energy industry.