'We need to better understand habitats off the Isles of Scilly', say experts
The University of Plymouth has been looking at human impacts and also areas left where humans haven't intervened in a decade
The first study of its kind has been carried out looking at the habitats and animals off the Isles of Scilly.
Professor Emma Sheehan, from the University of Plymouth, looked into human impacts and studied areas which haven't been touched in 10 years by humans - where wildlife has thrived.
The research used a range of techniques to monitor the ocean sediments around the archipelago and to explore the diversity of species living within them.
Working with local fishers and conservation managers, the study team carried out a series of towed and baited video surveys at 10 locations outside of any existing Marine Protected Areas (MPAs).
Those surveys uncovered an array of different sediment habitats – from sandy bedforms to boulders and cobbles over sand – located at depths of up to 90 metres below the ocean surface.
The habitats were found to support more than 90 species of seabed animals, ranging from corals and sponges to varieties of worms, sharks, rays and starfish.
Many upright species on the seabed, such as sponges, could provide refuge for other species and increase habitat sensitivity while these habitats can create nursery and feeding areas for species of commercial and conservation importance.
However, further analysis has shown this diversity in sediment habitats is not fully captured by habitat classifications within the European Nature Information System (EUNIS). Marine EUNIS classifications are designed to describe habitats and the species living in particular parts of the ocean. They can be used to inform decisions and policies on human activities for conservation management.
The new findings have led the study team to suggest that classifications for sediment habitats around the UK are potentially being based on shifted baselines, information based on how a habitat can appear following decades of human activities, rather than the best-case scenario for its composition and health.
The new study has been published in the Journal of Applied Ecology and is part of an ongoing project by researchers from the University’s Centre for Marine Biology and Conservation Science (CMACS).
Its lead author is PhD researcher Rebecca Turley and she is part of a research team led by Professor of Marine Ecology Emma Sheehan, one of the UK’s leading experts in the assessment of marine conservation zones and Marine Protected Areas (MPAs).
Rebecca Turley said: “Many of the sediment habitats around the Isles of Scilly have not been trawled or dredged for over a decade. So, it provides a really good example of what a recovering seabed can look like. Our study has filled significant gaps in knowledge about the diverse species that can thrive in sediment habitats unimpacted by bottom-towed fishing gear for more than 10 years. However, where shifting baselines affect habitat classifications, they will need updating to ensure that marine habitats are appropriately protected in the future.”
Based on their findings, the researchers have made three recommendations which they believe could improve future decisions concerns the Isles of Scilly and other UK locations.
They are:
1) That marine management shifts away from a reliance on rigid EUNIS classification frameworks, and that classifications and sensitivity assessments are reviewed to capture new evidence, or we risk MPA integrity and efficacy;
2) That robust monitoring – despite the fact it can be costly and time consuming – is put in place to determine ecological baselines and recovery;
3) That MPAs should be managed based on the habitats and species found within the whole site, rather than focusing on individual habitat features, as a means to better protect marine ecosystems.
Professor Sheehan, whose work has influenced the designation and management of MPAs at various sites around the UK coastline, added: “The new understanding of sediment habitats confirms that current marine management policies, such as EUNIS classifications, reflect shifted baselines.
"For MPAs to be effective tools for marine conservation, we need to address any uncertainties in existing habitat classifications and sensitivity assessments, amend marine habitat condition targets and update spatial measures in conservation planning. Through our recommendations, we could move closer to an ecosystem approach that properly enhances the recovery and conservation of both habitats and species.”