Ecosystem Based Management
Our work with the Isle of Man government is based on an ecosystem based approach to fisheries management. We recognise that the key target species with Isle of Man territorial waters do not exist in isolation and that a holistic view of the marine ecosystem in which these target species live is required to enable a healthy sustainable fishery. In this sense, while a key focus of our work is understanding trends in stock status and fishing effort, we also undertake fundamental work to understand the biology, behaviour, ecology of key taxa, the benthic habitats in which they live, and the way management can have a positive impact on the marine environment.
Examples of this approach include:
Relative benthic status: The impact of demersal fishing gear on benthic habitats is well known. In some habitats, negative effects on the physical structure and biological diversity/ complexity can have important consequences for recruitment of important target species. Our recommendations for sustainable management of scallops take account of the potential impact of fishing on the seabed. To this end, we are progressing work to examine the spatial footprint of scallop fishing and its impact on the relative benthic status of the seabed across within Isle of Man territorial waters.
Closed areas: Closed area research within Isle of Man territorial waters extends back to the establishment of the Port Erin closed area in 1989. Bangor University has continued to use closed areas as both practical management and research tools. Recent work for example at the East Douglas Research Area (EDGERA) has shown a 2.3- and 1.8-fold increase in queen and king scallop densities respectively over the last 5 years alongside recovery of the benthic habitat, which is likely a contributory factor to facilitating recruitment. A large proportion of the 0-3 nm region of the Isle of Man territorial waters is currently protected from mobile fishing gears through the establishment of a network of Marine Nature Reserves. We work closely with DEFA to progress the development of a management plan for these important benthic habitats.
Crustacean tagging: Brown crab and lobster are known to move significant distances. Such movement has implications for monitoring of stock status and for management of stock among jurisdictions and in relation to closed areas. Our preliminary work in understanding movement of brown crab and lobster shows there is a significant knowledge gap, but also suggests increased understanding will aid our approach to spatial management. Over the period 2022-2025 we plan to work closely with industry and with other jurisdictions in the Irish to implement a mark- recapture programme.
Benthic habitat mapping: Understanding the physical and biological nature of the seabed is key to effective management. The distribution of benthic habitats in the Manx territorial sea was determined through a detailed habitat survey by Bangor University in 2008. The survey identified 40 distinct communities, 20 biotopes, and 13 broader habitats in Manx waters. More recently we have undertaken high resolution video surveys of the benthic habitats and communities of all the main closed areas. These were used to generate biotope maps and species lists of Baie ny Carrickey, Laxey Bay, Niarbyl Bay, Ramsey Bay, Douglas Bay and Port Erin Bay Marine Nature Reserves.
Blue carbon: The assessment of blue carbon resources within Isle of Man territorial waters and the development of action plans to maintain and enhance sequestration is an important part of the Isle of Man’s Climate Change programme. Determination of the role that demersal fishing plays in the blue carbon budget is a key focus. We are providing essential data on benthic habitat within Isle of Man territorial waters, mapping the intensity of fishing activities and undertaking scoping reviews for diversification into fishing practices which may reduce disturbance of key blue carbon resources.