Identifying juvenile fish habitats for sustainable fisheries

Sampling at a sandy beach in Cornwall: even very shallow areas can be important habitats for a range of different flatfish species

Title: Identifying juvenile fish habitats for sustainable fisheries

Partners: Devon and Severn IFCA

University of Plymouth staff: Dr Ben Ciotti, Anna Persson

This research focuses on identifying the areas and features of our coastline that are required by the young fish that go on to support our commercial fisheries. During juvenile life stages, most commercially exploited species rely on shallow, inshore waters, but such areas are often heavily impacted by humans. Knowing where the most important juvenile habitats are located allows conservation priorities to be set with consideration to the needs of fisheries management.

To identify key nursery habitats, The University of Plymouth is working with the Inshore Fisheries Conservation Authority to undertake comprehensive surveys of the fish fauna in habitats throughout the southwest, from the tip of Cornwall to the Severn Estuary. Basic measurements of juvenile fish densities, sizes and diets are being combined with molecular indices of physiological condition to understand not only how many fish are using an area, but also how well they are feeding and growing. This information allows us to create maps of habitat quality and identify how variation in habitat quality is related to environmental variables and coastal features.

“The juvenile life stage is a really important focus of fisheries conservation. Processes occurring at these young ages often has a tremendous influence on stock sizes, yet this is also the time when many fish become are most exposed to human activities. Identifying juvenile fish habitat needs is the first step in safeguarding the habitats necessary to support sustainable fisheries.”

Dr Ben Ciotti

“Fisheries management is striving to adopt an ecosystem approach, which requires an understanding of the whole life-cycle of commercial species, and the habitats they rely on at each stage. Similarly we need to understand the broad range of human impacts on those species either directly removing fish from the ecosystem or indirectly affecting them through habitat alteration. Commercial and recreational fishing, coastal development, aggregate dredging, renewable energy instillations, water abstraction for nuclear power stations and climate change all have the potential to impact fish communities. Our work with the University of Plymouth is helping to provide this crucial evidence base for regulators.”

Libby West