Miss Jen Lewis1,3, Dr Audrey Darnaude2, Dr Regan Early1, Dr Ewan Hunter3, Dr Frank van Veen1
1University Of Exeter, Penryn, United Kingdom, 2Center for MARine Biodiversity, Exploitation & Conservation, Montpellier, France, 3Centre for Environment Fisheries and Aquaculture Science, , UK
Understanding the dynamics of range expansion is necessary and important for the successful management of fish populations. The gilthead seabream Sparus aurata is a high-value fish for commercial and recreational fishers, and the rise of sea surface water temperature is thought to be responsible for an apparent range expansion into the English Channel and the Celtic Sea. With further climate warming, this species is expected to further expand its range northwards.
Currently little is known about the northernmost population, but adult fish are being caught more frequently in the spring/summer months, and juveniles have been observed in recent years. Current climate trends suggest that further northward expansion in the coming decades is likely.
S. aurata spawns offshore during the winter in aggregations, and have a long pelagic egg and larval stage that facilitates high dispersal capability. We applied different techniques (including otolith microchemistry, stable isotope and particle tracking) to investigate whether multiple spawning events were contributing to cohorts caught in the UK and whether there was any evidence for localised spawning populations in this range expanding species.
A greater understanding of this target fish will benefit sea-anglers and fishers, the coastal tourism sector and conservationists managing the long term sustainability of inshore fisheries.
Jen Lewis is a PhD researcher at the University of Exeter (UK), and the Centre for Fisheries and Aquaculture Science (CEFAS). She is interested in the effects of anthropogenic climate change on marine species ecology and distributions, using gilthead seabream Sparus aurata as a model species.