THE PURPLE SEA URCHIN

Person in charge

Sonia Ternengo

Problematic issues

Decline of naturally existing populations due to human activities and notably the impact of fishing

Reduction in urchin densities and the sizes of urchin that threaten fishing activities, the resource itself and the ecological equilibrium to which they are associated.

Objectives

Understanding the demographic changes. Management of the development cycle. Development of tools to support populations.

Description

The edible sea urchin Paracentrotus lividus is the most abundant echinoid in the Mediterranean infralittoral zone and its ecological role is important in the structuring and functioning of many benthic communities. Along the coastline, particularly that of the Mediterranean, France has a rich echinoids population of which has been fished for a significant time in history. The coastline of Corsica is no exception and sea urchins are an important fishery resource, despite the fragility due to overfishing. Corsica, through the process of sustainable economic development, is ever more seeking to preserve these fishery resources, while also aiming to maintain a community of traditional coastal fishermen. This dual initiative implies not only the understanding of resources but also the implementation of sustainable practices which do not impact upon the environmental equilibrium. In this context, the University of Corsica is developing a sustainable management programme for sea urchin fishing in Corsica. The studies objectives are to improve the knowledge of natural stock levels and monitor their evolution over time while also offering the ability to manage reproduction and development cycles of the species. The work will also focus on developing stock management tools to contribute to the maintenance of natural populations.

Steps to be taken

For its central ecological, economic and societal role, the edible sea urchin necessitates research to better understand the natural processes responsible for annual demographic changes (population structure and dynamics). Based on the results obtained, experimental population support measures will be tested to improve conservation methods, management and to augment the sea urchin resource along the Coriscan coastline to ensure production (fisheries, aquaculture). The scientific lead approach aims to inform environmental managers, fishermen and legislators with the biological data essential for any biodiversity management or natural restoration approach. The overall objective of this work is to effectively support sea urchin fishing in respect of local craft fishing practices in the region of Corsica. The project will develop on two axes:

• Environmental: with monitoring of natural populations (density, reproduction, genetics, ethology, ecotoxicology)
• Zootechnic: with the development of techniques for breeding and nurturing juvenile sea urchins, development of micro-habitats but equally a dedicated unit for refining the adult sea urchins.