General Fisheries Commission for the Mediterranean - GFCM

Research Programme
on blue crabs

Two large non-indigenous species of blue crab (the American blue crab, [Callinectes sapidus] and the blue swimming crab, [Portunus segnis]) have been present in the Mediterranean since at least the first half of the 20th century.

Both species have a high reproductive capacity and potential to expand their range. They are known for problematic interactions with traditional types of fishing gear, such as gillnets or trammel nets, in which they can become entangled, harming both the catch and the nets themselves. For this reason, their gradual spread across the Mediterranean initially presented a cause for concern among both fishers and conservation specialists. However, since the blue crabs are large and also tasty and nutritious, fishers began to develop dedicated gear to catch them and found markets at which to sell them. Stakeholders now agree that this approach is the only way to both control the blue crabs’ expansion and create new market opportunities for fishers.

In recent years, the populations of both species have significantly increased both in number and in geographical range, and there is a clear need for a common management strategy to deal with them. To this end, the GFCM issued Recommendation GFCM/42/2018/7 on the implementation of a regional research programme on blue crab in the Mediterranean Sea, in order to properly evaluate their population status and maintain sustainable fisheries.  

Objectives:

The main objective of this research programme is to set up a coordinated science-based framework for the sustainable management of blue crab fisheries, taking into account both economic and environmental objectives.

Area of implementation

Focus Countries:

Algeria, Croatia, Cyprus, Egypt, Greece, Italy, Montenegro, Morocco, Slovenia, Spain, Tunisia, Türkiye

Duration

2022–2026

Activities

The research programme has six specific objectives, each corresponding to one work package (WP): 

WP 1. Collect as much information as possible on the biological and ecological characteristics of the two species of blue crabs in order to support responsible fisheries management. 

WP 2. Collect fisheries-independent data to provide valuable additional information on catch composition and the overall affected faunistic community.    

WP 3. Collect fisheries-dependent data on Mediterranean blue crabs to provide a foundation for an effective management structure and process. 

WP 4. Establish an ad hoc framework for blue crab stock assessment, considering both the habitats of the crabs and the particular characteristics of the fisheries.

WP 5. Understand both the technical/technological and socioeconomic aspects of blue crab fisheries. 

WP 6. Develop adaptive management measures at the local, national and regional levels to keep blue crab populations at low levels. 

Learn more about the GFCM management-oriented research.