Research on the biology and fishery of North Sea shrimp CRANgon crangon as basis for an efficient self-management (CRANMAN)

Background and Objective

The brown shrimp fishery is an important fishery in Germany, which is not managed by the European Union. The scientific assessment for the non-regulation of the shrimp fishery is based on research from the 1970s. Recent research has called into question this assessment, and therefore the need for management of shrimp fisheries is being re-discussed. The situation on the shrimp marketing side has also changed as wholesalers increasingly insist on certification of fisheries. However, a central prerequisite for certification is scientific stock assessment and resulting management recommendations for the fishery.

Due to the short lifespan of North Sea brown shrimp (Crangon crangon), a monthly monitoring of the stock must take place and regulatory measures should be taken immediately in the ongoing season. This is most likely to be done by the fisheries themselves, which is why the first step was self-management through fisheries. The management plan essentially includes a fishing ban at times of low stock levels and a successive increase in mesh size. The CranMan project aims to scientifically investigate and improve the effectiveness and efficiency of fisheries self-management.

Approach

1. Analysis and standardization of fishing effort and distribution from log books and VMS data
2. Monitoring and improving the Harvest Control Rule (HCR)
3. Investigations on the density-dependent growth limitation of North Sea shrimp
4. Monitoring bycatch of non-target species and developing measures to further reduce it
5. Development of concepts for a standardized survey with commercial cutters
6. Evaluation of the self-management and comparison with previous experience and scientific research on successful self-management concepts
7. Interviewing fishermen about the acceptance of different management measures and management expectations