Improving knowledge on rays: Raimouest & Recoam

The CNPMEM, with the help of France Filière Pêche, is engaged in two programs of knowledge improvement regarding several species of rays, RaimOuest and Recoam in order to enhance the management of this resource and to ensure a sustainable fishery. These species are either caught as bycatch or targeted by three main types of gears: trawl, gillnet and longline. In some fishing areas, these catches represent a significant part of the fishermen revenues. These species are managed following a global TAC or are prohibited to fish, as for undulate rays or common skate. This system is considered as inadequate by both the fishermen and the scientists of the CIEM.

These programs and their expected results should lead to an improved evaluation of ray stocks, new arguments in favor of the revocation of the undulate ray status and the proposition of different, appropriate and concerted management measures.

A working group has been created by the CNPMEM to enable information exchanges on these projects and the project Raiebeca on the undulate ray carried by Aglia and the CREAA. More information is available on the websites of these two structures. This working group gathered twice a year until the end of 2014.

These programs include ray tagging. You can download the information poster and the document explaining the process to follow in case you find a tagged ray. DO NOT FORGET TO MENTION IT. In addition, it is important to identify rays correctly in log books and fishing forms in order to improve the tracking of catches. Identification guides and posters are available at the CNPMEM.

The program RaimOuest

This project was carried by the CRPMEM Basse-Normandie, in partnership with the SMEL, Ifremer and the APECS (Association for the study and the preservation of rays). It started in July 2012 and ended in June 2014. It served the purpose of collecting socioeconomic data in order to measure the impact of landing prohibition of the undulate ray in order to characterize the ray fishery and finally, to enrich and analyze the available marine data so that ray stocks may be characterized (from data of the Obsmer program and boarding).

Main results:

In the Normano-Breton Gulf, about 180 vessels are concerned by ray fishery which represents 60% of the total fleet. Before the landing prohibition of undulate ray, enforced in 2010, the total ray fishing part in the revenues fluctuated between 10 and 30 %.

The many trawl and gillnet samples performed within Obsmer (national program enforced by the ministry for on-board observers on fishing vessels) for the past 10 years in the Channel – North Sea area confirm that the undulate ray stock is located near the Normano-Breton Gulf. In 2012, the quantities of undulate rays caught by trawl in the Western Channel (CIEM zone VIIE) are estimated at 750 tons which reveal an indisputable abundance of that species.

The program Recoam

The project is supported by the APECS. It aims at collecting data in order to improve the knowledge on the biology (for example the size at sexual maturity), the horizontal motion and the genetic structure among the population of 5 types of rays (undulate ray, blonde ray, spotted ray, owl ray and thornback ray). It provides the chartering of professional vessels to perform the tagging and biological sample (during fall and spring). The goal is to tag at least 2.500 rays. Embarkations will also be performed within the RaimOuest and Raiebeca programs to collect information and achieve tagging. The APECS is also in charge of the operation of communication to ensure feedback on recaptured fishes. The project ended in 2014.

Main results:

Over 2.300 individuals (figures include tagging achieved within the project Raiebeca) have been tagged in the Pertuis Charentais / Gironde Estuaries and over 1.400 in the Normano-Breton Gulf.

Tags highlighted that the distance between the tagging zone and the recapture zone of undulate rays is low in the two areas concerned by the study.

The length to which 50% of the male individuals reached the sexual maturity (L50), useful information when reflections are conducted on the implementation of minimum or maximum capture sizes, have been calculated in The Channel and the Atlantic Ocean.

The analysis of genetic samples has started in 2014. For your information, the Obsmer observers collect tissues of undulate rays that will be used during this study.

With financial support of France Filière Pêche

Mis à jour le 27 March 2015