For its 13th edition, the annual operation « Species that matter » took place on September 23rd and 24th. It was held in the waters between Île Verte at La Ciotat and the Frioul archipelago in Marseille, in the marine heart of the Calanques National Park set up 4 years ago. This operation was organized by the Departmental Environment and Underwater Biology Commission of Bouches-du-Rhône and the Regional Environment Commission Provence Alpes of the FFESSM in partnership with the Calanques National Park and with the support of the Grouper Study Group (GEM), from the Bleu Coast Marine Park, from the Mediterranean Institute of Oceanography (MIO) and thePaul Ricard Oceanographic Institute. Over the course of the two days of action, more than 200 scuba divers or free divers, all passionate volunteers, took to the water to conduct 319 dives across 33 sites scrutinized in great detail.
This event is the first French participatory science operation in terms of number of participants, sustainability, and also in terms of the area studied. Indeed, « the marine territory of the Calanques National Park is 10 times larger than that of Port-Cros, » as explained by Mr. Jean Cabaret, president of the Regional Environment and Underwater Biology Commission Provence Alpes, board member of the Calanques National Park and member of the Grouper Study Group.The populations of groupers have doubled!The information to be processed being very important, more precise results will be published soon concerning mainly the following three protected species: Mediterranean dusky grouper (Epinephelus marginatus), brown meagre (Sciaena umbra) and fan mussel (Pinna nobilis). But the first lesson from these two days of counting already reveals a doubling of the number of Mediterranean dusky groupers. Last year their number was 150, this year more than 300 individuals were identified, with a fairly homogeneous size distribution (from about 20 cm to 1 m), which is very favorable for the reproduction of the species. Indeed, the grouper is a singular fish that changes sex during its life, the small individuals (the youngest) are females and the largest individuals (thus the oldest) are males, if there are not enough small individuals reproduction cannot occur. In a few years, with the maintenance of the 10-year moratorium (valid until 2024) prohibiting the fishing of this fish, « it is very possible that these numbers will increase and exceed the number of groupers present in the Port-Cros National Park (currently 800) », notes Jean Cabaret. As for the brown meagres, their growth and distribution are more uncertain, analysis of the results will provide more accuracy. And regarding the fan mussels, the results seem satisfactory.
The cover image is by Frédéric Fedorowsky from the Departmental Environment and Underwater Biology Commission of Bouches-du-Rhône.
Morgane CONSTANTIN
Save
Save