The oceanographic vessel Miguel Oliver departed this Tuesday from the port of Palma with 26 specialists on board to study, until August 24, the state of the populations of pelagic species in the Mediterranean, among them the anchovy —"Engraulis encrasicolus"— and the sardine —"Sardina pilchardus".
The campaign will be carried out by scientific and technical personnel from the Spanish Institute of Oceanography (IEO), in collaboration with the Ministry of Agriculture, Fisheries and Food, within the framework of the 18th edition of the Mediterranean International Acoustic Survey (Medias), a series of campaigns initiated in 2009.
According to the IEO in a statement, the central purpose is to calculate the biomass of the spawning stock of anchovy and the stock of sardine in the peninsular Mediterranean, given the high commercial importance of both species.
The fieldwork is scheduled for these dates because it coincides with the spawning months of the anchovy and, at the same time, allows for the detection of the recruitment of the sardine.
The sampling area covers the Spanish continental shelf of the Mediterranean, between 30 and 200 meters deep, from the border with France to the Strait of Gibraltar.
The acoustic survey will be conducted with a scientific echo sounder Simrad EK80, with which 111 transects will be covered and around 70 hauls will be made. These will serve to contrast the data obtained with the echo sounder and estimate the abundance and distribution of the pelagic fish community.
In parallel, the distribution of eggs and larvae of the commercially most valuable species will be analyzed, and the main oceanographic variables of the area —temperature, salinity, and fluorescence— will be characterized using hydrographic sensors.
In coordination with other IEO work integrated into the Esmares 3 project, samples of microplastics and macro-debris present in the water column will be collected, the presence and abundance of birds and marine mammals will be recorded, the trophic status of pelagic species will be studied, body fat sampling of pelagic fish will be conducted using a fat meter, and sampling of pelagic cephalopods will be carried out.
"These Medias fishing prospecting campaigns are essential for detecting interannual changes in the populations of small pelagics and contribute to an ecosystemic and more sustainable management of their fisheries," said the IEO researcher in the Balearic Islands and scientific leader of the Medias program, Magdalena Iglesias.
The Medias 2026 campaign is part of a series of acoustic surveys initiated in 2009 and coordinated with other Mediterranean countries of the European Union, such as France, Italy, Greece, Slovenia, Malta, Bulgaria, Romania, and Croatia.
The results, combined with the historical series and with different types of information from fishing activity, are integrated into the scientific evaluation groups, which from them formulate recommendations for those responsible for fisheries management.
Thus, the fishing sector, the scientific community, and public administrations have the necessary basis to move towards sustainable exploitation of the different fish populations. The campaign has co-financing from the European Union through the European Maritime and Fisheries Fund (EMFF), within the National Program for the collection, management, and use of data from the fishing sector and support for scientific advice related to the common fisheries policy.
"Acoustic surveys constitute one of the main methods for the direct study of fish populations of small pelagic species," concluded Iglesias.