Preliminary results of the PELACUS0316 survey: estimates of sardine, anchovy and horse mackerel abundance and biomass in Galicia and Cantabrian waters

PELACUS 0316 has been carried out between 13th March and 16th April, covering the north Spanish continental self between the Miño river (Spanish/Portuguese border) and the Bidasoa one (Spanish/French border). Unexpectedly, weather and oceanographic conditions found were those of the winter time rather than the incipient spring ones. Consecutive deep W/NW storm fronts have affected the survey plan; five days were lost due to the bad weather conditions and even during part of the survey either strong south wind (up to 45 knots) or a persistent swell of about 2-4 m height have also made problems to achieve clean echograms (i.e. without bubbles) and good performance at the fishing station. These conditions might have been also affected the availability of the fish. This seems clearer in the southern part (IXaN), where a stronger winter poleward current led the continental self almost empty of plankton and with a very scarce concentration of fish. Abundance of the main pelagic fish species was lower than that of the previous year. For sardine the abundance was very low, practically below of an acceptable threshold for an acoustic assessment. Only the presence of a very thick school with acoustic and morphological characteristics being compatibles to those of sardine, thus being possible sardine but not ground truthed. In total the assessed biomass was very low, and excluding this school only 3 thousand tons were estimated, the lowest record in the time series (13 thousand tons including this school but still at a very low level) Horse mackerel showed also an important decrease while anchovy has been mainly detected at the inner part of the Bay of Biscay, although as it was observed for sardine, the presence of thick schools in the western part, presumably being anchovy, had an important impact in the final assessment