Estudio de viabilidad del uso de técnicas acústicas activas para la detección y caracterización de Pinna nobiliis y Pinna rudis en la zona de Calpe

Abstract

In the present work we show the preliminary results of the use of a side-scan sonar for the monitoring of seagrass Posidonia oceanica and the fan mussel Pinna nobilis in the marine area around the ¿Penyal d¿Ifac¿ in Calpe (Alicante), Spain. Both species are intimately linked and are endemic and emblematic to the Mediterranean Sea. For P. oceanica, four meadows were studied in different conservation states and at various depths. Direct measures of density and cover were taken to look for a correlation with the acoustic data. For P. nobilis, and due to the recent mass mortality event (MME), empty shells were used as a first step in the acoustic detection. The shells were placed in two different environments, bare sand, which will serve to learn about the acoustic signal of the shells, and P. oceanica, their main habitat. The results show a correlation between the acoustic results and direct measures of P. oceanica. P. nobilis shells were clearly detected in bare sand. However, the shells were barely detected, if so, in P. oceanica.