New beaked whale atypical mass stranding linked to military activities around the strait of Gibraltar (2022)

Abstract

Several beaked whales were reported to have seen during the morning of the 19th of October 2002 in different points of the Gibraltar strait coastal area. Two of the 3 animals found stranded were reintroduced and one of these appeared dead stranded in the same area shortly, time later. Another beaked whale was found floating near Gibraltar several kms from that beach hours later. Therefore, it was considered with a high reliability than at least 4 Cuvier's beaked whales (Z. cavirostris) were involved in this atypical mass stranding, of which 2 dead animals were recovered for necropsy the 19th evening. The characteristics of this “massive atypical” stranding of Z. cavirostris showed body condition of the animals from good to moderate, with digested or partially digested stomach contents, with a pathology (macro and microscopic) characterized in both animals by cardiopulmonary, cardio-circulatory, renal, and nervous findings consistent with the so-called “Systemic Gas-Fat Embolic Syndrome in stranded beaked whales”. This pathology has been described in “atypical mass strandings of beaked whales” associated spatially and temporarily to naval military activities and Mid Frequency Active Sonar (MFAS) (Canary Islands, 2002, 2004, as well as in Almería, 2006, 2011 and Grecia, 2011). Even though, there were non-official information about military activities in the area. The information regarding to official military naval maneuvers and/or acoustic activities in the Gibraltar are still under investigation.