Pathology and causes of death of cetaceans stranded in Canary islands (1999-2005)

Abstract

In thc Canary lslands wmcrs, 28 cetacean species have bcen identificd of which 24 specics have been found stranded. During a 6 year-period (1999- 2005) 233 stranded whnles and dolphin.􀉽 of 19 different species were recovered for scienti!ic studies. Using a systematic standardiz.ed necropsy protocol, 138/233 $lraJ\ded l:emceans were suhjected to a complete or partía! nccmpsy. Of these, 71/!38 (51 .45%) earcasscs wcrc in a very fresh or fresh status, 28/138 (20.29%) in moderute auloly¡;is and 39/138 (28.22%) in advanced autolysis. Pathological studies were conducted by the Institute of Animal Hea!th (Univcrsity of Las Palmos de Gran Canaria) in order to identify lesions aod to determine a morphological diagnosis, identify aetiologica! agents, ami, u!tünately, to reach mi etiological diagnosis. AF, a result of these proces􀏺r,;, cause(s) of deruh (defincd as pathological entities) were identified wherever possible. From a total of 233 eetaccans stnmded in the Canary li;Jands (1999-2005), in 59,23% nf the cases a morphologica! diagnosis was done, in 56,22% an etiological diagnosis could be established and, finally, we were ab!e to classify 51,07% wit11in natural or anthropogcnic pathological entities. EtiO-pathologically, 62,32% of the 138 studied cetaceans were diagnosed as nal\lral (i.e. non-anthropogenie) pathological entities that iocluded infectious diseases, neonatal pathology, intra- and interspecifie interactions ami typieal mass strandings. Anothcr 33,33% of cases were diagnosed as anthropogenie emities including fishing intcraciion {by-emch), atypical mass-stranding linked to naval exen:is,:;o¡, ship eo!lisions, and other anlhropogenic-related pa!hology. A cause of death eould not be ascribed in only 4,35% of the 138 animals cxamined.