Contribution to the Knowledge of Cetacean Strandings in Chile Between Years 2015 and 2020

Abstract

Strandings are one of the most worrying issues in relation to the conservation of cetacean species, and in the case of Chile, due to its geography and large extension of the coastline, monitoring and access to these events is difficult, making their study more complex. Chile has a shortage of specialized scientific forensic research facilities for cetacean; however, for this study it was able to collect data recorded from official institutions and sporadic scientific biological sampling oriented to investigate the causes of death or stranding. According to the Chilean government official database, we described that the main causes of unusual mortality events (UME) and mass strandings from year 2015 and 2016 were acute poisoning by biotoxin and trauma to the auditory complex, respectively, while individual strandings would have their causes in anthropogenic activities such as entanglements in fishing an aquaculture gear and collisions with vessels. The predominant species in mass strandings was the sei whale (Balaenoptera borealis). The geographical area of greatest prominence in mass strandings was the Aysén Region in the Central Patagonia of Chile, while the species mostly involved in individual strandings along the south-central, central, and northern coast of Chile was the small porpoise (Phocoena spinipinnis). The most common gross pathological findings were advance decay of the carcasses and nonspecific wounds of different nature, difficult to associate with possible causes of death without further histopathological studies.