Histological analysis of stranded cetaceans in the Basque Coast for the development of a cost effective sampling protocol

Abstract

[EN] Over the past decades, there has been a growing concern regarding the presence of marine mammals in the Bay of Biscay. According to law, all endangered or vulnerable species and their habitats should be analyzed. In the Basque Coast AMBAR is the organisation that has established a stranding program and network among their volunteers in collaboration with public institutions. Due to the variability that samples of stranded cetaceans may have and the lack of a specific protocol of sampling standards for the casuistry on the Golf of Biscay, results obtained from strandings are scarce as the samples´ quality is not appropriate for advance research. Thanks to AMBAR member´s help 12 individuals that got stranded during the years 2014-2016 have been analyzed. To assess an optimal sampling and processing procedure for later histopathological assessment or other scientific purposes, during this study, different histological processing have been applied. This study has lead to the development of a cost effective protocol specific for the Basque Coast and therefore can be considered the first steps for obtaining quality samples assurance. With that purpose, a histopathological case study has been evaluated. While samples taken from inner organs are more sensitive to their processing and depend on the necropsy permission from authorities since it is not still regulated, the integument together with muscle, teeth and blubber can be always sampled independently to the casuistry. For this reason and integument being one of the most abundant tissues among the samples collected during this study, different measurements on them have been done to correlate it within the health status or nutritional condition of marine mammals. Thus, a ratio among the dermal papillae height and the epidermal thickness has been calculated. Results have shown that the ratio can be an application for the integument samples in the future. This study will help in the advance of the knowledge about cetaceans in the Bay of Biscay and would permit to establish a good protocol for processing samples as law demands.