Review of cetacean biopsy techniques: Factors contributing to successful sample collection and physiological and behavioral impacts

Abstract

Biopsy techniques have been developed to collect skin and blubber samples through non-lethal methods. One sample can provide data on genetics, prey preferences, foraging ecology, contaminant loads, and physiological processes. The limited data available suggest that biopsy wounds heal quickly and that there are usually no discernable adverse health effects. Published accounts on factors contributing to the success of collecting biopsy samples and the behavioral impacts to cetaceans following biopsy sampling were standardized to permit statistical analysis. Several factors contribute to the success of acquiring samples; however, sampling rates do not differ significantly between delivery devices. Behavioral responses to biopsy sampling vary by species and other factors. The most predominant response for odontocetes is low, while low and moderate responses are equally prevalent for mysticetes. The use of retrieval lines may increase the occurrence of moderate and strong responses by mysticetes. These findings suggest that biopsy sampling is relatively benign, causing only minor and short-lived responses. However, most researchers do not report sufficient data to assess short-and long-term physiological and behavioral impacts. Finally, limited data suggest that biopsy sampling does not impact cetacean habitat use or distribution patterns. Yet these impacts are rarely investigated, so additional data are needed.

Biopsy darting of common bottlenose dolphins (Tursiops truncatus) in southern Brazil: evaluating effectiveness, short-term responses and wound healing

“…To our knowledge no long-term negative effects of biopsy sampling on the behavior or health of any cetacean species have yet been reported (e.g. Noren and Mocklin, 2012;Tezanos-Pinto and Baker, 2012), even considering those living in a polluted environment (Jefferson and Hung, 2008). Our study supports these observations.…”

“…Weinrich et al, 1991;Krützen et al, 2002;Bilgmann et al, 2007;Noren and Mocklin, 2012). Skin samples have been used in genetic and stable isotope analyses addressing questions regarding stock identity, social structure, phylogeography and trophic ecology (e.g.…”

Variation of bowhead whale progesterone concentrations across demographic groups and sample matrices

“…These samples are collected from specialized darts that retain small (~6 × 15 mm) cores of the epidermis and distal dermis (blubber) layers of the skin (reviewed by Noren & Mocklin 2012). They are the biological samples most frequently collected from freeranging cetaceans and are often obtained in numbers suitable for estimates of population-level demographic parameters.…”

Distribution, group characteristics and movements of the Critically Endangered Maui’s dolphin Cephalorhynchus hectori maui

“…However, one way to overcome this problem is to use individual identification by DNA profiling or microsatellite genotyping, which provides a permanent and unique record for every individual. Skin samples as a source of DNA can now be collected from free-ranging small cetaceans using a lightweight biopsy dart fired from a veterinary rifle with a variable pressure valve, ensuring minimum physical impact and behavioural response (Krützen et al 2002, Noren & Mocklin 2012. Systematic boat surveys were undertaken during February and March of 2 austral summers (2010 and 2011) on the west coast of New Zealand's North Island.…”