Preliminary Evaluation of Potential Impacts Associated with Small Cetacean Remote Biopsy Sampling by Controlled Testing on Stranded Common Bottlenose Dolphins (Tursiops truncatus)

Casey Brechtel,Errol I. Ronje

doi:10.3390/jzbg2040039

Casey Brechtel, Errol I. Ronje

Open Access

https://doi.org/10.3390/jzbg2040039

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Abstract

To explore the potential macroscopic tissue effects of select remote biopsy tools to common bottlenose dolphins (Tursiops truncatus), carcasses were darted and their traumatic effects on the anatomy in target and non-target areas of the body were described. In total, 87 samples were collected (target area, n = 19; non-target area, n = 68) within standardized grid partitions from five carcasses of sub-adult to adult age classes with a range of body condition scores. We broadly classified impacts penetrating completely through the blubber into muscle or deeper internal tissues as over-penetrations (n = 51/87, 59%). For samples collected in the defined target area, there was a low number of over-penetrations (n = 5/51; 10%). However, for samples collected in the defined, non-target areas, a much higher number of over-penetrations occurred (n = 45/51 88%). A visual examination of some samples indicated that sample length and appearance may not be reliable guides to assess the penetration depth of the wounds. These preliminary results suggest samples collected in non-targeted areas could pose much higher risk to the individual. We encourage other researchers considering the use of remote biopsy tools to conduct similar assessments prior to field sampling to better understand the potential consequences of misplaced samples with a view towards continually improving remote biopsy tools and techniques for the benefit of cetacean welfare.

Highlights

Remote biopsy darting has been an important data collection tool in the repertoire of marine mammal scientists [1]
To prevent penetration into the muscle tissue underlying the subdermal fascia, each remote biopsy dart is designed with a rigid backstop that assists with dart rebound on impact, at which point the obtained sample can be collected for processing
For small cetaceans such as common bottlenose dolphins, the target area on the body described by some researchers for sample collection is high on the lateral side of the animal, just below the dorsal fin [7,8,9,10] and above the transverse processes of the vertebrae, where substantial epaxial muscles lie underneath the subdermal fascial plane [11]

Summary

Introduction

Remote biopsy darting has been an important data collection tool in the repertoire of marine mammal scientists [1]. To prevent penetration into the muscle tissue underlying the subdermal fascia, each remote biopsy dart is designed with a rigid backstop that assists with dart rebound on impact, at which point the obtained sample can be collected for processing. For small cetaceans such as common bottlenose dolphins, the target area on the body described by some researchers for sample collection is high on the lateral side of the animal, just below the dorsal fin [7,8,9,10] and above the transverse processes of the vertebrae, where substantial epaxial muscles lie underneath the subdermal fascial plane [11]

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Results

Conclusion