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Lethal sampling of stingrays (Dasyatidae) for research

Posted on 13 March 2013

TitleLethal sampling of stingrays (Dasyatidae) for research
Publication TypeConference Proceedings
Year of Conference2012
AuthorsO'Shea, OR, Meekan MG, van Keulen M
Conference Name2012 ANZCCART Conference
PublisherAustralian and New Zealand Council for the Care of Animals in Research and Teaching Ltd.
Conference LocationPerth
ISBN Number978 - 0 - 9874657 - 0 -
KeywordsAnimal ethics, coral reefs, destructive techniques, rays, scientific sampling
AbstractFor some species certain biological and ecological data, such as diet, age and growth estimates can only be obtained through lethal sampling of study animals. Traditionally, commercial fishermen have provided samples of rays caught in nets for use by biologists; however, by-catch exclusion devices now prevent medium and larger-bodied rays (>100 cm disc width) from being collected in trawl nets. This means that other methods must be used for lethal sampling. We obtained a large suiteof biological and ecological data from 170 wild-caught stingrays collected from Ningaloo Reef, Western Australia over two years. Our sampling program was designed to minimize or eradicate any pain and suffering to the animals, while ensuring the safety of researchers undertaking the sampling process. Small rays (<100 cm disc width; WD) were caught in beach seines and euthanized immediately by destruction of the brain and severance of the spinal cord with a reinforced, serrated steel knife. Larger rays were euthanized by firing high-powered spears directly into their brains from close range while free diving. Of the 170 rays sampled in this manner, 94 % (159) were killed instantly or within an estimated 10-30 seconds of capture. The design and application of this lethal sampling program was deemed successful in terms of ensuring the safety of researchers as well as minimising suffering to rays. Pain perception in elasmobranchs has been quantified by few studies; however, research suggests that certain neural apparatus associated with pain sensation is lacking in rays. Our study has provided critical data on the biology and life history of stingrays that could not be obtained by any other means.