Ecological features and swimming capabilities of deep-sea sharks from New Zealand. (February 2020)

• Record Type: Journal Article
• Authors: Pinte, Nicolas; Parisot, Pascaline; Martin, Ulrich; Zintzen, Vincent; De Vleeschouwer, Christophe; Roberts, Clive D.; Mallefet, Jérôme
• Is Part Of: Deep sea research. Volume 156(2020)
• Publication Date: 2020-02
• Subjects: Deep-sea sharks -- Swimming speed -- Stereo-BRUVs -- Squaliformes -- Bioluminescent -- Isolume-followers; Oceanography -- Periodicals; Océanographie -- Périodiques; 551.4605
• DOI: 10.1016/j.dsr.2019.103187
• Languages: English
• ISSNs: 0967-0637

Abstract

Abstract: Currently the ecology of deep-water sharks is poorly documented, especially in situ information for these elusive species are lacking. In this study, stereo-Baited Remote Underwater Videos (stereo-BRUVs) were deployed to collect ecological data from New Zealand deep-sea sharks. The results showed differences in abundance between species, with Etmopterus granulosus (Etmopteridae) found in greatest numbers. Moreover, the known depth range increased for Scymnodon macracanthus (Centrophiridae). Deep-sea shark species were generally found to swim at slower cruise speeds (0.36 ± 0.04 m s −1 ) than their shallow-water counterparts (0.63 ± 0.05 m s −1 ). However, the swimming speed of deep-sea sharks was clearly not uniform, with some species displaying higher cruise swimming speeds than others. The fastest sharks ( Centrophorus harrissoni, Etmopterus granulosus and Etmopterus molleri ) had swimming abilities comparable to benthic shallow water sharks (0.48 ± 0.02 m s −1 ). The higher cruise swimming speed in the family Etmopteridae could be an advantage for these luminous sharks if they follow isolumes to match their ventral light intensity with the down-welling light of their environment. This study revealed that alternative non-destructive methods can be effective for ecological studies of deep-sea marine fauna. Highlights: Deep-sea sharks display a lower cruise swimming speed than shallow-water ones. Luminous Etmopteridae swim faster than others deep-sea species. Different swimming speeds and tail beat frequencies in different deep-sea species. The occurrence and relative abundance of sharks at different depths. Slight or no size change with depth.