Latitude, depth and environmental variables influence deepwater fish assemblages off Western Australia

Authors

Claire M. Wellington, Department of Primary Industries and Regional DevelopmentFollow
Euan S. Harvey, Curtin University
Corey B. Wakefield, Department of Primary Industries and Regional DevelopmentFollow
Dave Abdo, Department of Primary Industries and Regional Development
Stephen J. Newman, Department of Primary Industries and Regional DevelopmentFollow

Document Type

Article

Publication Date

2-25-2021

Journal Title

Journal of Experimental Marine Biology and Ecology

ISSN

Print: 0022-0981 Electronic: 1879-1697

Keywords

Stereo-BRUVs, Abundance, Biomass, Continental shelf, Continental slope, Demersal

Disciplines

Aquaculture and Fisheries | Marine Biology

Abstract

Continental shelf and upper slope fishes are important global resources which have significant economic and biodiversity values. Understanding the drivers of their abundance and distribution are fundamental to guide sustainable fisheries management arrangements. Deepwater demersal fish assemblages were sampled between depths of 91–570 m at six locations along the Western Australian coastline spanning 17° of latitude (i.e. 17–34°S at the Rowley Shoals, Montebello Islands, Ningaloo Reef, Abrolhos Islands, Perth Canyon and South West Capes) using Baited Remote Underwater Stereo-Video systems (stereo-BRUVs, n = 417 deployments). A total of 5965 individual fishes were identified belonging to 252 species and 92 families. Assemblage composition data were modelled against in-situ habitat data, temperature, salinity, current speed, and current direction. Multivariate statistical analyses revealed that fish assemblage composition was predominantly influenced by latitude (9.5% of variation), depth (7.3%) and salinity (7.2%). Three distinct assemblages were defined in response to latitude; a tropical, a sub-tropical and a southern temperate bioregion. Species richness declined with increasing latitude, and average biomass was highest in the southern bioregion. A mid-depth peak in biomass and lengths indicated the dominance of meso-predator species in the 300–399 m depth range. The information provided by this study on the factors influencing the abundance and distribution of fish assemblages over an exceptionally broad depth and latitudinal range along a continuous coastline will be useful for predicting the effects of future climate shifts on this and similar teleost species occupying tropical and temperate oceans elsewhere.

Recommended Citation

Wellington, C M, Harvey, E S, Wakefield, C B, Abdo, D, and Newman, S J. (2021), Latitude, depth and environmental variables influence deepwater fish assemblages off Western Australia. Journal of Experimental Marine Biology and Ecology, 539 (151539).
https://library.dpird.wa.gov.au/fr_fja/104