Credit: Marine Futures Lab
Our publication in Marine Biodiversity, “Interannual changes in the benthic and pelagic communities of the Shark Bay World Heritage Area”, focuses on the marine communities of Shark Bay, Western Australia. We used a multi-year dataset of both seabed and midwater baited remote underwater video systems (BRUVS) to investigate benthic and pelagic marine communities alongside each other and determine whether interannual trends were similar between these two habitats.
The overall trends in benthic and pelagic communities differed across a five-year period, with both showing significant changes to community composition between years. However, benthic communities were broadly stable in key metrics such as abundance and biomass, while pelagic communities increasingly favoured larger abundances of smaller fishes through our study period, which may indicate excessive fishing pressure in the Shark Bay World Heritage Area.
We recorded multiple species listed as Threatened on the IUCN Red List. The increasingly imperilled wedgefishes were a regular feature of Shark Bay’s benthic habitat. Multiple juvenile shortfin mako sharks were recorded in pelagic surveys, two of which were under 60cm in fork length and likely to be no more than a month old, implying the existence of a nearby pupping site for the species. The presence of Threatened species in communities that exhibit significant interannual change emphasises both the great potential of Shark Bay as a refuge for marine biodiversity in Western Australia, and the need for responsible management.