The Challenge to Observe Antarctic Toothfish (Dissostichus mawsoni) under Fast Ice

Abstract

In situ observation of Antarctic toothfish (Dissostichus mawsoni) is challenging as they typically live at depths greater than 500 m, in dark and ice-covered Antarctic waters. Searching for adequate methodologies to survey Antarctic toothfish in their habitat, we tested a miniaturized Baited Remote Underwater Video camera (BRUV), deployed through holes drilled in the sea ice in the Ross Sea region, over three field seasons. In 2015 three BRUVs were deployed at McMurdo Sound, and paired with a vertical longline sampling. In 2017, three opportunistic deployments were performed at Terra Nova Bay. In 2018 seven deployments at Terra Nova Bay provided preliminary data on the habitat preferences of the species. The design and configuration of the mini-BRUV allowed to collect high-quality video imagery of 60 Antarctic toothfish in 13 deployments from the fast sea ice. The behaviour of fish at the bait, intra-species interactions, and potential biases in individual counting were investigated, setting baselines for future studies on the abundance and distribution of Antarctic toothfish in sea-ice covered areas. This work represents the first step towards the development of protocols for non-extractive monitoring of the Antarctic toothfish in the high-Antarctica coastal shelf areas, of great value in the Ross Sea region where the largest MPA of the world has recently been established.

Ecomorphological Differentiation of Feeding Structures within the Antarctic Fish Species Flock Trematominae (Notothenioidei) from Terra Nova Bay (Ross Sea)

“…It feeds mainly on fish and secondarily on polychaetes and hard prey such as decapod crustaceans [11], combining manipulation and suction feeding based on the prey availability. It has been also recorded by means of baited cameras to employ scavenging activity on organisms larger than its own size, from which it powerfully bites and detaches pieces using rotational feeding [53], a common method used by nototheniids to handle large food pieces [54]. Furthermore, T. hansoni and T. bernacchii are benthic species that share the ability to be planktivorous if necessary [5].…”

First records of Chionodraco hamatus nests in coastal areas of Terra Nova Bay (Ross Sea): a potential nesting area for the species?

“…The Drygalski Ice Tongue, the Nansen Ice Sheet and the Campbell Glacier Tongue descend from the continent toward the bay. The coastline is indented with embayments, including Gerlache Inlet and Silver sh Bay in the northern part, with an average depth of about 500 metres and irregular bottom topography, characterized by steep bottoms consisting of granitic rock ridges and gullies lled with gravel, clay, and silt (Vacchi et al 2012;Di Blasi et al 2021). The study area, in the ASPA No.…”

Coastal Fish Research

“…This special edition is intended to be a contribution to the knowledge of several aspects of fish biology and ecology: coastal fish diversity, coastal fisheries and commercial species, biological invasions process and non-indigenous species, interactions between fish and their environment, ethology, bioaccumulation and reproduction [1][2][3][4][5][6][7][8][9][10][11][12]. I hope this special issue will be helpful for all marine biologists involved in studies on fish biology and ecology.…”