Population dynamics and spatial structure of the grey rockcod (Lepidonotothen squamifrons) in the vicinity of Heard Island and the McDonald Islands

• Published in: PLOS ONE
• Main Authors: Maschette, Dale, Burch, Paul, Farmer, Bryn, Woodcock, Emma, Péron, Clara, Cramer, Breanna, Gardner, Caleb, Welsford, Dirk, C
• Other Authors: Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), University of Tasmania Hobart, Australia (UTAS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2024
• Subjects: [SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Southern Ocean; Kerguelen; Heard Island; Heard; McDonald Islands; Patagonian Toothfish
• Online Access: https://hal.science/hal-04575590; https://hal.science/hal-04575590/document; https://hal.science/hal-04575590/file/Maschette%20Plos%20One%20-%20rockcod%20biology%202024.pdf; https://doi.org/10.1371/journal.pone.0298754

International audience The grey rockcod, Lepidonotothen squamifrons is an important prey species for seals, penguins and Patagonian toothfish ( Dissostichus eleginoides ) in the Southern Ocean. Across the Kerguelen Plateau, the species was fished to commercial extinction ( ca . 152 000 tonnes between 1971 and 1978) prior to the declaration of the French Exclusive Economic Zone in 1979 and the Australian Fishing Zone in 1981. In this study we estimate; age, growth, maturity, sex ratio, body condition (weight-at-length), and population density of grey rockcod using data from 19 trawl surveys from 1990 to 2014. There appeared to be three distinct geographical populations, with differences in biological parameters within each population. This study has identified separate metapopulations within the southern region of the Kerguelen Plateau and we recommend that management should take into account the different characteristics of these populations, and that this meta-population structure may be a factor in why this species required several decades to show signs of recovery.