Spatio-temporal variability in the demersal fish assemblage on the outer continental shelf of the Great Australian Bight

Nitschke, Joshua; Knuckey, Ian; Koopman, Matt; Hudson, Russell; Huveneers, Charlie; Grammer, Gretchen L.; Ward, Tim M.

doi:10.1016/j.ecss.2022.107852

Cited by 2 publications

(1 citation statement)

References 84 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Reduction in the prey resources AUFS depend upon are likely due to ecosystem changes. Indeed, there has been sustained low biomass levels of several commercial fish species which have not recovered despite reduced fishing pressure (Edgar et al, 2018;Nitschke et al, 2022), suggesting wider ecosystem changes have occurred. While the exact linkages between environmental variables and prey diversity, abundance and distribution for the species are not known (Kirkwood et al, 2008;Kliska, 2016;Kliska et al, 2022), the results of the present study demonstrate local-and broad-scale influences on AUFS body condition over the last two decades.…”

Section: Body Condition Decrease: Potential Causes and Implicationsmentioning

confidence: 99%

Long-term decline in body condition of female Australian fur seals: potential causes and implications

Geeson,

Hindell,

Hobday

et al. 2023

Front. Mar. Sci.

View full text Add to dashboard Cite

The Australian fur seal (Arctocephalus pusillus doriferus, AUFS) population is still recovering from the over-exploitation of the commercial-sealing era (18th and 19th centuries). While the population is considered to be only < 47% of its pre-harvest size, it now represents the greatest resident marine predator biomass in the south-eastern Australian marine ecosystem. The region is experiencing rapid environmental change and, as a keystone predator species, the AUFS is an indicator of ecosystem health. In the present study, the body mass, standard length and body condition index (BCI) were analysed between 1997-2021 in adult female AUFS provisioning pups on Kanowna Island (northern Bass Strait), the third largest colony for the species. While substantial inter-annual fluctuations were observed, there was no temporal trend in standard length during the 23-year study period. In contrast, body mass and, consequently, BCI decreased significantly, suggesting the population is experiencing changing nutritional conditions. While these changes do not appear to be due to competition with commercial fisheries or population expansion, weak but significant negative relationships were observed between BCI and 1-year lagged sea surface temperature and summer zonal winds in the Bonney Upwelling region, and both current- and 2-year lagged Indian Ocean Dipole (IOD). These findings suggest the BCI of AUFS may continue to decline under predicted climate change conditions. While a lack of a concurrent decline in pup production could indicate a degree of nutritional tolerance or flexibility in energy allocation, further monitoring is required to assess decreases in reproductive parameters (e.g., birth mass, pre-weaning growth rates) or vital rates, which would be expected with continued nutritional stress.

show abstract

Section: Body Condition Decrease: Potential Causes and Implicationsmentioning

confidence: 99%

Long-term decline in body condition of female Australian fur seals: potential causes and implications

Geeson,

Hindell,

Hobday

et al. 2023

Front. Mar. Sci.

View full text Add to dashboard Cite

show abstract

Difference in seasonal shift of spatial homogenization between taxonomic and functional structure in demersal fish communities

Li,

Ma,

et al. 2023

Estuarine, Coastal and Shelf Science

View full text Add to dashboard Cite

Spatio-temporal variability in the demersal fish assemblage on the outer continental shelf of the Great Australian Bight

Cited by 2 publications

References 84 publications

Long-term decline in body condition of female Australian fur seals: potential causes and implications

Long-term decline in body condition of female Australian fur seals: potential causes and implications

Difference in seasonal shift of spatial homogenization between taxonomic and functional structure in demersal fish communities

Contact Info

Product

Resources

About