Fishing for science around Heard Island – Australian Antarctic Program (News 2023)

Consulting the bones

To assist perceive the inhabitants construction of Patagonian toothfish populations, researchers just like the AAD’s Mr Andy Nicholls, conduct ageing research on the fish caught, utilizing their ear bones or ‘otoliths’.

“Like tree rings, otoliths include annual progress rings manufactured from calcium carbonate, which we use to age particular person fish,” Mr Nicholls defined.

The AAD has a group of otoliths from 163,000 fish, and a database of data regarding the intercourse, weight and size of every fish, in addition to the place, when and the way every fish was caught. The oldest toothfish within the assortment is estimated to be 67 years previous.

Throughout the voyage, Dr Cleeland, Dr Appert, and scientific observers, collected otoliths and related knowledge so as to add to the gathering.

Utilizing this info, scientists can higher outline the age construction of the toothfish inhabitants, the popular habitats of juveniles and adults, and which age teams are notably prone to fishing gear.

Fashions developed utilizing this info permit the Australian Fisheries Administration Authority and the Fee for the Conservation of Antarctic Marine Dwelling Assets to set precautionary catch quotas for the toothfish fishery at HIMI.

“This voyage was an excellent instance of collaborative science and the way business and scientists can work collectively to conduct analysis that advantages each pursuits and helps minimise or keep away from impacts on the broader ecosystem,” Dr Cleeland mentioned.

2022-012 Quantifying post-release survival of skate bycatch within the Heard Island and McDonald Islands (HIMI) Patagonian Toothfish longline fishery is supported by funding from the FRDC on behalf of the Australian Authorities