Project number: 2023-068
Project Status:
Current
Budget expenditure: $144,462.00
Principal Investigator: Toby Patterson
Organisation: CSIRO Environment
Project start/end date: 2 Oct 2023 - 27 Feb 2025
Contact:
FRDC

Need

As a species listed under CITES Appendix II, SHH are harvested under a total allowable catch of 200t, which was implemented for Australia to meet its obligations under non-detriment findings. Further, the conservation status of SHH is currently being reassessed under the EPBC Act. A recent SHH stock assessment undertaken using data poor methods highlighted the paucity of data available for the species and, importantly, that informative data will almost certainly not be available in the foreseeable future. Therefore there is no expecation that current uncertainty will resolve with status-quo data collection strategies.

New approaches, such as CKMR, are required to gather informative data to better understand stock status and verify that the 200t catch limit is appropriate. The project proposed here aims to explore likely scenarios to determine the sample size, budget, and required sampling logistics in order to obtain either an estimate of spawning abundance of SHH stocks found in northern Australia, or to determine that the current catch limits will not be detrimental to the sustainability of the species. This project intends to utilise available fisheries observer data and the current understanding of population trends and demographic information to evaluate

(1) whether the species is a viable candidate for close-kin mark-recapture assessments, and

(2) the extent of sampling required to produce a precise estimate of population abundance and/or other population metrics useful for management.

Objectives

1. Expand recent stock assessment work to parameterise plausible alternative population models for the Australian/SE Asian region, accounting for uncertainty in catch history and stock structure
2. Explore sampling avenues for Australian as well as international jurisdictions, including stakeholder consultation on the feasibility of potential sampling scenarios
3. Estimate sampling / logistical costs of various sampling schemes. This would include information on achievable rates of sample accumulation and sequencing costs to deliver estimates of abundance with acceptable uncertainty (e.g. a coefficient of variation &lt
20%).
4. Determine the feasibility of CKMR for Scalloped Hammerhead in Northern Australia and the Indo-Pacific.

Related research

Industry
Industry
Industry
PROJECT NUMBER • 2023-012
PROJECT STATUS:
CURRENT

Reviewing solutions to reduce unwanted fisher interactions with elasmobranchs

1. Review the existing peer-reviewed and grey literature to collate information on the range of methods trialled to date for reducing shark interactions with fishing and assess their relative effectiveness
ORGANISATION:
Department of Agriculture and Fisheries EcoScience Precinct