Project number:
2017-027
Project Status:
Completed
Budget expenditure:
$140,000.00
Principal Investigator:
Timothy M. Ward
Organisation:
SARDI Food Safety and Innovation
Project start/end date:
30 Sep 2017
-
27 Feb 2019
Contact:
FRDC
SPECIES
Accurate and precise estimates of spawning biomass are needed to underpin sustainable management of Australia's largest fishery, the SASF.
Estimates of mean daily egg production that underpin application of the DEPM need to be as accurate and precise as possible.
A new sampling technique that provides more precise estimates of mean egg density is needed to refine estimates of mean daily egg production.
The benefits/costs of using the new sampler need to be validated before it can be used to underpin future management of the SA Sardine Fishery.
1. To improve the accuracy and precision of estimates of spawning biomass obtained using the Daily Egg Production Method.
Final report
ISBN:
Validating a new sampling technique for estimating egg production
Authors:
Ward
T.M.
McGarvey
R.
Ivey
A. and Grammer
G.L.
Final Report
•
2020-03-01
•
1.73 MB
2017-027-DLD.pdf
Estimates of spawning biomass obtained using the Daily Egg Production Method (DEPM) are the primary biological performance indicator in the South Australian Sardine Fishery (SASF) and Commonwealth Small Pelagic Fishery (SPF). The DEPM is also being used to assess the status of other commercially-important species, e.g. Snapper in South Australia.
The objective of this study was to improve the accuracy and precision of estimates of spawning biomass obtained using the DEPM. To address this objective, we evaluated the potential benefits of using a high speed oblique sampler (Nackthai net) instead of the traditional vertically-towed CalVET and Bongo nets to measure egg density.
Estimates of egg density and P0 Derived from the Nackthai were lower and less precise than those obtained from the Calvet or Bongo. Due to its large size and cumbersome design (e.g. 22 kg depressor), the Nackthai was more difficult to deploy in rough weather and required more staff than the other samplers. Samples obtained from the Nackthai also contained more eggs and took longer to process in the laboratory than those from the other nets. There was no evidence to suggest that replacing traditional samplers with the Nackthai would enhance application of the DEPM to Australian Sardine or other small pelagic fish.
