Project number: 2018-159
Project Status:
Completed
Budget expenditure: $300,000.00
Principal Investigator: Timothy M. Ward
Organisation: SARDI Food Safety and Innovation
Project start/end date: 19 Dec 2018 - 27 Feb 2019
Contact:
FRDC
SPECIES

Need

This project is needed to ensure that the TAC for Jack Mackerel in the East sub-area of the SPF does not fall from 18,890 t to 9,469 t in 2020/21.

A survey to estimate the spawning biomass of Jack Mackerel in the East sub-area needs to be conducted in January 2019 to maintain the stock at Tier 1.

Jack Mackerel East needs to stay at Tier 1 to ensure that sufficient catch is available to support the new mid-water trawl operation that has recently been established off Ulladulla.

Fish taken by this operation are needed to sustain the new fish processing factory recently established in the region by Ridleys.

Objectives

1. To conduct ichthyoplankton and trawl surveys in the East sub-area of the SPF during January 2019. (Note: amended to January-February 2019)

Final report

ISBN: 978-1-876007-15-7
Author: Tim Ward and Alex Ivey
Final Report • 2019-05-01 • 665.28 KB
2018-159-DLD.pdf

Summary

Estimates of spawning biomass obtained using the Daily Egg Production Method (DEPM) are the primary biological performance indicator for quota species in the Small Pelagic Fishery (SPF).

The objective of this study was to conduct ichthyoplankton and adult trawl surveys that underpin the DEPM in the East sub-area of the SPF during January-February 2019.

Eggs and larvae of Jack Mackerel and other species were collected from FV Santo Rocco during 15 January to 7 February 2019.  Samples were collected in vertical tows made using a bongo net. The locations of the plankton sampling sites are shown in the figure below (yellow circles). Plankton samples for morphological identification of eggs and larvae were fixed in a formalin solution. Samples to be used in a genetic validation study were fixed in an ethanol solution. An ethanol sample was taken on every second station. The total survey comprised of 205 formalin and 102 ethanol preserved samples.

Adult Jack Mackerel were sampled using a modified demersal trawl net deployed from the FV Santo Rocco during 15 January to 7 February 2019, in shelf and slope waters within the survey area. The locations and dates where trawls were undertaken are shown in the figure below (red circles). In trawls where Jack Mackerel were present, fish were dissected and sexed. Gonads of mature female Jack Mackerel were removed, labelled and fixed in a formalin solution. Females with ovaries removed, and mature males were labelled and frozen. Jack Mackerel were present in 13 of the 19 trawls and seven trawls had suitable numbers of adult fish.

The results of this project and the laboratory and statistical analyses that will be conducted in a related project funded by the Australian Fisheries Management Authority (AFMA) will be presented to the Resource Assessment Group for the SPF in late 20019.

The estimates of spawning biomass obtained in the AFMA study will be used to the RBC and TAC for Jack Mackerel in the East sub-area of the SPF in 2020/21. 

Related research

Environment
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PROJECT NUMBER • 2017-098
PROJECT STATUS:
COMPLETED

Southern Bluefin Tuna: Changing The Trajectory

1. To inform the recreational fishing sector and general public of the history and current status of SBT, including the role of science
ORGANISATION:
Australian Fisheries Management Authority (AFMA)
Environment