Fisheries biology of the cuttlefish (Sepia apama Gray) in South Australian waters

Project number: 1998-151

Project Status:

Completed

Budget expenditure: $131,648.60

Principal Investigator: Anthony J. Fowler

Organisation: SARDI Food Safety and Innovation

Project start/end date: 28 Jun 1998 - 30 Dec 2003

Contact:

FRDC

Need

This project aims to provide the biological knowledge to sustainably manage a new species in South Australian fisheries production. It also aims to maximise returns for a species which, until recently, yielded low returns to fishers but has significant potential in export markets.

Targeted fishing effort on the cuttlefish Sepia apama has rapidly increased in northern Spencer Gulf during recent years. Annual reported catches have increased from less than 4 tonnes to more than 250 tonnes within 5 years. Licence holders in the fishery have expressed strong concerns over the sustainability of the fishery which is restricted to a spatially small area near Pt Lowly. The fishery is currently managed within the broad management framework of the commercial marine scalefish fishery, which provides for no specific restrictions on either effort or catch for cuttlefish. More stringent management controls, specific to this species, need to be introduced before the commencement of the 1998 fishing season.

There is a complete lack of scientific information regarding the general biology and life history characteristics of S. apama, despite its large size and common occurrence in southern Australian waters. Other commercial cuttlefish species are known to be short-lived and semelparous (spawns once and dies), a lifecycle common to many cephalopods. With this type of lifecycle, overfishing in a single year can cause a stock to collapse (Rodhouse and White, 1995). In addition, the exploited population is understood to be a spawning aggregation, which would further increase the potential to deplete the stock.

An improving market for this species, including the potential for an export market, suggests that exploitation levels will continue to increase. Additionally, other known populations within South Australia and other southern States (currently unfished) may attract fishing effort. There is therefore an urgent need to establish the general life history characteristics of S. apama in South Australian waters, and gather baseline biological data upon which the impacts of fishing on this species may be assessed and any necessary management controls may be based.

Currently South Australian cuttlefish are attracting a much lower market price than other cuttlefish species of a similar size being sold in Japanese and European markets (AUS$1-2 as compared with US$5-7). Therefore, there is a definite need to investigate possible marketing strategies which would increase the price of the current product and/or identify alternative value-added products (especially if they utilise other parts of the cuttlefish currently being discarded). An even more exciting opportunity may exist with the live fish trade.

Rodhouse PG and White MG (1995). Cephalopods occupy the ecological niche of epipelagic fish in the Antarctic polar frontal zone. Biol. Bull. 189: 77-80.

Objectives

1. To establish the general life history characteristics of S. apama in South Australian waters, including growth, age and reproductive biology.

2. To estimate the abundance of cuttlefish in the Pt Lowly fishing grounds and its relationship to the commercial and recreational catch.

3. To investigate egg densities, recruitment and the relationship with adult abundance, timing of spawning and its interaction with the fishery.

4. To investigate the structure and seasonal movement patterns of the exploited population and its relationship with other known populations in South Australian waters.

5. To investigate marketing strategies aimed at increasing the value of the current cuttlefish product and/or identifying alternative value-added products.