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Title:

PIRSA: Surveying, searching and promoting cuttlefish spawning activity in northern Spencer Gulf

Project Number:

2013-032

Organisation:

South Australian Research and Development Institute

Principal Investigator:

Mike A. Steer

Project Status:

Completed

FRDC Expenditure:

$200,000.00

Program(s):

Environment

Final Report - 2013-032-DLD - Surveying, Searching and Promoting Giant Australian Cuttefish Spawning Activity in Northern Spencer Gulf

Final Report
ISBN:978-1-921563-74-4
ISSN:
Author(s):Michael Steer
Date Published:March 2015
The size of the Giant Australian Cuttlefish (Sepia apama) population on the Point Lowly spawning grounds in 2014 increased for the first time since 2009, yet management is remaining cautiously optimistic as the reason for this increase is currently unknown.  In addition to the annual assessment of the spawning aggregation this project, coordinated by SARDI (Aquatic Sciences), addressed a number of other key knowledge gaps as indentified by the Giant Cuttlefish Working Group (GCWG) and forms part of a larger collaborative research initiative undertaken by PIRSA, SARDI (Aquatic Sciences), The University of Adelaide, South Australian Museum and the Environmental

Protection Authority through combined State and Federal funding.  There is a commitment by all levels of government to understand more about the biology and ecology of this species to assist in determining the future management actions required to ensure its sustainability.  The specific focus of this study’s research related to determining the relative significance of the Point Lowly aggregation within Northern Spencer Gulf; the impact of commercial fishing and industrial pollution (heavy metals) within the area on the population; and if spawning activity could be promoted in other areas away from historic breeding grounds through the use of artificial spawning habitat.  The scope of research was diverse, involving extensive diver-based and video-based surveys; design, construction and deployment of artificial habitat; broad-scale collection of biological samples; and close collaboration with the commercial fishing industry within northern Spencer Gulf throughout 2013 and 2014. 

Key Words:  Giant Australian Cuttlefish, spawning, aggregation, population dynamics, by-catch, heavy metals, Spencer Gulf.

Objectives

1. To use the standard survey methodology described in Steer et al. (2013) to estimate cuttlefish abundance and biomass of the Point Lowly spawning aggregation, characterise the spawning habitat and analyse the ambient water quality.

2. To explore and assess the potential of alternate cuttlefish spawning areas in northern Spencer Gulf.

3. Characterise the natural spawning substrate during the 2013 spawning season.

4. Use the ‘natural spawning preference’ information to design and develop artificial habitat with the intention of strategically deploying it in northern Spencer Gulf prior to the 2014 spawning season.

5. Determine the potential impact of fishing on giant cuttlefish in northern Spencer Gulf.

6. To assess whether there are abnormally high levels of metals accumulating in giant cuttlefish in northern Spencer Gulf.