Title:

Development and assessment of methods to reduce the predation of pot-caught southern rock lobster (Jasus edwardsii) by maori octopus (Octopus maorum)

Project Number:

1998-150

Organisation:

University of Adelaide North Terrace Campus

Principal Investigator:

Tim Ward

Project Status:

Completed

FRDC Expenditure:

$205,592.00

Program(s):

Environment

Development and assessment of methods to reduce the predation of pot-caught southern rock lobster (Jasus edwardsii) by maori octopus (Octopus maorum)

Final Report
ISBN:0-7308-5297-0
ISSN:
Author(s):Tim Ward
Date Published:July 2010

The SARLF is the State’s most valuable wild fishery with estimated export earnings of >$100 million in 2002.  The fishery is a closed entry fishery with 250 licence-holders and is divided into the Northern and Southern Zones. Lobsters are caught in baited pots that are generally set for 24 hours prior to hauling.

Mortality of lobsters due to predation in pots, especially by maori octopus is a significant problem in the SARLF, but has generally been considered to be unavoidable, and minimal effort has been expended determining the scale of the problem or investigating a solution. This project was initiated in 1998 to develop methods for reducing rates of octopus predation on lobsters in pots.

Objectives

1. Describe the spatial and temporal changes that have occurred in octopus predation level over the last 15 years.

2. Determine how environmental factors influence octopus predation levels over a fishing season.

3. Identify pot modifications that have the potential to prevent/reduce octopus predation of pot caught Southern Rock Lobster.

4. Trial pot designs to prevent/reduce octopus predation under laboratory conditions.

5. Develop a pot that under commercial fishing conditions, prevents/reduces octopus predation, maintains lobster catch rates and is cost effective to implement.

6. Ensure industry participation and consultation at all stages of the project.

7. Ensure adoption of the modified pot(s) by industry where appropriate.