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Title:

SRL IPA: Developing cost-effective industry based techniques for monitoring puerulus settlement in all conditions: trials in southern and western Tasmania

Project Number:

2011-020

Organisation:

University of Tasmania (UTAS)

Principal Investigator:

Stewart Frusher

Project Status:

Completed

FRDC Expenditure:

$119,711.00

Program(s):

Environment, Industry

Need

Rock lobster fisheries throughout southern Australia are in decline with resultant direct and indirect losses of hundreds of millions of dollars annually. While the cause for the decline is uncertain, observed declines in the recruitment of larvae is of concern in western and eastern Australia. In Australia, larval (puerulus) collectors have been established in shallow water regions where they are serviced by divers (SA, Tas & Vic) and from dinghies (WA). By requiring servicing by department staff, and particularly by dive teams, collectors are expensive to service and thus limited in their regional distribution to a few sites. For southern rock lobster there has been concern over how well the observed larval settlement represents the entire fishery as sampling sites are few and the majority of catch is from deeper reefs. To improve our understanding of the relationship between recruitment, future catches and short and long term recruitment trends, there is a need to improve spatial (region and depth) coverage. Previous attempts to deploy puerulus collectors in shallow regions in southern and western Tasmania, where over 60% of the catch is obtained, have failed due to weather conditions. To-date there has been no attempt to trial deeper water collectors. This proposal requests funding for phase 1, the development and trial of deepwater collectors, of a 3 phase project with the ultimate aim to develop cost-effective collectors that can withstand all weather conditions, can be serviced in deeper water and can be serviced by the fishing industry throughout southern Australia.

Objectives

1. To develop a puerulus collector that can be (a) used in deep water (b) can withstand adverse weather conditions as experience in SW Tasmania and (c) be serviced by the fishing Industry ($113,195)

2. To evaluate the potential and cost-effectiveness of remote sampling (camera and satellite transmission) ($5,000).

Final report - 2011-020-DLD - Developing cost-effective industry based techniques for monitoring puerulus settlement in all conditions: trials in southern and western Tasmania- proof of concept

Final Report
ISBN:978-1-86295-927-9
ISSN:
Author(s):Stewart Frusher
Date Published:January 2013

​Principal Investigator: Stewart Frusher

Key Words: Puerulus, larval settlement, deep water, lobster fisheries, industry monitoring, remote camera

Summary:  This proposal requested funding for phase 1, the development and trial of deepwater collectors, of a 3 phase project with the ultimate aim to develop cost-effective collectors that can withstand all weather conditions, can be serviced in deeper water and can be serviced by the fishing industry throughout southern Australia.

 
Through consultation with industry a design for a deep water collector was developed. Prototypes of this design were constructed and tested in aquaria with captured pueruli, on the seafloor adjacent to an existing inshore shallow collector site on the east coast of Tasmania, and in deep water on the south and southwest coasts of Tasmania. The prototype collectors were successfully deployed, retrieved and serviced by vessels in the commercial lobster fleet and vessel masters reported that the design facilitated safe and efficient handling on deck. The prototypes collected significantly more puerulus than adjacent routine collectors in deployments at the shallow site and collected puerulus for the first time on the deeper and more exposed southwest coast of Tasmania.

Final report - 2011-020-DLD - Developing cost-effective industry based techniques for monitoring puerulus settlement in all conditions: trials in southern and western Tasmania- proof of concept

Final Report
ISBN:978-1-86295-927-9
ISSN:
Author(s):
Date Published:January 2013

​Principal Investigator: Stewart Frusher

Key Words: Puerulus, larval settlement, deep water, lobster fisheries, industry monitoring, remote camera

Summary:  This proposal requested funding for phase 1, the development and trial of deepwater collectors, of a 3 phase project with the ultimate aim to develop cost-effective collectors that can withstand all weather conditions, can be serviced in deeper water and can be serviced by the fishing industry throughout southern Australia.

 
Through consultation with industry a design for a deep water collector was developed. Prototypes of this design were constructed and tested in aquaria with captured pueruli, on the seafloor adjacent to an existing inshore shallow collector site on the east coast of Tasmania, and in deep water on the south and southwest coasts of Tasmania. The prototype collectors were successfully deployed, retrieved and serviced by vessels in the commercial lobster fleet and vessel masters reported that the design facilitated safe and efficient handling on deck. The prototypes collected significantly more puerulus than adjacent routine collectors in deployments at the shallow site and collected puerulus for the first time on the deeper and more exposed southwest coast of Tasmania.