101 results
Environment
PROJECT NUMBER • 2017-149
PROJECT STATUS:
COMPLETED

Planning for a Blue Future Salmon - informing R&D, regulation and industry development

The Tasmanian salmon industry is seeking to grow production safely and sustainably in the next two decades, further increasing the tangible benefits to the Tasmanian community. Our aim, through the Tasmanian Global Salmon Symposium partnership, is to deliver this by being the most environmentally...
ORGANISATION:
University of Tasmania (UTAS)

Live transport of crustaceans in air - prolonging the survival of crabs

Project number: 1992-071
Project Status:
Completed
Budget expenditure: $100,832.33
Principal Investigator: Brian Paterson
Organisation: Department of Primary Industries (QLD)
Project start/end date: 11 Oct 1992 - 25 Jan 1996
Contact:
FRDC

Objectives

1. To increase knowledge of the techniques required for successful live transport of crabs destined for live export or domestic markets
2. To put this knowledge to commercial practice in developing guidelines and protocols

Final report

Author: Brian Paterson
Final Report • 1995-01-09 • 4.60 MB
1992-071-DLD.pdf

Summary

We studied the live transport of crustaceans in air, using the spanner crab Ranina ranina as an example, and developed guidelines for handling live spanner crabs which we presented to an industry workshop. Our findings were also of general relevance to the live shipment of other oceanic crab species.

The spanner crab fishery has burgeoned over the last couple of years through interest in the live market. The choice of spanner crabs as a topic of study was therefore timely. The handling practices used on boats in this fishery, (storing crabs out of water) , were appropriate for handling "live" crabs destined for cooking but we found that more careful handling was required for the live export market.

While spanner crabs appeared to tolerate being stored in air, our studies showed that this tolerance was misleading. The crabs stressed quickly when they arrived on deck and became quiescent. Their blood pH fell rapidly, a symptom called acidosis. Quiescence was their only means of dealing with acidosis.

In practical terms, any time that a spanner crab was out of water was too long. Spanner crabs are stored in air twice after harvest, first while on the boat and again when actually exported. The conditions experienced by the crabs stored in air at ambient temperature on boats were much worse than those of crabs cooled for export. At the very least, the crabs should be cooled down or sprayed with cold seawater when stored in air on boats. The best way to store crabs on boats would be submerged in live wells- but there are problems with this because the unrestrained crabs can injure each other.

We also tested other methods of alleviating stress. Spanner crabs cannot buffer low pH in the blood, unlike many other commercially harvested crustaceans. We sought to correct this using a dip treatment. However, this did not improve their survival . For an animal that cannot correct acidosis, spanner crabs survive for an extraordinary period in air. The stressed crabs may linger on because they "shut down" and keep the acidosis from reaching fatal levels.

Using the results of our research, we presented guidelines for handling spanner crabs at an industry workshop on December 9-10th 1993 . This workshop attracted favourable comment from the industry and copies of several papers were published in the May edition of Queensland Fisherman.

We concluded that the way the crabs are currently being handled on boats is too stressful. Physiological studies show that spanner crabs, like other oceanic crabs, are not well equipped to survive in air. Yet even if you store them cold on the boat they still die after a few days in tanks on shore. This mortality is an impediment to the maturity of the industry. The crabs may be succumbing to bacterial infections caused by injury and we recommend that their claws are immobilised by banding after capture.

Environment
PROJECT NUMBER • 2020-036
PROJECT STATUS:
COMPLETED

Identifying population connectivity of shark bycatch species in NT waters

Charles Darwin University and the Northern Territory (NT) Department of Industry, Tourism and Trade (DITT) Fisheries Division used genetic data to investigate the population structure of two small tropical shark species (Milk Shark [Rhizoprionodon acutus] and Australian Blackspot Shark [Carcharhinus...
ORGANISATION:
Charles Darwin University (CDU)

Long-term abundance index for goldband snapper in the Timor Sea - A pilot study

Project number: 1994-155
Project Status:
Completed
Budget expenditure: $67,859.85
Principal Investigator: David Ramm
Organisation: Department of Agriculture and Fisheries (NT)
Project start/end date: 29 Mar 1995 - 30 Mar 1997
Contact:
FRDC

Objectives

1. Develop techniques for obtaining repeatable indicies of relative abundance for goldband snapper (Pristipomoides spp.), and other selected groundfish, applicable to habitats commonly found in the Timor Sea including the Timor Box
2. Obtain additional information on the spatial and seasonal distribution of goldband snapper and other groundfish in the Timor Sea
Environment
PROJECT NUMBER • 2014-032
PROJECT STATUS:
COMPLETED

Improved understanding of Tasmanian harmful algal blooms and biotoxin events to support seafood risk management

The 2012 Tasmanian biotoxin event represents a paradigm shift for seafood risk management in Tasmania and Australia as a whole. The causative dinoflagellates are extremely difficult to identify by routine plankton monitoring, and are toxic at very low cell concentrations (50-100 cells/L). Sampling...
ORGANISATION:
University of Tasmania (UTAS)
Environment
PROJECT NUMBER • 2001-253
PROJECT STATUS:
COMPLETED

Aquafin CRC - SBT Aquaculture Subprogram: a risk assessment of factors influencing the health of farmed southern bluefin

The rapidly developing international tuna aquaculture industry started with a joint Japan/ Australia experiment in 1991. Since then it has grown into the largest finfish aquaculture in Australia with an export value of $290 million. It is based on the capture of wild fish and subsequent fattening of...
ORGANISATION:
University of Tasmania (UTAS)
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