Territory Stories

Technical annual report 2000-01

Details:

Title

Technical annual report 2000-01

Collection

Dept. of Regional Development, Primary Industry, Fisheries and Resources technical annual report; Department of Regional Development, Primary Industry, Fisheries and Resources technical and annual report; Reports; PublicationNT; Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295

Date

2001-10

Description

Made available via the Publications (Legal Deposit) Act 2004 (NT).

Notes

Date:2001-10

Language

English

Subject

Agriculture -- Northern Territory -- Periodicals; Fisheries -- Northern Territory -- Periodicals

Publisher name

Dept. of Primary Industry and Fisheries

Place of publication

Darwin

Series

Technical bulletin (Northern Territory. Dept. of Primary Industry and Fisheries) ; no. 295

ISSN

0158-2763

Copyright owner

Check within Publication or with content Publisher.

Parent handle

https://hdl.handle.net/10070/223369

Citation address

https://hdl.handle.net/10070/687151

Page content

Department of Primary Industry and Fisheries 274 Stock assessment workshops were held in 1996, 1999 and 2000 to provide advice on the status of NT mud crab stocks. Professor Carl Walters, an internationally recognised expert on fisheries matters, led the reviews in 1996 and 2000 and found that based on available data and documented current fishing practices, the fishery although heavily exploited, was unlikely to suffer from recruitment overfishing. Profile of the Fishery: Commercial The fishery is limited to 49 fully transferable licences. Each licence holder is entitled to use a maximum of 60 pots that must comply with specified dimensions and construction materials. Crabbers generally operate from 5 m aluminium dinghies powered by 40 to 130 horsepower, two or four stroke outboard motors, depending on loads and distances travelled. Crabbers may travel in excess of 100 km to set their pots and then often stay in the vicinity for a number of days before returning to their base to unload the catch. Crab pots are baited with fresh meat or fish and set in estuarine and coastal waters. Pots are generally checked on each daylight high tide and on some occasions, if tides and other conditions are favourable, they may be checked again at night using a spotlight. Pots are hand hauled and all crabs are checked for size and degree of fullness. Crabs deemed to be commercially unsuitable are returned to the water at the point of capture. Live mud crabs are stored in moist hessian lined crates and transported to Darwin at least weekly prior to onshipping to interstate and export markets. Most crabbing operations work from small, temporary, basic land-based camps. As yet electronic aids such as radar, sounder or GPS are virtually nonexistent, although HF radio communications are at times used. The by-catch of non-target species is minimal for the mud crab fishery. Crab pots are highly selective towards large mud crabs due to the large mesh size used in their construction. Also the aggressive nature of mud crabs is likely to deter other animals from entering the pot. Commercial crabbers are also in some areas entitled to use a restricted bait net to catch bait specifically for their operation. Target bait species include catfish, blue salmon, shark and mullet. Other species may also be taken in small quantities as an incidental bycatch. The NT Mud Crab Association has recently introduced a code of conduct for the commercial fishery. A number of changes to fishing operations and handling practices were introduced. Of greatest importance was the banning of harvest of empty crabs, now deemed as commercially unsuitable crabs. These are crabs that have recently moulted and have not fully grown into their new shell. Catch and Effort The 2000 NT commercial mud crab catch reached 1,037 tonnes and was valued at approximately $13 million. The Mud Crab Fishery is the most valuable NT wild harvest fishery representing approximately 40% of the total value of NT landings (excluding aquaculture). Catch and effort and CPUE data for the NT mud crab fishery are shown in Figure 1. Catches have continued to increase over the fifteen-year history of the managed fishery and preliminary figures for the year 2001 indicate that this trend is continuing.