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

Technical Annual Report 2000/01 Catch per unit effort (CPUE) remained stable during the period 1990-1993 averaging 5 kg per hook day. This increased to an average of 12 kg per hook day during the period 1994-1997 and has further increased in 1998, 1999 and 2000 to 22.7, 25 and 34.2 kg per hook day, respectively. Patterns such as these may indicate an increase in fishery production brought about by favourable environmental conditions. If this were the case the commercial catch composition should demonstrate increases in catch for all species, as they become more abundant (Figure 2). Analysis of the Coastal Line Fishery catch composition indicates that the 56% increase in total catch from 1999 to 2000 can be directly attributed to one species, the black jewfish. The total catch for this species almost doubled over the 20-month period, increasing from 58 tonnes to 101 tonnes. In 1990 black jewfish contributed only 11% to the total catch and this has increased to 67% in 2000. Golden snapper catches have however remained relatively stable at approximately 12% of the total catch over this same period. F B f a s S b je 2 C c le A s q R F e e a 160 267 igure 2. Catch by major species in the NT coastal line fishery 1983 2000 lack jewfish form large aggregations; however the function of this behaviour is currently unknown. Other ish species often aggregate in inshore areas to spawn. High levels of fishing mortality imposed on such ggregations are not sustainable; however such an outcome highly depends on the spatial and temporal cales at which fishing mortality is applied. imilar concerns raised in north Queensland prompted a recently completed study where target fishing of lack jewfish aggregations was examined. This work has documented the absence of sexually mature black wfish from the study area as well as a significant and rapid reduction in size of fish harvested (Phelan et al. 001 in press). ommercial fishing continues to be based around major population centres. Over 90 percent of the total atch is taken from the greater Darwin region, five percent from the Nhulunbuy/Groote Eylandt regions and ss than one percent from the Borroloola region. ll catch taken to date by the coastal line fishery is by line, resulting in negligible interaction with threatened pecies such as dugong or turtle. All fish species permitted to be taken by this fishery are of good eating uality and are therefore highly marketable. ecreational ishing within the coastal strip adjoining the NT out to 15 nm, including the estuarine systems, provides an xtremely popular fishing area for a large number of anglers targeting species such as jewfish, snappers, mperors, cod, bream and pelagic species such as trevally and queenfish. Species caught by recreational nglers vary significantly depending on area fished, time of year and state of the tide. 0 20 40 60 80 100 120 140 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 T o ta l C at ch ( to n n es ) OTHER SHARK-GENERAL SNAPPER-GENERAL MIXED FISH REEF FISH TRICKY SNAPPER GOLDEN SNAPPER JEWFISH