Annual total mortality and population stucture of jackass morwong (Nemadactylus macropterus Bloch & Schneider) in eastren Australian waters

1983 ◽  
Vol 34 (2) ◽  
pp. 253 ◽  
Author(s):  
DC Smith
Keyword(s):  
New South ◽  
New South Wales ◽  
Total Mortality ◽  
Natural Mortality ◽  
Trawl Fishery ◽  
South Wales ◽  
Annual Total ◽  
Older Males

Catch curves were analysed to estimate the annual total mortality of jackass morwong landed at the port of Eden between July 1976 and June 1979. The annual total mortality of females was lower in 1978-1979 than in the previous 2 years, reflecting the expansion of the trawl fishery in New South Wales to include previously unexploited deepwater grounds. Males were fully recruited to the commercially exploited population at an earlier age than females. It is suggested that the increased mortality in older males is due to an increase in natural mortality.

Variations in sex, length and age compositions of commercial catches of Platycephalus fuscus (Pisces : Platycephalidae) in New South Wales, Australia

2002 ◽  
Vol 53 (7) ◽  
pp. 1091 ◽  
Author(s):  
C. A. Gray ◽  
V. J. Gale ◽  
S. L. Stringfellow ◽  
L. P. Raines
Keyword(s):  
Average Length ◽  
New South ◽  
New South Wales ◽  
Total Mortality ◽  
Mesh Size ◽  
Growth Zone ◽  
Male Fish ◽  
Age Composition ◽  
South Wales ◽  
By Catch

Commercial landings of dusky flathead (Platycephalus fuscus) from four estuaries in New South Wales (NSW), Australia, were sampled for data on sex, length and age composition between February and July each year for 2–3 years between 1995 and 1997. Landings primarily contained female fish, ranging from 55% to 93% by number for different estuaries. Flathead sampled in commercial catches ranged from 30 cm to 96 cm total length (TL), but the majority were 33–50 cm TL. Fish >40 cm TL were primarily female and male fish >45 cm TL were uncommon. The length composition of catches differed between gillnets of different mesh sizes, with the average length of fish being least in the smallest allowed mesh size of 70 mm. Fish were aged by otolith interpretation and the analysis of marginal increments indicated that one opaque and one translucent growth zone was formed each year; the opaque zone being deposited in June–August (winter) and first observed in September–October (spring). Commercial landings included fish aged 2–11+ years, but fish aged 2–4+ years dominated landings in all estuaries. The total mortality of dusky flathead in each estuary was estimated by catch curve analysis and was relatively high, ranging from 0.45 to 1.64. The data indicate that dusky flathead may be heavily exploited in NSW.

State entrepreneurship in New South Wales’ trawl fishery, 1914-1923

2020 ◽  
Vol 32 (3) ◽  
pp. 636-655
Author(s):  
Lif Lund Jacobsen
Keyword(s):  
New South ◽  
New South Wales ◽  
Consumer Market ◽  
Fish Stocks ◽  
Trawl Fishery ◽  
South Wales ◽  
Policy Goals ◽  
Fisheries Policy ◽  
Economic Failure ◽  
New Consumer

In 1914, the New South Wales (NSW) Government decided to alter its fisheries policy, with the development of an offshore trawling industry supplanting support for inshore fishing as its key development objective. Accordingly, between 1915 and 1923 the NSW Government operated a commercial trawling industry designed to fish previously unexploited fish stocks on the state’s continental shelf. The State Trawling Industry (STI) was designed to meet a mix of social and economic policy goals, with the NSW Government controlling all parts of the production line from catching to selling produce. This article examines the business structure of the enterprise to reveal the reasons for its economic failure. It argues that government entrepreneurship created a new consumer market and unintentionally paved the way for the rise of a modern private trawling industry.

Distribution, population structure and biological aspects of Squalus spp. (Chondrichthyes:Squaliformes) from New South Wales and adjacent Australian waters

2005 ◽  
Vol 56 (4) ◽  
pp. 405 ◽  
Author(s):  
Ken J. Graham
Keyword(s):  
New South ◽  
New South Wales ◽  
Size Composition ◽  
Adult Size ◽  
Mixed Species ◽  
Trawl Fishery ◽  
South Wales ◽  
Female Data ◽  
Biological Aspects ◽  
Upper Slope

Four species of Squalus dogsharks, S. megalops, S. cf. mitsukurii, Squalus sp. B and Squalus sp. F inhabit shelf and upper-slope depths off New South Wales and adjacent Australian states. During fishery surveys between 1976 and 2001, distributional, size composition and reproductive data were collected for these species. Adult size classes dominated catches and, for S. megalops, heavily biased sex ratios were observed. Although no female data were available for the rarely caught Squalus sp. B, reproduction in the other three species was found to be continuous with no evidence of seasonality. Fecundity was 1–3 embryos for S. megalops, 1–5 for Squalus sp. F and 4–10 for S. cf. mitsukurii. All species are commercially exploited, contributing to the mixed species demersal trawl fishery off New South Wales. Stocks of some species are greatly depleted on the main trawling grounds, but the overall distributions of all species include large areas of lightly exploited habitat.

Evidence is required to address potential albatross mortality in the New South Wales Ocean Trawl fishery.

2014 ◽  
Vol 20 (3) ◽  
pp. 328 ◽  
Author(s):  
Eduardo Gallo-Cajiao
Keyword(s):  
New South ◽  
New South Wales ◽  
Mitigation Measures ◽  
Management Agency ◽  
Trawl Fishery ◽  
Responsible Management ◽  
Management Actions ◽  
South Wales ◽  
Legal Obligations ◽  
Trawl Fisheries

To examine the current management of trawl fisheries is important to ensure albatross mortality is not being overlooked. By-catch of albatrosses in trawl fisheries occurs cryptically, which has hindered the development of conservation policy. The implementation of tasked seabird observer programmes in trawl fisheries, nevertheless, has shown that albatross mortality can happen at threatening levels. Consequently, mitigation measures have been developed and adopted in some trawl fisheries. Despite this, some trawl fisheries lack clear policy in relation to albatross mortality. In this context, I investigated the management of potential albatross mortality in a state trawl fishery, the New South Wales Ocean Trawl, in Australia. I conducted a literature search and addressed a set of questions to the responsible management agency through questions on notice at the State Parliament of New South Wales to understand albatross interactions from a policy standpoint. My results indicate that current policy neither encompasses albatross mortality nor is evidence-based. However, the combination of characteristics of this fishery and its overlap with albatross occurrence, along with the reported albatross mortality from other trawl fisheries, may warrant the need to collect empirical evidence on potential albatross interactions. Hence, the responsible management agency should take action according to legal obligations. In this scenario, I recommend the implementation of a tasked seabird observer programme, collection of baseline data, and adoption of adaptive management by the examined fishery. As uncertainty can hamper conservation efforts because management actions require evidence, it is imperative to fill current information gaps in this fishery. Additionally, an improved understanding of albatross mortality from individual trawl fisheries across different fisheries management jurisdictions will enable the prioritization of conservation efforts of this avian taxon in an international and multi-gear fishing context.

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