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.

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.

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.

scholarly journals Comparative Angler Catches of Australian Bass (Macquaria novemaculeata) in Three Major River Systems in New South Wales, Australia

2005 ◽  
Vol 18 (2) ◽  
Author(s):  
B. VAN DER WALT ◽  
R. A. FARAGHER ◽  
J. HARRIS
Keyword(s):  
Time Series Data ◽  
New South ◽  
New South Wales ◽  
River System ◽  
Size Composition ◽  
Series Data ◽  
Severe Drought ◽  
Catch Per Unit Effort ◽  
South Wales ◽  
Catch Rates

A joint program between New South Wales Fisheries and three fishing clubs was initiated in 1988 with the aim of collecting standardised catch and effort data during biannual fishing competitions on three major rivers in New South Wales. This paper examines the data to determine trends in the catch of the target species, Australian bass (Macquaria novemaculeata) and to evaluate whether the data can be used to assess Australian bass populations over time. Distinct trends in Australian bass mean length in each river system were evident but catch rates were more variable. Median catch per unit effort was similar (mostly between 0.5 and 1.5 Australian bass·h-1 ) in the Nepean and Williams Rivers although catch rates in the Manning River were nearly always zero. There was an increasing trend in the mean length of Australian bass in all three rivers, possibly representing a recovery in fish populations following severe drought from 1979 to 1983. Low or zero catch rates were continually recorded in the Manning River and size composition data indicated a lack of recruitment through most of the study period. The standardised format of the data collection program provided qualitative and reliable time series data allowing the determination of long-term trends in the population structure of Australian bass which can be used for monitoring and management purposes.

scholarly journals Quantitative diet assessment of wobbegong sharks (genus Orectolobus) in New South Wales, Australia

2007 ◽  
Vol 64 (6) ◽  
pp. 1272-1281 ◽  
Author(s):  
Charlie Huveneers ◽  
Nicholas M. Otway ◽  
Susan E. Gibbs ◽  
Robert G. Harcourt
Keyword(s):  
Trophic Level ◽  
New South ◽  
New South Wales ◽  
Stomach Contents ◽  
Scuba Diving ◽  
Trophic Levels ◽  
Adult Size ◽  
Interspecific Differences ◽  
South Wales ◽  
Diet Assessment

Abstract Huveneers, C., Otway, N. M., Gibbs, S. E., and Harcourt, R. G. 2007. Quantitative diet assessment of wobbegong sharks (genus Orectolobus) in New South Wales, Australia. – ICES Journal of Marine Science, 64: 1272–1281. The diets of three species of wobbegong (Orectolobus ornatus, O. maculatus, and O. halei) in New South Wales, Australia, were investigated using stomach contents from specimens caught by commercial fishers. Some 80% of wobbegongs caught by commercial setline, and 60% caught by trap or scuba diving, had empty stomachs, most likely due to regurgitation. Wobbegongs were frequently hooked in the stomach (80–90% of the catch), potentially contributing to the greater proportion of empty stomachs compared with other species of shark. The diet of all three species was primarily osteichthyans, but with some cephalopods and chondrichthyans. Interspecific differences in the diets were related to total length of the shark. Octopuses were more frequent in the diet of O. ornatus (dwarf ornate wobbegong) than other wobbegong species, possibly through the smaller adult size facilitating capture of octopuses in small holes/crevices. Orectolobus halei fed more frequently on pelagic species and chondrichthyans, possibly because of their greater mobility. Wobbegongs feed at a high trophic level, and their removal from their ecosystem may impact lower trophic levels.

The New South Wales Trawlfishery: Review of Past Course and Examination of Present Condition

1955 ◽  
Vol 6 (2) ◽  
pp. 165 ◽  
Author(s):  
TW Houston
Keyword(s):  
New South ◽  
New South Wales ◽  
Size Composition ◽  
Fishing Effort ◽  
Present Condition ◽  
Catch Per Unit Effort ◽  
Nineteen Thirties ◽  
Unit Effort ◽  
South Wales ◽  
Post War

The past course of the New South Wales mixed trawlfishery is reviewed mainly on the basis of the available catch and fishing effort statistics. The size composition of tiger flathead landings from 1946-47 to 1953-54, and the age composition for certain post-war years, are analysed in conjunction with catch per unit effort data. The results suggest that 1943-44, 1944-45, 1947-48, and 1948-49 were relatively poor brood years, and 1945-46 and 1946-47 relatively good. The fluctuations in availability of tiger flathead (Neoplatycephalus macrodon (Ogilby) ) are accounted for after making certain valid assumptions. It is considered probable that the unexpectedly low catches of tiger flathead in the immediate post-war years were due to inefficiency of the few steam trawlers then working, and that Danish seiners were unable to exploit fully the available V+ and higher age-group fish. An examination of the present situation indicates that the New South Wales stock of tiger flathead is at a low level and is likely to reach even lower levels in the future if fishing intensity remains as high as in 1953-54. An improvement of the existing catch per unit effort would be expected if fishing intensity was reduced to the level of the middle nineteen-thirties (i.e. approx. 3500 trawler-tons) . Other regulative measures would need to be introduced to bring about an improvement in the annual catch of tiger flathead. These measures should aim at ensuring a more favourable weight-length relation.

An assessment of pedoturbation by two species of mound-building ants, Camponotus intrepidus (Kirby) and Iridomyrmex purpureus (F. Smith)

Soil Research ◽  
1985 ◽  
Vol 23 (1) ◽  
pp. 95 ◽  
Author(s):  
JA Cowan ◽  
GS Humphreys ◽  
PB Mitchell ◽  
CL Murphy
Keyword(s):  
Impact Energy ◽  
Organic Material ◽  
Size Structure ◽  
New South ◽  
New South Wales ◽  
Size Composition ◽  
Soil Mixing ◽  
South Wales ◽  
Erosion Protection ◽  
Raindrop Impact

Details of the size, structure and occurrence of Carnponotus intrepidus nests and the size, composition and source of the mound cover on Iridomyrmex purpureus nests are reported from several areas of eastern New South Wales. Both species are common, and construct large mounds of mixed topsoil and subsoil with surface covers, which appear to protect the mound from rainsplash erosion. Camponotus thatches the mound with charcoal, leaves and twigs; Iridomyrmex covers the mound in granules of inorganic or organic material that are sufficiently large to absorb most raindrop impact energy. This material is collected from the surface and carried 10-15 m to the nest. Rainsplash erosion protection is probably a factor contributing to nest longevity, which may be as much as 100 years for Iridomyrmex. It is concluded that, despite the impressive size of the nests and the selective use of materials, neither species is very significant in terms of soil mixing when compared with the smaller, more common ant Aphaenogaster longiceps.

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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