Observer-based survey of by-catch from prawn trawling in Botany Bay and Port Jackson, New South Wales

1996 ◽  
Vol 47 (7) ◽  
pp. 877 ◽  
Author(s):  
GW Liggins ◽  
SJ Kennelly ◽  
MK Broadhurst

Catches and by-catches were surveyed in the commercial prawn trawl fleets of Botany Bay and Port Jackson, two estuaries in the Sydney metropolitan area (NSW, Australia). Catches were surveyed in all tows during replicate fishing trips in each month during the 1990-91 and 1991-92 prawn trawl seasons in each estuary. Significant species-specific variabilities in abundances were detected between estuaries, between years, and between early and late in the fishing season. The mean annual ratio of by-catch to catch of prawns (by weight) was 2.5 : 1 for Botany Bay and 1.8 : 1 for Port Jackson. A mean annual by-catch (� 1 s.e.) of 142 � 14 t was taken from the Botany Bay fishery and 38 � 3 t from Port Jackson. These by-catches included large numbers of small recreationally and commercially important finfish: a mean annual by-catch of 1.52 �0.20 million fish from Botany Bay and 219� 23 thousand fish from Port Jackson. Despite uncertainties about the impacts of such by-catches on interacting commercial and recreational fisheries, it is recommended that strategies for the reduction of such by-catches be considered.

1995 ◽  
Vol 46 (4) ◽  
pp. 745 ◽  
Author(s):  
MK Broadhurst ◽  
SJ Kennelly

In response to claims that fish trawls off New South Wales, Australia, caught excessive quantities of under-size fish, the catches of finfish by a conventional fish trawl (constructed of 90-mm mesh in the body) were compared with those by a fish trawl constructed of 100-mm mesh in the body. Catches by the 100-mm trawl showed a 27% reduction in all by-catch and a 28% reduction in the numbers of retained tiger flathead, compared with catches by the conventional trawl. The 100-mm trawl also showed a 48% and 47% reduction in the numbers and weights respectively of discarded tiger flathead and a 57% and 63% reduction in the numbers and weights respectively of discarded rubberlip morwong. For john dory, however, at a particular locality where large numbers occurred, the 100-mm trawl caught significantly more fish than did the conventional trawl (a mean increase in weight of 66%). There is a need to determine species-specific mesh selectivities and to study the behaviour of fish in trawls. The importance of the results for the future management and operational efficiency of trawl fisheries is discussed.


2001 ◽  
Vol 52 (7) ◽  
pp. 987 ◽  
Author(s):  
Charles A. Gray

Observer-based estimates of the catches and by-catches from prawn seining (locally termed ‘snigging’) in Tuggerah Lake (NSW, Australia) during the 1998/99 fishing season are presented. Observed catches included three species of penaeid prawns, while observed by-catches contained a total of 49 finfish and 5 invertebrate taxa. The overall by-catch:prawn catch ratio by weight was 0.9:1, and in catching an estimated 20 ± 4 t of prawns the fleet took an estimated total by-catch of ± 2 t throughout the 6-month fishing season. The by-catch included large numbers of small (<15 cm total length) finfish species important in other commercial and recreational fisheries, including Gerres subfasciatus,Rhabdosargus sarba and Acanthopagrus australis, as well as several small demersal species of little economic value. Multivariate analyses indicated that by-catch composition differed between seines taken over shallow seagrass and bare substrata, with catch rates of several species being greater over seagrass. It is recommended that strategies to reduce potential ecological impacts and by-catch in this fishery be investigated, including fixed spatial closures over seagrasses and the development of alternative fishing gears and practices.


2017 ◽  
Vol 25 (5) ◽  
pp. 456-459
Author(s):  
Kevin Rourke ◽  
Coralie J Wilson

Objectives: To determine if adolescents perceive community-based exercise as beneficial to their well-being and in what ways. Methods: A New South Wales Police Citizens Youth Club ran a four-week fitness course. The classes involved: 1) sports including basketball and soccer, 2) non-contact boxing drills, and 3) games, both team games such as dodgeball and non-team games such as line tag. Parental consent to offer a survey at the completion of the course was requested during registration. The survey was the Warwick Edinburgh Mental Well-being Scale; it was minimally modified to measure perceived benefit to mental well-being instead of actual benefit. Results: Thirty-one high school adolescents, ages 13–18, completed the survey. As a group, participants reported that they believed their well-being had improved after the course. The mean score for each survey item showed an improvement in every area of mental well-being for this sample of adolescents. Thirty-two per cent of adolescents reported having less energy. Survey scores indicated a statistically significant improvement in perceived well-being ( p<0.0001). Conclusions: The results of this study suggest that four weeks of community-based exercise improves perceived mental well-being in adolescent participants.


2000 ◽  
Vol 22 (1) ◽  
pp. 44 ◽  
Author(s):  
SJ Holdaway ◽  
PC Fanning ◽  
DC Witter

Recent erosion in arid regions of western NSW has exposed large areas that are scattered with stone artefacts manufactured by Aboriginal people in prehistory. These exposures offer an opportunity for archaeologists to study the artefacts abandoned by Aboriginal people through time and to compare those artefacts that accumulate in different parts of the landscape. To reconstruct the nature of prehistoric behaviour in the rangelands, two approaches are needed. First, the geomorphological context of the artefacts needs to be considered since exposure of the artefacts is a function of landscape history. Second, large areas (measured in thousands of square metres) and large numbers of artefacts need to be considered if patterns reflecting long-term abandonment behaviour by Aboriginal people are to be identified. This paper reports on the Western New South Wales Archaeological Program (WNSWAP) which was initiated in 1995 to study surface archaeology in the rangelands. Geomorphological studies are combined with artefact analysis using geographic information system software to investigate Aboriginal stone artefact scatters and associated features such as heat retainer hearths, in a landscape context. Results suggest that apparently random scatters of stone artefacts are in fact patterned in ways which inform on prehistoric Aboriginal settlement of the rangelands. Key words: Aboriginal stone artefacts; rangelands; landscape archaeology; geomorphology; GIs


2017 ◽  
Vol 68 (2) ◽  
pp. 207 ◽  
Author(s):  
V. Raoult ◽  
V. Peddemors ◽  
J. E. Williamson

Two species of angel shark (Squatina australis, S. albipunctata) and two species of sawshark (Pristiophorus nudipinnis, P. cirratus) are frequently caught in south-eastern Australia. Little is known of the biology of these elasmobranchs, despite being caught as secondary target species in large numbers. The present study collected morphometric and reproductive data from sharks caught in shark-control nets, commercial fishing trawlers and research trawlers in south-eastern Australia. All four species had female-biased sexual size dimorphism, but growth curves between sexes did not differ. Male S. australis individuals were fully mature at ~800-mm total length, male P. nudipinnis at ~900mm, and male P. cirratus at ~800mm. Anterior pectoral margins could be used to determine total length in all species. No morphometric measurement could reliably separate Squatina spp. or Pristiophorus spp., although S. albipunctata over 1000-mm total length had larger eyes than did S. australis.


1998 ◽  
Vol 46 (2) ◽  
pp. 153 ◽  
Author(s):  
Damon L. Oliver

The regent honeyea ter, Xanthomyza phrygia, is an endangered woodland bird whose range and population size have decreased in the last thirty years. Suggested reasons for this decline include abnormal breeding behaviour, poor reproductive output, and excessive inter- and intra-specific aggression. This study investigated the breeding behaviour and aggressive interactions of regent honeyeaters during the nest construction, incubation, nestling, and fledgling stages in two consecutive breeding seasons in the Bundarra–Barraba region near Armidale, New South Wales. The female was entirely responsible for nest construction and incubation, which is typical of many honeyeaters. Both parents fed the nestlings, and at a similar rate, although only the female brooded chicks on the nest. Both parents fed the fledglings. The mean frequency at which nestlings (23 times per hour) and fledglings (29 times per hour) were fed is the highest published rate of any non-cooperative honeyeater. Breeding males were involved in significantly more aggressive interactions with conspecifics and other nectarivores than were females, although the overall percentage of day-time spent in aggression for both sexes was low (2.5%). It appears that abnormal breeding behaviour, poor reproductive effort, or excessive aggression are not experienced by this species in northern New South Wales, and that other factors are likely to be responsible for its current low population level.


2013 ◽  
Vol 4 (1) ◽  
pp. 38-48
Author(s):  
Laura Olcelli

Tuscan-born and Spanish-trained Alessandro Malaspina (1754-1810) captained the most significant scientific expedition ever launched by Spain in the years 1789-1794. After a survey of the Spanish colonies in America, he directed the course of the Descubierta towards the South Pacific and anchored at Port Jackson on 11 March 1793. In my essay I will scrutinize the New South Wales leg of Malaspina’s voyage account, comparing 'Viaje político-científico alrededor del mundo' (the original 1885 Spanish edition) and 'Journal of a Voyage by Alejandro Malaspina' (its 2001 English translation), and integrating them with the captain’s secret reports. The examination of Malaspina’s comments on the infant colony will simultaneously expose the Spanish attitude to early British colonialism in New South Wales, and help assess Malaspina’s complex role as the first explorer who reached Terra Australis from the Italian peninsula.


1956 ◽  
Vol 4 (2) ◽  
pp. 111 ◽  
Author(s):  
JH Calaby

The little-known Australian genus, Ahamitermes, contains four described species: A. nidicola Mjoberg (Queensland), A. hillii Nicholls (south-western Australia), A. inclusus Gay (restricted to a small sub-coastal area in mid- Western Australia), and A. pumilus (Hill) (New South Wales and Western Australia). Many new distribution records of A. hillii and some of A. inclusus are given. New observations on the biology of Ahamitermes show that the various species have a species-specific parasitic nesting relationship with either one of two species of the genus Coptotermes. They live in specific parts of the inner sections of Coptotermes nests, utilizing as food the carton composing these sections, and are thus dependent on the host for food and shelter. They are not found in any other situation. The nests of host and parasite are separated and the two species are mutually hostile. A. pumilus differs from its congeners in that it is also dependent on the host for the release of its alates which are tolerated inquilines in the host's nest. Termite associations in general and that of Ahamitermes and Coptotermes in particular are discussed.


1994 ◽  
Vol 34 (1) ◽  
pp. 33 ◽  
Author(s):  
GM Lodge

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.


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