Condition index and chemical composition of meats of Sydney rock oysters (Saccostrea commercialis) and Pacific oysters (Crassostrea gigas) at four sites in Port Stephens, NSW

1995 ◽  
Vol 46 (5) ◽  
pp. 873 ◽  
Author(s):  
CJ Mason ◽  
JA Nell
Keyword(s):  
Crassostrea Gigas ◽  
Histological Analysis ◽  
New South ◽  
Condition Index ◽  
Absolute Amount ◽  
Pacific Oysters ◽  
South Wales ◽  
Condition Indices ◽  
A Site ◽  
Port Stephens

Adult Sydney rock oysters (Saccostrea commercialis) and Pacific oysters (Crassostrea gigas) were kept on commercial oyster leases at three intertidal sites in Port Stephens, New South Wales, and subtidally under an experimental raft at a fourth site between July 1988 and September 1989. Oysters were sampled from each site at approximately monthly intervals for chemical and histological analysis. Condition index and percentage glycogen of Pacific oysters were higher than those of Sydney rock oysters during winter and spring but tended to be lower during summer and autumn. Gonads of Pacific oysters matured two months earlier than those of Sydney rock oysters, with spawning being observed at all sites in October. Sydney rock oysters spawned later during December-January and did not lose as much condition after spawning as Pacific oysters. The absolute amount of glycogen in the meats of both species dropped at the expense of protein and lipid as the oysters became fully ripe. For both species, general condition of the oysters was best when they were grown subtidally under the raft, although both species were badly affected by invasion of the protistan parasite Mikrocytos roughleyi at this site. Poorest overall condition for both species occurred at a site (Karuah River) that experienced decreased salinities and increased turbidity after rain. Highest condition indices were found in Sydney rock oysters, at the site most dominated by coastal conditions (Corrie Island).

Mass mortalities of unknown aetiology in Pacific oysters Crassostrea gigas in Port Stephens, New South Wales, Australia

2017 ◽  
Vol 125 (3) ◽  
pp. 227-242 ◽  
Author(s):  
J Go ◽  
AT Deutscher ◽  
ZB Spiers ◽  
K Dahle ◽  
PD Kirkland ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
New South ◽  
New South Wales ◽  
Unknown Aetiology ◽  
Pacific Oysters ◽  
South Wales ◽  
Mass Mortalities ◽  
Port Stephens

Change in wild-oyster assemblages of Port Stephens, NSW, Australia, since commencement of non-native Pacific oyster (Crassostrea gigas) aquaculture

2010 ◽  
Vol 61 (6) ◽  
pp. 714 ◽  
Author(s):  
Melanie J. Bishop ◽  
Fredrick R. Krassoi ◽  
Ross G. McPherson ◽  
Kenneth R. Brown ◽  
Stephen A. Summerhayes ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
New South ◽  
Shell Height ◽  
Larval Transport ◽  
South Wales ◽  
Circulation Patterns ◽  
Fouling Assemblages ◽  
Native Oyster ◽  
Port Stephens

Proliferation of species introduced for aquaculture can threaten the ecological and economic integrity of ecosystems. We assessed whether the non-native Pacific oyster, Crassostrea gigas, has proliferated, spread and overgrown native Sydney rock oysters, Saccostrea glomerata, in Port Stephens, New South Wales (NSW), Australia, following the 1991 decision to permit its aquaculture within this estuary. Sampling of seven rocky-shore and four mangrove sites immediately before (1990), immediately after (1991–1992) and nearly two decades after (2008) the commencement of C. gigas aquaculture did not support the hypotheses of C. gigas proliferation, spread or overgrowth of S. glomerata. The non-native oyster, uncommon immediately before the commencement of aquaculture, remained confined to the inner port and its percentage contribution to oyster assemblages generally declined over the two decades. C. gigas populations were dominated by individuals of <40-mm shell height, with established adults being rare. Only at one site was there an increase in C. gigas abundance that was accompanied by S. glomerata decline. The failure of C. gigas in Port Stephens to cause the catastrophic changes in fouling assemblages seen elsewhere in the world is likely to reflect estuarine circulation patterns that restrict larval transport and susceptibility of the oysters to native predators.

Models of the distribution and abundance of ground-dwelling mammals in the eucalypt forests of north-eastern New South Wales in relation to environmental variables

2002 ◽  
Vol 29 (3) ◽  
pp. 313 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt ◽  
R. I. Forrester
Keyword(s):  
Environmental Variables ◽  
New South ◽  
New South Wales ◽  
Slope Position ◽  
Slope Aspect ◽  
Significant Variable ◽  
South Wales ◽  
North Eastern ◽  
Eucalypt Forests ◽  
A Site

Statistical models are presented of the distribution and abundance of ground-dwelling mammals in eucalypt forests in relation to environmental variables within an area of approximately 24 000 km2 in north-eastern New South Wales. Environmental variables are defined as climatic or topographic variables that may be useful to map the distribution of fauna. The environmental variables examined were season, temperature, rainfall, elevation, lithology, steepness of slope, position on slope, aspect and landform profile. The probability of recording some species was higher in spring than autumn and many species were in highest abundance in areas of low temperature (high elevation). Although aspect was a significant variable in a number of models, no species was absent from any aspect category. Mid-slopes down to and including creeks and drainage lines were particularly important for many species, as were areas with flatter terrain. Although we have modelled environmental variables only there will no doubt be longer-term interactions between habitat and environmental variables. Fundamentally, environmental variables will determine the type of habitat present at a site, and the distribution of canopy communities, at least, can be predicted from environmental variables. However, other studies have shown for ground-dwelling mammals that environmental variables contribute little and it is the state of the habitat locally, and particularly the understorey, that determines their presence and abundance at a site. The results are discussed in relation to similar models using habitat variables and in relation to the use of such models in the management of ground-dwelling fauna in forests.

Accumulation of Tributyltin by the Sydney Rock Oyster, Saccostrea commercialis

1989 ◽  
Vol 40 (1) ◽  
pp. 49 ◽  
Author(s):  
GE Batley ◽  
C Fuhua ◽  
CI Brockbank ◽  
KJ Flegg
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
New South ◽  
New South Wales ◽  
Tidal Flushing ◽  
Rock Oyster ◽  
South Wales ◽  
The Pacific

Tributyltin (TBT) concentrations have been measured in the tissue of the Sydney rock oyster Saccostrea commercialis sampled from estuaries in New South Wales, Australia. Background TBT levels of below 2 ng Sn g-1 contrasted with values between 80 and 130 ng Sn g-1 in oysters exposed to high boat densities or poor tidal flushing. Shell deformities and reduced tissue weights were associated with all samples displaying elevated TBT levels. Specimens of the Pacific oyster, Crassostrea gigas, growing on the same racks displayed 2-3 times the TBT concentrations of S. commercialis.

Lake Mungo

1985 ◽  
Vol 13 (2) ◽  
pp. 27-31 ◽  
Author(s):  
Barry Wright
Keyword(s):  
Everyday Life ◽  
Health Worker ◽  
Aboriginal People ◽  
New South ◽  
New South Wales ◽  
Aboriginal Health ◽  
Aboriginal Child ◽  
South Wales ◽  
A Site ◽  
Aboriginal Health Worker

Lake Mungo, in New South Wales, is the home of the first known people in this country. Here, the oldest known evidence of Aboriginal people in Australia has been found. Because of its importance, it is a site which everyone should know about. To give us a feeling for Lake Mungo, Billy Reid, the illustrator of The Aboriginal Health Worker and The Aboriginal Child at School, came with me on a trip. We travelled west to the Darling River (whose Aboriginal name is Calewatta), and then south-east to Lake Mungo itself. Billy made wonderful drawings to represent the deeds and everyday life of those people. This can be reconstructed from the fossil evidence found at Lake Mungo. He has also drawn some scenes of life along the banks of the Calewatta - the river which is Billy’s own home. He hails from Bourke.

Large-scale patterns in habitat structure on subtidal rocky reefs in New South Wales

2000 ◽  
Vol 51 (3) ◽  
pp. 255 ◽  
Author(s):  
N. L. Andrew ◽  
A. L. O'Neill
Keyword(s):  
Sea Urchin ◽  
Geographical Information Systems ◽  
Large Scale ◽  
Size Structure ◽  
New South ◽  
New South Wales ◽  
Geographical Information ◽  
South Wales ◽  
Subtidal Rocky Reefs ◽  
A Site

Aerial photography was used to estimate the representation of shallow subtidal habitats in New South Wales. Sixty sites, each between 4 and 5 hectares, were mapped with Geographical Information Systems software using ortho-rectified images digitized from 1:8000-scale photographs and ‘ground truthed’ in the field by divers. Barrens habitat covered an estimated 50% (s.e. = 3.9) of nearshore reefs between Port Stephens and Disaster Bay. Coverage of barrens habitat was greatest in Disaster Bay (68%, s.e. = 6.7) and least south of Disaster Bay (1%, s.e. = 0.3). There were clear differences among localities in the area of reef within the mapped sites; those at Cape Howe, Nadgee, and Turingal were significantly smaller in area than all others. There was no clear latitudinal trend in these differences but there was evidence of sand inundation at a site at Nadgee, where the reef was small. Differences in the densities and size-structure of the sea urchin Centrostephanus rodgersiiat 27 of the mapped sites provide a basis for testing relationships between the demography of this species and the persistence of the barrens habitat. The extensive coverage of the barrens habitat in New South Wales is likely to limit the productivity of the abalone industry. The development of a sea urchin fishery may have large impacts on habitat representation on nearshore reefs.

1080 aerial baiting for the control of wild dogs and its impact on spotted-tailed quoll (Dasyurus maculatus) populations in eastern Australia

2007 ◽  
Vol 34 (1) ◽  
pp. 48 ◽  
Author(s):  
G. Körtner
Keyword(s):  
New England ◽  
New South ◽  
Mortality Rates ◽  
Fresh Meat ◽  
South Wales ◽  
Eastern Australia ◽  
History Of ◽  
A Site ◽  
Wild Dogs ◽  
Test Result

To further investigate the non-target impact of baiting using sodium monofluoroacetate (compound 1080) to control wild dogs, a population of radio-collared spotted-tailed quolls was subject to an experimental aerial baiting exercise. The trial was conducted at a site on the New England Tablelands, New South Wales, without a recent history of that practice. Sixteen quolls were trapped and radio-collared before baiting. Fresh meat baits were delivered from a helicopter at a rate of 10–40 baits km–1. In addition to 1080 (4.2 mg), each bait contained the bait marker rhodamine B (50 mg), which becomes incorporated into growing hair if an animal survives bait consumption. Two quoll mortalities were recorded following aerial baiting. Both quolls died 3–5 weeks after baiting when baits, on average, retained little 1080. None of the carcasses contained traces of 1080, but the test result is less reliable for the quoll that was found 19 days after its death although tissue was well preserved because of the cool weather. Nevertheless, given that this animal died 34 days after bait delivery, it appears likely that none of the radio-collared quolls succumbed to baiting. In contrast, vibrissae samples collected from 19 quolls captured after the baiting showed that 68% had eaten baits and survived. Furthermore, multiple bait takes were common, with up to six baits consumed by one female. The results demonstrate that most, if not all, quolls survived the baiting trial, including those that consumed dog baits. Hence bait consumption figures per se are not indicative of mortality rates attributable to poisoning.

The contribution of the community to defining the distribution of a vulnerable species, the spotted-tailed quoll, Dasyurus maculatus

2001 ◽  
Vol 28 (5) ◽  
pp. 537 ◽  
Author(s):  
Daniel Lunney ◽  
Alison Matthews
Keyword(s):  
Field Survey ◽  
New South ◽  
New South Wales ◽  
Vulnerable Species ◽  
Community Based ◽  
Private Lands ◽  
Survey Techniques ◽  
European Settlement ◽  
South Wales ◽  
Port Stephens

Community-based wildlife postal surveys, which included the spotted-tailed quoll, were undertaken in Eden, Port Stephens, Bellingen and Iluka. This resulted in 68 records for spotted-tailed quolls for Eden, 40 for Port Stephens, 39 for Bellingen and 7 for Iluka. Such a high number of records from coastal New South Wales, with many on private lands, identifies postal surveys as a major source of previously overlooked sightings. Spotted-tailed quolls have declined in range by as much as 50–90% since European settlement, which has seen them listed as a nationally vulnerable species. There have been few surveys of spotted-tailed quolls in New South Wales due to their difficulty of detection using standard field survey techniques, such as cage trapping and hair tube sampling. Their unique appearance makes them an ideal species to include in community-based surveys. Future use of these surveys has the potential to contribute significantly to conservation programs of spotted-tailed quolls that involve private lands and local support.

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