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

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).

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.

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.

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.

The impact of fire and dogs on Koalas at Port Stephens, New South Wales, using population viability analysis

2007 ◽  
Vol 13 (3) ◽  
pp. 189 ◽  
Author(s):  
Danial Lunney ◽  
Shaan Gresser ◽  
Lisa E. O'neill ◽  
Alison Matthews ◽  
Jonathan Rhodes
Keyword(s):  
New South ◽  
Local Population ◽  
New South Wales ◽  
Population Viability Analysis ◽  
Population Viability ◽  
Phascolarctos Cinereus ◽  
Viability Analysis ◽  
South Wales ◽  
The Impact ◽  
Port Stephens

The Port Stephens Koala Phascolarctos cinereus population has been regarded as one of the strongholds for Koalas in New South Wales. This study applied population viability analysis to investigate the impact of fire and predation by dogs on the viability of the local population. The rapid decline of the modelled Koala population under basic assumptions throws the assumed security of such large populations into question. In all the modelled management scenarios, reducing mortality had more influence than any other factor. Reducing the severity and frequency of large catastrophic fires improved the probability of survival for the population, though the modelled population size still declined sharply. Any management action to improve Koala survival must be accompanied by a reduction in mortality from dog attacks. Fires and dogs will have an ever greater impact on Koala populations as coastal forests become more fragmented and isolated by urban development, and their combined control will be needed to complement land-use planning measures to address habitat loss and fragmentation.

Range extension and first occurrence of the thorny seahorse Hippocampus histrix in New South Wales, Australia

2015 ◽  
Vol 8 ◽  
Author(s):  
D. Harasti
Keyword(s):  
East Coast ◽  
New South ◽  
New South Wales ◽  
Range Extension ◽  
South Wales ◽  
First Occurrence ◽  
Port Stephens

Between 2007 and 2014, three individual thorny seahorses,Hippocampus histrix,were recorded in Port Stephens, New South Wales, Australia. Specimens ranged in size from 6 to 8 cm and were considered to be females. This extends the known range ofH. histrixalong the east coast of Australia by 1700 km.

The tree species preferences of koalas (Phascolarctos cinereus) inhabiting forest and woodland communities on Quaternary deposits in the Port Stephens area, New South Wales

2000 ◽  
Vol 27 (1) ◽  
pp. 1 ◽  
Author(s):  
Stephen Phillips ◽  
John Callaghan ◽  
Valerie Thompson
Keyword(s):  
Tree Species ◽  
New South ◽  
New South Wales ◽  
Eucalyptus Species ◽  
Quaternary Deposits ◽  
Faecal Pellets ◽  
South Wales ◽  
Species Preferences ◽  
Woodland Communities ◽  
Port Stephens

An assessment of the tree species preferences of koalas inhabiting forest and woodland communities growing on Quaternary deposits in the Port Stephens area, New South Wales, was undertaken between November 1994 and March 1996. Using a plot-based methodology, 3847 trees were sampled, comprising 15 Eucalyptus species and 17 species of non-eucalypt. Evidence of tree use by koalas, specifically the presence of koala faecal pellets, was recorded from beneath 10 Eucalyptus species and 9 species of non-eucalypt. Tree species preferences were determined by analyses of log- likelihood ratios derived from data based on the presence/absence of koala faecal pellets, rather than on gross counts. This approach confirmed significant variation in the levels of utilisation amongst and between different tree species, and that two in particular – swamp mahogany (E. robusta) and drooping red gum (E. parramattensis) – were most preferred. Increases in the levels of use of other tree species were also positively associated with the presence of E. robusta and/or E. parramattensis. Levels of utilisation of E. robusta and E. parramattensis did not alter significantly in response to changes in their respective densities, suggesting that the relative abundance of both was important in terms of understanding the carrying capacity of vegetation communities utilised by koalas. The results have established the success with which an enumerative approach to the interpretation of faecal pellet data can be utilised to clarify the tree species preferences of koalas. Application of the approach for habitat assessment and mapping purposes is also discussed.

scholarly journals A 29-year retrospective analysis of koala rescues in New South Wales, Australia

2020 ◽  
Author(s):  
Renae Charalambous ◽  
Edward J. Narayan
Keyword(s):  
Retrospective Analysis ◽  
Cultural Differences ◽  
New South ◽  
New South Wales ◽  
Management Team ◽  
Common Disease ◽  
Induce Stress ◽  
South Wales ◽  
Government Legislation ◽  
Port Stephens

AbstractThe koala (Phascolactos cinereus) is currently listed by both the IUCN and the Australian Governments’ Threatened Species Scientific Committee as vulnerable to extinction with a decreasing population trend. This listing can be attributed to climate change and its impact on ecosystems, and anthropomorphic environmental change due to extensive land clearing and habitat fragmentation. These have both been proven to induce stress, which influences the onset of disease. This novel study performed a retrospective analysis whereby records for 12,543 wild, rescued koalas in New South Wales (NSW), Australia were studied in order to determine trends in koala sightings, clinical admissions and injury diagnoses over a period of 29 years (1989-2018). Results indicated that between all three study locations (Port Stephens, Port Macquarie and Lismore), the most common reason koalas were admitted into care was because of disease, the most common disease diagnosed was signs of chlamydia, and the most common outcome for koalas admitted into care was released. At Port Stephens, mature and female koalas were diagnosed with a disease more than any other age or sex, while juvenile and male koalas were released (back into the wild) more than any other age or sex. Additionally, there were fewer koalas with a disease and fewer koalas released in Port Stephens as each year progressed. At Port Macquarie, mature and male koalas were diagnosed with a disease more than any other age or sex, while juvenile and female koalas were released more than any other age or sex. Additionally, there were more koalas with a disease and fewer koalas released in Port Macquarie as each year progressed. At Lismore, adult and female koalas were diagnosed with a disease more than any other age or sex, while joey and male koalas were released more than any other age or sex. Additionally, there were more koalas with a disease and fewer koalas released in Lismore as each year progressed. Determining trends in clinical admissions and diagnosis over such a substantial period of time is an important factor in preventing the continuing decline of koalas throughout Australia, and in particular NSW. It is important to note that there are cultural differences between koala rescue groups in the three study locations (Port Stephens, Port Macquarie and Lismore). These differences may be reflected in the outcomes of koala patients as each group are driven by their own management team. It is essential that any further decline of koala populations is prevented, however this can only be achieved through informed recommendations through research studies such as these. These recommendations should lead to government legislation which can provide stronger protection to koala habitat.

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