Distribution of the cyanobacterial toxins cylindrospermopsin and deoxycylindrospermopsin in a stratified lake in north-eastern New South Wales, Australia

2009 ◽  
Vol 60 (1) ◽  
pp. 25 ◽  
Author(s):  
Sally Everson ◽  
Larelle Fabbro ◽  
Susan Kinnear ◽  
Geoff Eaglesham ◽  
Paul Wright

This paper describes the vertical water column distribution of the cyanobacterial toxins cylindrospermopsin and deoxycylindrospermopsin in a water body containing the cyanobacteria Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii. The study site was Cobaki Village Lake, a small stratified anthropogenic lake in north-eastern New South Wales, Australia. Water quality analysis indicated that stratification and oxygenation of the water column were significant in both the distribution of the cyanobacterial populations and their associated toxin concentrations. Toxin was distributed throughout the entire water column, but the highest concentrations were recorded in the hypolimnion. Maximum toxin concentrations were detected in February 2007 (38.2 μg L–1 cylindrospermopsin (CYN) and 42.2 μg L–1 deoxy-CYN). The relative distribution of CYN and deoxy-CYN paralleled the distribution of NH3H and NOX within the water column, with oxygenated chemical species dominating above 15 m and de-oxygenated chemical species dominating below 15 m. Cyanobacterial cell concentrations were highest in the oxic, warm and low conductivity waters of the epilimnion and cyanobacterial species succession was associated with nutrient and trace-metal depletion in this surface layer. These research findings are directly relevant to the management of water supplies affected by toxic blue-green algal blooms, particularly with respect to the considered placement of off-take devices to avoid layers of cyanobacterial cell and toxin concentrations.

2002 ◽  
Vol 106 (1) ◽  
pp. 57-69 ◽  
Author(s):  
R.L Pressey ◽  
G.L Whish ◽  
T.W Barrett ◽  
M.E Watts

2010 ◽  
Vol 2 (5) ◽  
pp. 1378-1399 ◽  
Author(s):  
Clement E. Akumu ◽  
Sumith Pathirana ◽  
Serwan Baban ◽  
Daniel Bucher

2002 ◽  
Vol 29 (3) ◽  
pp. 313 ◽  
Author(s):  
P. C. Catling ◽  
R. J. Burt ◽  
R. I. Forrester

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.


1982 ◽  
Vol 33 (1) ◽  
pp. 77 ◽  
Author(s):  
AH Arthington ◽  
JAL Watson

The Odonata and physicochemical properties of freshwater streams, lakes, ponds and bogs in the sand-dune systems of Fraser, Moreton and North Stradbroke Islands and Cooloola, Queensland: and Wooli, New South Wales, are described. The odonate faunas of these dune masses show some differences from those of nearby areas, and there are close associations between some species and particular types of dune fresh water. Although no physicochemical characteristics were identified that might limit these dune dragonflies to their specific habitats, the lake-dwellers in particular may be useful indicators of environmental change.


2009 ◽  
Vol 31 (2) ◽  
pp. 89 ◽  
Author(s):  
Ian F. Hayes ◽  
Ross L. Goldingay

The vast network of roads around the world has had a significant effect on wildlife and ecosystems through habitat fragmentation, reduced dispersal and mortality by collision with vehicles. Road agencies worldwide now frequently install dedicated structures to facilitate the safe crossing of roads by wildlife. We conducted surveys to determine the use of dedicated wildlife overpasses and nearby underpasses at two locations on the Pacific Highway in north-eastern New South Wales. Road-kill surveys were conducted to provide some understanding of the species commonly killed and whether the rate of road-kill was lower at one location where crossing-structures were located. Use of the crossing-structures by wildlife was monitored with sand-transects. The most frequent users were macropods, bandicoots and rodents. Macropods made greater use of overpasses (n = 104 tracks) than underpasses (n = 36), whereas underpasses were used more by bandicoots (n = 87) and rodents (n = 82) than were overpasses (n = 28, n = 15, respectively). We identified 78 road-kills of 21 species on two sections of the Pacific Highway over a 7-week period. Bandicoots (n = 16) and macropods (n = 9) were the most frequently observed victims. The mortality of wildlife was lower along the highway section with the crossing-structures (0.04 road-kills km–1) than it was along the highway section without structures (0.15 road-kills km–1). The lack of replication precludes any firm conclusion that the crossing-structures reduced road mortality but the high level of use of the crossing-structures by species that were common victims of road-kill suggests an influence.


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