scholarly journals Broad-scale movements of juvenile white sharks Carcharodon carcharias in eastern Australia from acoustic and satellite telemetry

2019 ◽  
Vol 619 ◽  
pp. 1-15 ◽  
Author(s):  
BD Bruce ◽  
D Harasti ◽  
K Lee ◽  
C Gallen ◽  
R Bradford
Keyword(s):  
Satellite Telemetry ◽  
Carcharodon Carcharias ◽  
Eastern Australia ◽  
Broad Scale

Broad-scale suppression of cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), associated with Bt cotton crops in Northern New South Wales, Australia

2016 ◽  
Vol 107 (2) ◽  
pp. 188-199 ◽  
Author(s):  
G.H. Baker ◽  
C.R. Tann
Keyword(s):  
Host Plant ◽  
Helicoverpa Armigera ◽  
Cotton Bollworm ◽  
Bt Cotton ◽  
Cotton Production ◽  
Bt Toxin ◽  
Pheromone Trapping ◽  
Eastern Australia ◽  
Helicoverpa Armígera ◽  
Broad Scale

AbstractThe cotton bollworm, Helicoverpa armigera, is a major pest of many agricultural crops in several countries, including Australia. Transgenic cotton, expressing a single Bt toxin, was first used in the 1990s to control H. armigera and other lepidopteran pests. Landscape scale or greater pest suppression has been reported in some countries using this technology. However, a long-term, broad-scale pheromone trapping program for H. armigera in a mixed cropping region in eastern Australia caught more moths during the deployment of single Bt toxin cotton (Ingard®) (1996–2004) than in previous years. This response can be attributed, at least in part, to (1) a precautionary cap (30% of total cotton grown, by area) being applied to Ingard® to restrict the development of Bt resistance in the pest, and (2) during the Ingard® era, cotton production greatly increased (as did that of another host plant, sorghum) and H. armigera (in particular the 3rd and older generations) responded in concert with this increase in host plant availability. However, with the replacement of Ingard® with Bollgard II® cotton (containing two different Bt toxins) in 2005, and recovery of the cotton industry from prevailing drought, H. armigera failed to track increased host-plant supply and moth numbers decreased. Greater toxicity of the two gene product, introduction of no cap on Bt cotton proportion, and an increase in natural enemy abundance are suggested as the most likely mechanisms responsible for the suppression observed.

Confirmation of little eagle (Hieraaetus morphnoides) migration by satellite telemetry

2018 ◽  
Vol 66 (4) ◽  
pp. 247 ◽  
Author(s):  
Renée Brawata ◽  
Stuart Rae ◽  
Bernd Gruber ◽  
Sam Reid ◽  
David Roberts
Keyword(s):  
Adult Male ◽  
Return Migration ◽  
Satellite Telemetry ◽  
Northern Territory ◽  
Australian Capital Territory ◽  
Satellite Transmitter ◽  
Eastern Australia ◽  
Breeding Migration ◽  
Open Woodland ◽  
The City

The post-breeding migration of an adult male little eagle (Hieraaetus morphnoides) was followed from south-eastern Australia to the Northern Territory using a GPS satellite transmitter. The bird bred in open woodland habitat on the edge of the city of Canberra, Australian Capital Territory (ACT), before it flew more than 3300km in 18 days, to winter in an area of eucalypt savannah in the Northern Territory. It remained there for 59 days, within a range of ~30km2, after which the last signal was transmitted. The bird was subsequently resighted back in its ACT territory at the end of winter, thus completing a return migration. This is the first confirmation of post-breeding migration for the species.

Broad-scale environmental gradients among estuarine benthic macrofaunal assemblages of south-eastern Australia: implications for monitoring estuaries

2004 ◽  
Vol 55 (1) ◽  
pp. 79 ◽  
Author(s):  
Alastair J. Hirst
Keyword(s):  
Community Structure ◽  
Spatial Scale ◽  
Environmental Gradient ◽  
Physical Parameters ◽  
South Eastern ◽  
Eastern Australia ◽  
Macrofaunal Community ◽  
Broad Spatial Scale ◽  
Broad Scale ◽  
South Eastern Australia

The importance of abiotic factors in explaining patterns of estuarine benthic macrofaunal community structure was examined on a broad spatial scale across south-eastern Australia. Macrofaunal communities were surveyed using an Ekman grab and a modified epibenthic sled (dredge) at each sampling site: data for 24 environmental variables were also collected. Twenty-eight estuaries were sampled on a single occasion during late summer at three stratified locations within each estuary (upper, mid and lower). Macrofaunal community composition was best explained by a common environmental gradient summarising variation in both salinity and longitude. Hence, although the distribution of macrofaunal taxa can be clearly linked to changes in salinity, the geographical position of the sites along an east–west axis, rather than a generalised down-stream gradient, appears to best explain the data. This association was primarily linked to broad-scale changes in estuarine morphology across the geographical range of this survey. A sediment-based environmental gradient among grab samples, but not dredge samples, reflected the largely infaunal nature of the grab samples. In general, the present survey did not support the classification of estuarine assemblages on the basis of a range of physical parameters but, instead, emphasised the continuity of estuarine benthic macrofaunal community structure on a broad spatial scale.

Inconspicuous, recovering, or northward shift: status and management of the white shark (Carcharodon carcharias) in Atlantic Canada

2020 ◽  
Vol 77 (10) ◽  
pp. 1666-1677
Author(s):  
G. Bastien ◽  
A. Barkley ◽  
J. Chappus ◽  
V. Heath ◽  
S. Popov ◽  
...  
Keyword(s):  
Action Plan ◽  
Satellite Telemetry ◽  
White Shark ◽  
Conservation Priorities ◽  
Atlantic Canada ◽  
Telemetry Data ◽  
Carcharodon Carcharias ◽  
Proactive Management ◽  
High Site ◽  
Research Incentives

Although white sharks (Carcharodon carcharias) have been considered rare in Atlantic Canada waters, recent sighting records indicate a potentially increasing presence. We combine historical to present sighting data with satellite telemetry tracks of large juvenile and adult white sharks tagged in US (n = 9) and Atlantic Canada waters (n = 17) to show seasonal white shark presence and distribution in Atlantic Canada, returns by individuals over multiple years, and high site fidelity to the region. Telemetry data indicate that white sharks are a more common and consistent occurrence in Canadian waters than previously thought, presenting two potential scenarios: (i) tagging technology is revealing white shark presence that was historically cryptic and (or) (ii) a northward range expansion of white sharks in the Northwest Atlantic, potentially due to climate change, population recovery, and (or) increasing pinniped prey. Given combined sighting and telemetry data indicate a current need for proactive management of white sharks in Atlantic Canada waters, we propose the basis for a management action plan, addressing conservation priorities, management goals, and research incentives while considering the potential for human–shark interactions.

Long-distance migrations by the hawksbill turtle, Eretmochelys imbricata, from north-eastern Australia

1998 ◽  
Vol 25 (1) ◽  
pp. 89 ◽  
Author(s):  
Jeffrey D. Miller ◽  
Kirstin A. Dobbs ◽  
Colin J. Limpus ◽  
Neil Mattocks ◽  
André M. Landry Jr
Keyword(s):  
Adult Female ◽  
Solomon Islands ◽  
Satellite Telemetry ◽  
Marine Turtle ◽  
Long Distance ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Eastern Australia ◽  
Nesting Beaches ◽  
Hawksbill Turtles

Tag recoveries from four adult female hawksbill turtles, Eretmochelys imbricata, tagged on the Great Barrier Reef, Australia, are reported. Hawksbill turtles on breeding migrations move between Australia and neighbouring countries including Vanuatu, Solomon Islands, Papua New Guinea and Indonesia. Migratory distances between foraging areas and nesting beaches ranged from 368 to 2425 km. A review of data from tag recoveries, genetic analysis and satellite telemetry indicates that adult female hawksbill turtles often exhibit migratory behaviour parallelling that of other marine turtle species. This study refutes the myth that hawksbill turtles remain resident at reefs associated with their nesting beaches.

scholarly journals Environmental conditions are poor predictors of immature white shark Carcharodon carcharias occurrences on coastal beaches of eastern Australia

2020 ◽  
Vol 653 ◽  
pp. 167-179
Author(s):  
JLY Spaet ◽  
A Manica ◽  
CP Brand ◽  
C Gallen ◽  
PA Butcher
Keyword(s):  
Environmental Conditions ◽  
Prey Availability ◽  
Statistical Significance ◽  
Time Of Day ◽  
White Shark ◽  
Additive Models ◽  
Large Sample Size ◽  
Lunar Phase ◽  
Carcharodon Carcharias ◽  
Eastern Australia

Understanding and predicting the distribution of organisms in heterogeneous environments is a fundamental ecological question and a requirement for sound management. To implement effective conservation strategies for white shark Carcharodon carcharias populations, it is imperative to define drivers of their movement and occurrence patterns and to protect critical habitats. Here, we acoustically tagged 444 immature white sharks and monitored their presence in relation to environmental factors over a 3 yr period (2016-2019) using an array of 21 iridium satellite-linked (VR4G) receivers spread along the coast of New South Wales, Australia. Results of generalized additive models showed that all tested predictors (month, time of day, water temperature, tidal height, swell height, lunar phase) had a significant effect on shark occurrence. However, collectively, these predictors only explained 1.8% of deviance, suggesting that statistical significance may be rooted in the large sample size rather than biological importance. On the other hand, receiver location, which captures geographic fidelity and local conditions not captured by the aforementioned environmental variables, explained a sizeable 17.3% of deviance. Sharks tracked in this study hence appear to be tolerant to episodic changes in environmental conditions, and movement patterns are likely related to currently undetermined, location-specific habitat characteristics or biological components, such as local currents, prey availability or competition. Importantly, we show that performance of VR4G receivers can be strongly affected by local environmental conditions, and provide an example of how a lack of range test controls can lead to misinterpretation and erroneous conclusions of acoustic detection data.

THE STRATIGRAPHY OF THE OFFSHORE GIPPSLAND BASIN

1971 ◽  
Vol 11 (1) ◽  
pp. 71 ◽  
Author(s):  
E. A. James ◽  
P. R. Evans
Keyword(s):  
Lower Cretaceous ◽  
Upper Cretaceous ◽  
Recent Sediment ◽  
Geological History ◽  
Lithostratigraphic Units ◽  
Eastern Australia ◽  
Latest Eocene ◽  
Gippsland Basin ◽  
Seismic Lines ◽  
Broad Scale

The Gippsland Basin in south-eastern Australia mainly underlies the continental shelf between eastern Victoria and Tasmania. It is filled with Lower Cretaceous-Recent sediment and has become a major source of hydrocarbons for the Australian market.Forty-two wildcat and stepout wells, additional development wells and over 7,000 miles of seismic lines provide a framework on which to build the region's geological history. The time-stratigraphy of the basin is derived from extensive use of spore-pollen assemblages in the mainly non-marine Cretaceous-Eocene and foraminifera in the marine Oligocene-Pliocene, largely complemented by seismic and to a lesser extent electric log correlations. Ten Cretaceous and five Paleocene-Eocene spore-pollen zones and fourteen Oligocene-Pliocene foraminiferal zonules are recognized. Only broad-scale lithostratigraphic units, initially recognized along the northern, onshore margin of the basin are traceable offshore. The Lower Cretaceous is represented by at least 10,000 feet of non-marine greywacke of the Strzelecki Group. The Upper Cretaceous-Eocene, with a cumulative thickness of 15,000 feet is termed the Latrobe Group and consists mainly of lacustrine and fluviatile elastics. Channels dissected the top of the Latrobe Group during the Eocene and were filled with sediments recognizable as distinct sequences within the group and termed the Flounder and Turrum Formations. A destructive marine phase during latest Eocene time left the glauconitic Gurnard Formation as the youngest member of the Group.Subsequent marine inundation of the basin resulted in deposition of up to 1,500 feet of calcareous mudstone referred to the Lakes Entrance Formation and up to 5,000 feet of marl, calcarenite and limestone of the Gippsland Limestone during the Oligocene and Miocene. Up to 1,000 feet of Pliocene- Recent calcarenite, micrite and marl complete the sedimentary sequence.

scholarly journals Forest Fragmentation: Wildlife and Management Implications

2000 ◽  
Vol 6 (3) ◽  
pp. 273
Author(s):  
Jarrad Cousin
Keyword(s):  
Pacific Northwest ◽  
Natural Ecosystems ◽  
Management Implications ◽  
Silvicultural Practices ◽  
South West ◽  
The Pacific ◽  
Eastern Australia ◽  
The World ◽  
Forested Ecosystems ◽  
Broad Scale

Fragmentation of natural ecosystems occurs throughout the world due to processes such as agriculture, forestry, mining and urbanization. Much of the wheatbelt regions of south-west and eastern Australia face major problems relating to the decline and extinction of resident flora and fauna. Much of the problem relates to the lack of knowledge of the processes and consequences of fragmentation. By the time problems have been addressed, damage to the ecosystems are often irreparable. In North America, much of the forested regions of the Pacific Northwest have also experienced broad-scale fragmentation of the natural forested ecosystems through extensive silvicultural practices.

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