An estimate of Bass Strait water Movement in the Western Tasman Sea during the Australian Coastal Experiment

1989 ◽  
Vol 40 (5) ◽  
pp. 465 ◽  
Author(s):  
M Tomczak ◽  
E Tanner

The presence and movement of Bass Strait Water along the continental slope of south-eastern Australia during the Australian Coastal Experiment (ACE) is estimated by evaluating the amount of salt and heat imported from Bass Strait for the five standard hydrographic ACE sections. South of Jervis Bay (35°S), the amounts decrease from September 1983 to February 1984 by a factor of two. North of Jervis Bay, the amounts depend strongly on the position of the East Australian Current and its eddies. It appears that during periods of low eddy activity Bass Strait Water can be carried northward well past Newcastle (33�S).

1997 ◽  
Vol 48 (6) ◽  
pp. 473 ◽  
Author(s):  
Mark T. Gibbs ◽  
Patrick Marchesiello ◽  
Jason H. Middleton

A numerical simulation of the East Australian Current (EAC) has been used to investigate the nutrification of shelf waters at Jervis Bay, south-eastern Australia, prior to the massive coccolithophorid bloom that was first observed on 16 December 1992. The simulation suggests that a small cold-core eddy developed between the continental slope at Jervis Bay and the EAC jet further offshore during 7 and 14 December 1992. This unstable cold-core eddy is likely to have uplifted cold, nutrient-rich water onto the Jervis Bay shelf, and this upwelling, in combination with upwelling-favourable winds, probably transported nutrients from the deep ocean to the entrance of the bay.


1991 ◽  
Vol 31 (1) ◽  
pp. 131 ◽  
Author(s):  
T. A. Dumitru ◽  
K. C. Hill ◽  
D. A. Coyle ◽  
I. R. Duddy ◽  
D. A. Foster ◽  
...  

Over the last five to ten years, apatite fission track analysis has developed into a sophisticated technique for studying the low-temperature thermal history of rocks. It has particular utility in oil exploration because its temperature range of sensitivity, about 20° to 125°C, overlaps the oil generation window. Whereas older fission track thermal history approaches relied solely on the sample fission track age, the new interpretive approaches use sample age, single grain age and track length data. They also emphasise the analysis of systematic variations in data patterns in sequences of samples, such as samples from various depths in a well. Laboratory study of the thermal annealing of fission tracks and compilation of fission track data from geological case studies has greatly improved our understanding of apatite fission track systematics, allowing considerably more detailed interpretations of thermal histories.Application of apatite fission track analysis to the rifted continental margins of south-eastern Australia shows that rifting and separation of Australia from Antarctica and the Lord Howe Rise were accompanied by at least 1.5-3 km of uplift and erosion along the Tasman Sea and Bass Strait coasts. Uplift and erosion were much less 100 km or so inland. This shows that the uplift of the south-eastern Australian margins was caused by the continental rifting process, the same process that initiated major subsidence in the sedimentary basins in Bass Strait. The consistent fission track data patterns around south-eastern Australia suggest a generally similar tectonic setting for the Tasman Sea and Bass Strait parts of the margin. Lister et al. (in press) propose that the Tasman part of the margin is an upper plate type of margin that formed above a west-dipping detachment zone. The fission track data suggest that the Bass Strait part of the margin may also be of upper plate type.


1997 ◽  
Vol 48 (2) ◽  
pp. 91 ◽  
Author(s):  
J. M. Lyle ◽  
D. C. Smith

The distribution, abundance, size structure, reproductive biology and diet of warty oreo, Allocyttus verrucosus (Gilchrist), and spiky oreo, Neocyttus rhomboidalis (Gilchrist), from the continental slope region (400-1200 m depth) of south-eastern Australia are described. The depth distributions of the two species overlap, with spiky oreo being more abundant in intermediate depths (600-800 m) and warty oreo abundance peaking at greater depths (900-1200 m). There was evidence of size structuring with depth. Warty oreo juveniles and subadults were comparatively more abundant in depths of less than 1000 m and adults dominated at greater depths. In spiky oreo, juveniles were largely restricted to the depth range of 700-900 m. Size at 50% maturity in females was 28 and 35 cm for warty and spiky oreos, respectively. Males mature at slightly smaller sizes. Spawning occurs in May–June for warty oreo and between August and October for spiky oreo. Just prior to spawning in warty oreo the sexes appear to segregate by depth, with females becoming progressively more dominant with depth. Both species are benthopelagic feeders, consuming a range of prey items including crustaceans, fish and squid. Salps were also an important component of the diet of spiky oreo.


1969 ◽  
Vol 20 (2) ◽  
pp. 163 ◽  
Author(s):  
K Walker

Halicarcinus lacustris is a small crab inhabiting inland waters in south-eastern Australia, New Zealand, and Lord Howe and Norfolk Islands. The Victorian distribution was investigated with reference to salinity. In the field the species occurs over a salinity range of 0.1-9.6‰ (although scarce in fresh waters), despite a tolerance of 0.0-36.3‰ shown by adults in the laboratory. This restricted distribution is attributed to physiological and ecological factors. Ecological notes are included on microhabitat, associated species, food, and the breeding cycle. Consideration is given also to the origins and overall distribution of the species. It is suggested that H. Lacustris rafted across the Tasman Sea, after having evolved in south-eastern Australia.


2020 ◽  
Author(s):  
Daniel J. Ohlsen ◽  
Lara D. Shepherd ◽  
Leon R. Perrie ◽  
Patrick J. Brownsey ◽  
Michael J. Bayly

Asplenium flabellifolium Cav. is a cytologically variable Australian and New Zealand fern. Here, we sequence chloroplast trnL-trnF and rps4-trnS from samples throughout its range to provide the first phylogeographic investigation of a fern common in both countries. Twenty-three haplotypes were detected, which formed six haplogroups in a network. Australian specimens were placed in all haplogroups. The placement of New Zealand haplotypes in five of the haplogroups suggests that this species has dispersed across the Tasman Sea at least five times. Sexually reproducing plants of lower ploidy, detected only in south-eastern Australia, contained haplotypes from the two haplogroups that are successive sisters to the remaining diversity in the phylogeny. This likely suggests that A. flabellifolium was originally a sexually reproducing species in south-eastern Australia and spread to the rest of its distribution where apomictic plants dominate. More than one haplogroup was detected in several areas across its distribution, suggesting that these areas were colonised several times. Other areas harboured several haplotypes from a single haplogroup or haplogroups not recovered elsewhere, indicating possible long-term persistence in these areas. Haplotypes and morphological features were not found to be exclusive to either breeding system or ploidy and no taxonomic revision is proposed.


1986 ◽  
Vol 37 (5) ◽  
pp. 621 ◽  
Author(s):  
CM Bulman ◽  
SJM Blaber

The diet and feeding ecology of the demersal merlucciid M. novaezelandiae from three areas of the upper continental slope (420-550 m) of south-eastern Australia are described. The food consists almost entirely of mesopelagic fauna. The major prey are myctophid fish Lampanyctodes hectoris, other fishes, natant decapods, euphausiids and squid. Energy values of major prey items were determined by bomb calorimetry. Although euphausiids occur frequently in the diet, fish make up 90% of the energy intake. There is little regional variation. M. novaezelandiae undertakes diel vertical migrations that are similar to those of its prey, bringing it within 50 m of the surface at night. There is a seasonal trend towards cannibalism by adults on juveniles.


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