Physicochemistry and Vegetation of Piccaninnie Ponds, a Coastal Aquifer-fed Pond in South-eastern South Australia

1990 ◽  
Vol 41 (2) ◽  
pp. 237 ◽  
Author(s):  
O Scholz
Keyword(s):  
Coastal Aquifer ◽  
Aquatic Vegetation ◽  
South Australia ◽  
Nutrient Content ◽  
Low Salinity ◽  
South Eastern ◽  
Loose Sediment ◽  
Chemical Stratification ◽  
Gradual Expansion

The aquatic vegetation and physicochemistry of Piccaninnie Ponds are described and recent annual losses of aquatic vegetation investigated. The aquifer-derived waters of the Ponds are characterized by their clarity, low nutrient content, low salinity, and lack of thermal and chemical stratification. In 1985, large areas of aquatic vegetation within the Ponds degraded and were lost. Subsequent faster regeneration of denuded areas by Ruppia polycarpa resulted in the displacement of Lepilaena cylindrocarpa. The annual uprooting of R. polycarpa, which has occurred since, results from Ruppia's comparatively poorer anchorage capacity in the loose sediment floc. Gradual expansion of L. cylindrocarpa into freshly uprooted regions restricts the regrowth of R. polycarpa and hence the area susceptible to denudation in the following year. It is expected that the displacement of R. polycarpa will continue until only small isolated stands remain, which will be prevented from uprooting by the root matrix of surrounding vegetation.

The Status of the School Shark Fishery in South-Eastern Australian Waters

1959 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
AM Olsen
Keyword(s):  
Maximum Yield ◽  
Reproductive Potential ◽  
South Australia ◽  
Slow Growth Rate ◽  
South Eastern ◽  
Pregnant Females ◽  
The Status ◽  
History Of ◽  
Annual Total ◽  
The Mean

The maximum yield of the school shark fishery in south-eastern Australian waters was 4.09 million lb in 1949. The catch has fluctuated since then about a declining trend to 3.18 million lb in 1956. In 1944, 7.3 hooks were required to catch a shark of mean weight 14.7 lb. In 1956 the number of hooks required was almost doubled: 13.6 hooks were needed to catch sharks of mean weight 13.7 lb; the catch per hook dropped from 2.01 to 0.99 lb. Whereas the catch per boat-month remained relatively stable at 4765 lb for 1944 and 4643 for 1956, the number of hooks used per boat-month increased from 2366 to 4668 hooks in 12 years. Throughout this period the mean weight of sharks in eastern Bass Strait remained fairly steady (11-13 lb) whereas there was a drop of 3 lb from a mean weight of 17-20 lb in the predominantly mature portion of the stock in western Bass Strait. Fishermen in South Australia have reported a comparable drop in the mean weight of sharks in their catches. During the period 1941-46 there was unrestricted inshore fishing of juveniles and pregnant females with a consequent severe drop in the inshore population. The subsequent decline in the annual total catch is believed to be due not only to a too intensive offshore fishery but also to the resultant reduced recruitment and depressed reproductive potential caused by the earlier destruction of juveniles and pregnant females. In the data presented in this paper there is evidence that the school shark fishery, which is operating on a single stock of sharks with a slow growth rate, a late sexual maturity, and a low fecundity, shows trends which are suggestive of depletion. Because similar trends in the soupfin shark fishery of California and in the dogfish fishery of British Columbia were followed by depletion, it has been inferred that regulations to protect the vulnerable phases of the life history of the school shark of Australia may be required. Measures for conservation are discussed.

Swamp wallaby (Wallabia bicolor) distribution has dramatically increased following sustained biological control of rabbits

2020 ◽  
Vol 42 (3) ◽  
pp. 321
Author(s):  
B. D. Cooke
Keyword(s):  
Biological Control ◽  
South Australia ◽  
Cumulative Effects ◽  
European Rabbit ◽  
High Rainfall ◽  
South Eastern ◽  
European Settlement ◽  
Western Victoria ◽  
Swamp Wallaby ◽  
Tiny Part

Swamp wallabies have dramatically extended their distribution through western Victoria and south-eastern South Australia over the last 40 years. Newspaper reports from 1875 onwards show that on European settlement, wallaby populations were confined to eastern Victoria, including the ranges around Melbourne, the Otway Ranges and Portland District of south-western Victoria, and a tiny part of south-eastern South Australia. Populations contracted further with intense hunting for the fur trade until the 1930s. In the late 1970s, however, wallabies began spreading into drier habitats than those initially recorded. Possible causes underlying this change in distribution are discussed; some seem unlikely but, because wallabies began spreading soon after the introduction of European rabbit fleas as vectors of myxomatosis, the cumulative effects of releases of biological agents to control rabbits appear important. A caution is given on assuming that thick vegetation in high-rainfall areas provides the only habitat suitable for swamp wallabies, but, most importantly, the study shows how native mammals may benefit if rabbit abundance is reduced.

Survival and biomass of exotic earthworms, Aporrectodea spp. (Lumbricidae), when introduced to pastures in south-eastern Australia

1999 ◽  
Vol 50 (7) ◽  
pp. 1233 ◽  
Author(s):  
G. H. Baker ◽  
P. J. Carter ◽  
V. J. Barrett
Keyword(s):  
South Australia ◽  
Clay Content ◽  
Total Biomass ◽  
Soil P ◽  
South Eastern ◽  
Inoculation Density ◽  
Eastern Australia ◽  
Exotic Earthworms ◽  
Soil Clay Content ◽  
South Eastern Australia

The earthworm fauna of pastures in south-eastern Australia is dominated by exotic lumbricid earthworms, in particular the endogeic species, Aporrectodea caliginosa and A. trapezoides. Anecic species such as A. longa are very rare. All 3 species were introduced within cages in 10 pastures on a range of soil types within the region. Five months later, A. longa had generally survived the best and A. trapezoides the worst. The survivals and weights of individual worms varied between sites for all 3 species. The survivals of A. caliginosa and A. longa, and to a lesser extent A. trapezoides, were positively correlated with soil clay content. The weights of A. caliginosa and A. longa, but not A. trapezoides, were positively correlated with soil P content. The survivals and weights of A. longa and A. trapezoides and the weights only of A. caliginosa decreased with increasing inoculation density, suggesting increased intraspecific competition for resources, particularly in the first two species. A. longa reduced the abundance and biomass of the exotic acanthodrilid earthworm, Microscolex dubius, at one site, and the total biomass of 3 native megascolecid species at another, when these latter species occurred as contaminants in A. longa cages. The addition of lime had no effect on the survivals and weights of A. caliginosa, A. longa, and A. trapezoides, although the soils were acid at the sites tested. The addition of sheep dung increased the survival and weights of some species at some sites. Mechanical disturbance of the soil within cages reduced the survivals of A. longa and A. trapezoides. A. longa was released without being caged at 25 sites within one pasture in South Australia. Four years later, it was recovered at all release points. A. longa has the potential to colonise pastures widely throughout the higher rainfall regions of south-eastern Australia.

Movement and mortality of Australian pelicans (Pelecanus conspicillatus) banded at inland and coastal breeding sites in South Australia

2015 ◽  
Vol 21 (4) ◽  
pp. 271 ◽  
Author(s):  
Gregory R. Johnston ◽  
Maxwell H. Waterman ◽  
Clare E. Manning
Keyword(s):  
South Australia ◽  
Population Declines ◽  
Long Distance ◽  
Breeding Sites ◽  
Continental Scale ◽  
South Eastern ◽  
Eastern Australia ◽  
Causes Of Mortality ◽  
Conservation Concern ◽  
South Eastern Australia

Globally, pelican populations have decreased, with three species being of conservation concern. Australian pelicans (Pelecanus conspicillatus) are not regarded as endangered, but have declined across south-eastern Australia. Information on their movements and causes of mortality are required to interpret the importance of these regional declines to the species’ global population. We explored patterns of movement and causes of mortality by analysing recoveries from 14 615 Australian pelicans banded over 37 years between 1969 and 2006. Data from 243 leg band recoveries showed that Australian pelicans move distances of up to 3206 km, and travel across the species’ entire geographic range, within a year of fledging. We found little evidence for the popular notion that these birds move en masse from the coast to inland areas in response to flooding rains. Maximum recorded age of a banded Australian pelican was 15 years. The banding data suggest that the regional pelican declines could reflect long-distance movements rather than an overall population response. However, a concentration of band returns from south-eastern Australia where the declines have been recorded, and the high incidence of human-induced deaths (16.4%) suggest otherwise. Accurate assessment of population trends in long-lived, long-distance nomads such as Australian pelicans requires assessment at a continental scale. Our results emphasise the importance of knowledge about fundamental aspects of a species’ biology for accurate interpretation of regional population declines.

Population ranges of Miniopterus schreibersii (Chiroptera) in south-eastern Australia

1969 ◽  
Vol 17 (4) ◽  
pp. 665 ◽  
Author(s):  
PD Dwyer
Keyword(s):  
New South ◽  
New South Wales ◽  
South Australia ◽  
South Eastern ◽  
Navigational Cues ◽  
South Wales ◽  
Eastern Australia ◽  
North Eastern ◽  
Western Victoria ◽  
South Eastern Australia

In south-eastern Australia banding of M. schreibersii has been concentrated in four areas: north-eastern New South Wales, south-eastern New South Wales, south-eastern Victoria, and south-western Victoria and south-eastern South Australia. The present paper analyses 2083 reported movements. Only 17 of these are from one of the four areas to another with the longest movement being 810 miles. Biologically and geographically separate populations of M. schreibersii are recognized in both north-eastern and south-eastern New South Wales. Each population has its basis in dependence upon a specific nursery site which is used annually by nearly all adult females in that population. Boundaries of population ranges in New South Wales are considered to be prominent features of physiography (i.e. divides). Bats move between population ranges less often than they move within population ranges. This cannot be explained solely in terms of the distances separating roosts. Available movement records from Victoria and South Australia are consistent with the pattern described for New South Wales. Two biologically recognizable populations (i.e, different birth periods) occur in south-western Victoria and south-eastern South Australia but these may have overlapping ranges. Only one nursery colony of M. schreibersii is known from south-eastern Victoria. On present evidence it remains possible that the apparent integrity of the population associated with this nursery is merely a consequence of distance from other areas of banding activity. Detailed analyses of movements in bats may provide direct evidence as to the kinds of cues by which a given species navigates. Thus the physiographic basis described for population ranges in New South Wales is consistent with the view that M. schreibersii may orientate to waterways or divides or both. The probability that there are area differences in the subtlety or nature of navigational cues is implied by the different physiographic circumstances of south-western Victoria and south-eastern South Australia. It is suggested that knowledge of population range boundaries may aid planning of meaningful homing experiments.

A Parapatric Boundary between Ranidella signifera and R. riparia (Anura: Leptodactylidae) in South Australia

1982 ◽  
Vol 30 (1) ◽  
pp. 49 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull
Keyword(s):  
Competitive Advantage ◽  
Close Association ◽  
South Australia ◽  
Wide Distribution ◽  
Habitat Types ◽  
South Eastern ◽  
The North ◽  
Flinders Ranges ◽  
Eastern Australia ◽  
Overlap Area

Ranidella signifera has a wide distribution in south-eastern Australia; R. riparia is endemic to the Flin- ders Ranges in South Australia. The ranges of the two species are largely allopatric, but they contact and overlap in a zone about 10 km wide, in the southern Flinders Ranges. The nature of the creeks changes across this zone. Immediately to the south and east, where only R. signifera is found, the creeks are slow-flowing and heavily vegetated, with mud or sand substrates. To the north and west the creeks are swift-flowing, and have rocky substrates and little vegetation; only R. riparia is found in these. In the sympatric overlap zone creeks are heterogeneous, with both habitat types represented. The close association between species and creek habitat is lost in populations not immediately adjacent to the overlap zone. This implies that each species can survive in both creek habitats but that R. riparia has a competitive advantage in swift, rocky creeks and R, signifera has an advantage in slow, vegetated creeks. This prevents either species from expanding its distribution beyond the narrow overlap area.

Larval distribution and abundance of blue and spotted warehous (Seriolella brama and S. punctata: Centrolophidae) in south-eastern Australia

2001 ◽  
Vol 52 (4) ◽  
pp. 631 ◽  
Author(s):  
B. D. Bruce ◽  
F. J. Neira ◽  
R. W. Bradford
Keyword(s):  
Life Histories ◽  
New South ◽  
South Australia ◽  
South Eastern ◽  
Larval Distribution ◽  
South Wales ◽  
Spawning Areas ◽  
Eastern Australia ◽  
Commercially Important ◽  
South Eastern Australia

The early life histories of the commercially important blue and spotted warehous (Seriolella brama and S. punctata) were examined on the basis of archived ichthyoplankton samples collected over broad areas of southern Australia. Larvae of both species were widely distributed during winter and spring within shelf and slope waters. Larvae of S. brama were recorded from Kangaroo Island, South Australia (SA), to southern New South Wales (NSW). Seriolella punctata larvae were recorded from western Tasmania to southern NSW. Back-calculated spawning dates, based on otolith microstructure, indicated that spawning predominantly occurs during late July and August but that the timing of spawning varies between regions. The abundances of small larvae (<5. 0 mm body length) were highest for both species off western Tasmania and southern NSW. No small S. brama larvae were recorded between southern Tasmania and southern NSW, whereas low but consistent numbers of small S. punctata larvae were found between these regions. The data suggest that there are separate spawning areas for S. brama in western and eastern regions of Australia’s South East Fishery. The pattern for S. punctata is less clear, but suggests a more continuous link among populations in south-eastern Australia.

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