962 resultados para Restraint of trade -- Australia


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The marron, Cherax tenuimanus (Smith), is one of the most easily recognisable members of the freshwater crayfish genus Cherax. Since its description in 1912, the taxonomy of the species has not been in dispute, but recent genetic studies have demonstrated that the species is not homogenous and consists of two genetically distinct forms. One of these forms is widespread and exploited via aquaculture and the other is restricted to a single river system, the Margaret River. This paper presents allozyme data, collected over a 19-year period, which documents the introduction of the widespread form into the Margaret River and the subsequent reproductive interactions between the two forms. These data indicate minimal interbreeding between the two forms of marron and so justify their recognition as distinct species. As the original description of the marron was based on specimens collected from the Margaret River, the form native to this river retains the name C. tenuimanus and a new species, Cherax cainii Austin is described for the common, widespread form of marron. An additional outcome of this study is that C. tenuimanus has been rapidly displaced by the introduced C. cainii within the Margaret River. Consequently, urgent conservation measures are required to protect C. tenuimanus and prevent its possible extinction.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Caging and a mark–recapture design were used to estimate the growth rate of the brittle, infaunal bivalve Soletellina alba in the Hopkins River estuary. The growth of both caged and uncaged individuals was monitored at three sites near the mouth of the estuary over 180 days. Growth rates did not differ for caged and uncaged bivalves, or for bivalves subject to different amounts of handling, or between sites. Growth did differ between consecutive time intervals, which was attributable to negligible growth occurring during the colder months of autumn/winter. Comparisons of the condition (as indicated by total mass for length3) of S. alba were inconsistent between sites for caged and uncaged bivalves and for those subject to different amounts of handling. Soletellina alba is a rapidly growing bivalve with mean growth rates for the three time intervals being 0.04±0.002 mm day−1 in summer, 0.02±0.001 mm day−1 in autumn and 0.03±0.001 mm day−1 from summer to winter. Using existing literature, it was shown that a significant relationship exists between maximum shell length and onset of sexual maturity in bivalve molluscs. This relationship predicts that S. alba should reach the onset of sexual maturity at 15.8 mm length. Therefore, it appears that it may be possible for juvenile S. alba (<1 mm) to grow, reach sexual maturity and reproduce in between annual mass-mortality events caused by winter flooding.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study on the Mio–Pliocene ostracod successions of southeast Australia outlines several faunal events indicative of climate warming and/or increased rainfall events. Ostracod faunas associated with a late Late Miocene sea level rise event suggest that the climate of this time in southeast Australia was similar to, or slightly warmer than that of present day southeast Australia. However, it was probably wetter and significantly warmer than immediately preceding (mid Late Miocene) palaeoclimatic conditions within the region. Evidence for a change to wetter and warmer conditions during the late Late Miocene is seen in the appearance of various extant euryhaline and semi-thermophilic ostracod species in coastal ostracod faunas. The appearance of euryhaline species, which are mostly absent from older shallow marine Cenozoic strata of the Bass Strait hinterland, suggests a major influx of fresh water into coastal marine settings, which contributed to the initial phase of development of the southeast Australian late Neogene barrier coastline and associated marginal marine palaeoenvironments.

During the time interval latest Miocene to earliest Pliocene, and during the early Late Pliocene, two subsequent global sea level rise events are also preserved in the southeast Australian coastal plain. Many of the species present in ostracod faunas associated with these two events are the same as in older local late Late Miocene faunas. In earliest (?) Pliocene faunas, there is minor evidence for the reappearance of semi-thermophilic ostracods. Faunas of early Late Pliocene age often exhibit a conspicuous faunal dominance by, or large abundance of euryhaline species, indicating the particularly strong influence of fresh water influxes into coastal marine palaeoenvironments. This may reflect the presence of especially wet local temperate palaeoclimatic conditions during a time of equable global climates.

Succeeding estuarine, lagoonal and coastal embayment ostracod faunas of late Late Pliocene age are associated with marginal marine sediments that are interbedded with coastal dune aeolianites. This suggests an overall seaward retreat of marginal marine environments that was initiated by a major global sea level fall linked to the onset of cooler Late Pliocene and Quaternary global climates.


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ground-foraging birds of temperate woodlands of southern Australia are prominent among bird species considered to be susceptible to population decline. We examined the foraging ecology, including foraging substrates, actions and heights, of 13 ground-foraging species at four woodland sites in northern Victoria. Nine species are regarded as declining in southern Australia and four are considered common. Ten foraging substrates were identified, of which leaf-litter (54% of observations) and bare ground (17%) were most frequently used. In all woodland sites, litter was used more frequently than expected from its proportional cover. Bare ground was frequently used as a substrate by individual species, and fallen timber and grass were important for some species. Most species were generalists in their use of substrates. Six foraging actions were observed, of which gleaning and pouncing were most frequently recorded. All species foraged close to the ground and four foraged almost entirely at ground level. For pouncing birds, dead branches and fallen timber were the most important launch substrates from which pouncing actions were initiated. Eight of the 13 species differed in some aspect of their foraging ecology between woodland sites, especially in relation to the use of substrates (seven species). Fewer species (four) displayed differences in foraging ecology between seasons, with the greatest seasonal variation being in use of foraging substrates (three species). Overall, no significant differences were evident in the foraging ecologies of common and declining species. Species in both groups encompassed a wide range of foraging behaviours. Owing to this range in foraging ecology, the conservation of diverse assemblages of ground-foraging birds requires the maintenance of heterogeneous ground layers and careful management of disturbance processes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In an earlier paper we adopted a BEKK-GARCH framework and employed a systematic approach to examine structural breaks in the HSIF and HSI volatility. Switching dummy variables were included and tested in the variance equations to check for any structural changes in the autoregressive volatility structure due to the events that have taken place in the Hong Kong market. A Bi-variate GARCH model with 3 switching points was found to be superior as it captured the potential structural changes in return volatilities. Abolishment of the uptick rule, increase of initial margins for the HSIF and electronic trading of HSIF were found to have significant impact on the volatility structure of HSIF and HSI. In this paper we include measures of daily trading volume from both markets in the estimation. Likelihood ratio tests indicate the switching dummy variables become insignificant and the GARCH effects diminish but remain significant.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Lichen floristics and distribution were examined in cool temperate rainforests of Victoria, Australia. Forty sites were sampled, ten from each of the Otways, Yarra Ranges, Baw Baw, and Errinundra regions. A total of 165 lichen species were recorded, representing 38 fam- ilies. Seventeen species are new for Victoria. Non-metric Multidimensional Scaling showed three lichen groups that corresponded with the rainforest types in which they occurred. A sub-group of lichen species were considered widespread and represented the core of Victoria's rainforest lichen flora.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The marketing approach used by Volvo to debunk the stigma of "Bloody Volvo Driver" in the Australian marketplace appears to be a rare approach and could be perceived to some extent as being 'masochistic'. A masochistic marketing approach, as coined by the authors of this paper, is a high-risk venture. It is a challenging and a demanding initiative because it plays on the humiliation of the corporate image itself. The core idea of the masochistic marketing approach violates, or at least appears to oppose, the fundaments of marketing. The underlying idea is to tum a stigmatised image in the marketplace into something useful and valuable in forthcoming marketing and business activities, however, in the process that corporate image may deteriorate even further.