41 resultados para Narragansett Bay

em Deakin Research Online - Australia


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This collection of resources provides classroom examples and case studies, offers a platform of ideas for teachers to investigate new ways of building the literacy development of their students.

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The isolated lower molar series of a dasyurid from early Pleistocene sediments at Nelson Bay, near Portland, is referred herein to Sarcophilus laniarius harrisii (Boitard, 1842). Dental measurements and morphological comparisons taken from this tooth series compare closely with those of the extant subspecies. The genus Sarcophilus is known from the early Pleistocene by the species S. moornaensis Crabb 1982. Fossil material assigned to S. laniarius harrisii is now also known from Early Pleistocene sediments. The new specimens from Nelson Bay extend the origin of S. laniarius harrisii to the early Pleistocene.

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The White-faced Storm Petrel (Pelagodroma marina) is restricted to three breeding colonies within Victoria: Mud Islands and South Channel Fort in Port Phillip Bay, and Tullaberga Island off Mallacoota. Numbers of these storm petrels breeding on Mud Islands have declined considerably since early last century. White-faced Storm Petrels were recorded on Mud Islands from early September 2002 until mid-March 2003 when the last chicks fledged. Eggs were laid from late October to early December, with chicks hatching in the later half of December. The mean incubation period was 51.7 days (± 3.2 days (s.d.), range = 38–53, n = 13), and may have been extended by periods of egg neglect. The mean nestling period was 54.8 days (± 4.4 days (s.d.), range 50–70, n = 21). Chick growth is described. Hatching success was 54% and fledging success was 77.8%, with overall breeding success being 42%. Burrow densities were found to be influenced by plant species, vegetation height and soil moisture. The position of the burrow within the colony was shown to influence breeding success, with those nearer the edge of the storm petrel colony, closer to the marsh, and further from a colony of Australian White (Threskiornis molucca) and Straw-necked (T. spinicollis) Ibis recording higher success.

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The genetic composition of greenlip abalone (Haliotis laevigata) from Point Cook in Port Phillip Bay was examined prior to the aggregation of individuals from this site for ranching. The very thinly distributed natural population at Point Cook was believed to be of low genetic diversity, because the animals all originated from a single spawning event 5 y previously. Animals from Point Cook were compared with other H. laevigata from two sampling sites within Port Phillip Bay, and two sites outside the Bay in Bass Strait, to examine their genetic diversity and origin. Variation was assessed at five microsatellite loci. Deviations from Hardy-Weinberg equilibrium (HWE) were observed at some loci in various populations, but the Point Cook population was in HWE at all five loci. Mean heterozygosity and number of alleles was similar in all populations. Hierarchical analysis of molecular variance indicated significant genetic variation among populations, but did not differentiate Port Phillip Bay from Bass Strait populations. Pairwise comparisons of multilocus FSTand RST indicated significant genetic differences between Point Cook and some populations, as well as between other populations, but no consistent spatial pattern of differentiation was observed. There was no significant correlation between genetic and geographic distance. The level of genetic variation observed in the Point Cook individuals was similar to that in individuals from the other four sites, and sufficient to support a ranching program. However, this variation should be monitored to maximize genetic potential, and avoid commercially undesirable effects of inbreeding. Implications of this study in relation to the management of a ranching population in Port Phillip Bay are discussed.

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The littoral environments present in Shoal Bay, Northern Territory (Australia) show a high diversity of ostracods cytheráceos (51 genera and 97 species). Probably this diversity is due to three factors: (1) marine environments warm and well oxygenated leading to a high level of biological productivity, (2) shallow marine environments favorable for the accumulation of material conchífero post mortem, and (3) a location central in the way of dispersal on the continental shelf between the regions of the Pacific and Southeast Asia. A particular feature of this fauna Cytherscea is that some genres, such as Alocopocythere, can be traced back to the Cretaceous when it first appeared in the shallow waters of the Tethys. In this overlay component of the ancient ostracods are the dominant fauna in partnerships of the modern Indo / Pacific, such as gender Keiji. While the Cytheracea ostracods are the dominant groups, especially the Cypridacea marine Bairdiacea and Plstycopina, are well represented and are quite different (fide Whatley et al., 1995, 1996). We describe here a new genre, Paraxestoleberis, and 15 new species: Dentibyíhere multituberosa, Dampiercythere papillolineata, Neocyíheromorpha papilloporosa, Loxoconcha catasíeros, Semicyrherura gamma, Callistocyíhere cookei, Loxocorniculum koolpionyahensis, Keúia interim, K. profundosculpia, K. parademissa, Quasibradleya leepoiníensis, Actinocyíhereis gippsi, Henryhowella sinespinosa, Poníicocyíhereis spatulospinosa and Paraxestoleberis posteroacuminata. Due to the limited material obtained, 16 species are kept in open nomenclature: Bythoceratina sp. Corallicyíhere sp. Venericythere sp. Tanella sp. Loxocorniculum sp. 1 L. sp. 2, Gambiella sp. Javanella sp. Paradoxostoma sp. Neomonoceratina sp., Bradley (sl) sp. Echinocytbereis (sl) sp. Plaíycyíhereis? sp. Alocopocyíhere sp. Xestoleberis sp. and Paraxestoleberis sp. The remaining 66 species have been described previously in other areas.

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The influence of age on reproductive success and diet was examined in ‘old’ (experienced; 12 years and older) and ‘young’ (5–8 years of age) Australasian gannets (Morus serrator) breeding at Pope’s Eye, Port Phillip Bay, Victoria during the 2002–2003 breeding period. Although food availability, as indicated by commercial fish catches, throughout this breeding period was low, there were no significant differences in breeding success or chick growth between groups. Nevertheless, old birds tended to have higher reproductive success, replacing more lost eggs and fledging chicks of a greater mass. However, old birds also laid more eggs that failed to hatch. Five fish species, including jack mackerel (Trachurus declivis), barracouta (Thyrsites atun), redbait (Emmelichthys nitidus), anchovy (Engraulis australis) and red mullet (Upeneichthys vlamingii), were important in the gannet diet during this breeding period. There were no significant differences in dietary parameters, including range of species and size of prey, between old and young gannets, nor were there any differences between those of the chicks and their parents, suggesting that adults do not forage selectively for their chicks. This study showed that even during a period of presumed low food availability, when experienced (older) birds might be expected to have enhanced success, the differences between these and less experienced (younger) birds may not be apparent.

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To optimise lifetime reproductive success, individuals must balance current reproductive effort against future reproductive prospects. In birds, incubation and chick-rearing must involve costs, and manipulation of the length of incubation offers an insight into some costs affecting adults. An experiment was conducted at a colony of Australasian Gannets in Port Phillip Bay, Victoria, in which length of incubation was manipulated so that some adults experienced short (10–20 days duration), long (70–80 days) or normal (~45 days) incubation periods. Adults with a manipulated incubation period did not show significant differences in weight change (taken here to reflect cost) during incubation or chick-rearing compared with controls. Manipulation of length of incubation did not significantly affect the hatching success or the growth rate of chicks involved and is not, therefore considered to impose an increased reproductive cost. This suggests that the Australasian Gannet has the capacity to maintain body condition and successfully rear young despite modified duration of incubation.

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Government environment protection policies for waterways have traditionally relied on water quality indicators and their objectives. In this paper we describe the development of biological objectives based on invertebrate indicators for inclusion in a government policy for the catchment of Western Port Bay, Victoria. The first step of defining segments (areas with streams in which the same objectives are applied) was problematic, requiring two different approaches, as follows. Site groups initially based on invertebrate community composition derived using multivariate techniques (ordination and classification) proved to be unsuitable for policy segments. Segment boundaries were subsequently defined using topographical (e.g. boundary of foothills and lowland plains), climate (e.g. rainfall) and land-use (e.g. urban) features. We used information and data from reference sites inside as well outside the catchment to derive specific biological objectives based on aquatic invertebrates for these segments. Objectives were specified for the following four indicators – number of invertebrate families, the SIGNAL index, the AUSRIVAS predictive model and the number of key families.