Creation year

2008

33 record(s)
 
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  • Interactions between native and introduced species can help to elucidate the impact of exotic species on the broader community. This work examines utilisation of an introduced gastropod, the New Zealand screwshell (Maoricolpus roseus) by native hermit crabs in eastern Tasmania. Samples of screwshells were collected from Bass Strait, Maria Island, Pirates Bay and Dennes Point using a modified scallop dredge or collected by divers. Site location, date, depth, dredge opening size were recorded, and random sub-samples of shells were measured for length and width, and spire damage was scored. Hermit crabs, if present, were identified to species, sexed and measured.

  • Samples of Octopus maorum and O. pallidus have been collected from the Eaglehawk fishery and as bycatch from southern rock lobster fishery to determine population structure and spatial and temporal trends. Tag recapture study of O. maorum and O. pallidus in Taroona reserve using PIT tags and movement study using acoustic tracking at Taroona reserve and Eaglehawk neck examine the temporal and spatial scales of movement and habitat use. Octopus tracked using VR2's (presence/absence data) and VRAP (triangulated positional data) at both sites.

  • Interactions between native and introduced species can help to elucidate the impact of exotic species on the broader community. This work examines utilisation of an introduced gastropod, the New Zealand screwshell (Maoricolpus roseus) by native hermit crabs in eastern Tasmania.

  • Sampling of commercial mid-water trawl catches for small pelagics from waters adjacent to Tasmania have yielded an extensive biological dataset in space and time. As a minimum, size composition information is available from most commerical shots undertaken between 2002 and 2006, referenced with operational information (location, depth and catch weight). Subsamples of the key small pelagics, redbait, jack mackerel and blue mackerel, were examined for size, sex, gonad weight and stage and otoliths have been retained for age determination. Further data has been collected since the initial investigation.

  • The impact of the introduction of the New Zealand screwshell (Maoricolpus roseus) on scallop distribution and behaviour in the D'Entrecasteaux Channel, SE Tasmania was investigated. The impact of both live and dead and empty M. roseus shells on the distribution of two sympatric scallop species, queen scallop (Equichlamys bifrons) and doughboy scallop (Chlamys asperrimus) was quantified at large spatial scales. Also quantified was the impact of M. roseus on the distribution and behaviour of the commercial scallop (Pecten fumatus), at both large and small spatial scales.

  • Interactions between native and introduced species can help to elucidate the impact of exotic species on the broader community. This work examines utilisation of an introduced gastropod, the New Zealand screwshell (Maoricolpus roseus) by native hermit crabs in eastern Tasmania. Variation in shell occupancy by hermit crabs was examined across different depths (10, 20, 30 and 40m) within a single site (Dennes Point, SE Tasmania). Sediment cores were taken from 10 and 20 m to compare sediment size structure. A sediment preference trial using the hermit crab Paguristes tuberculatus was also carried out (using sediment from 10m and 20m) to try and determine the low level of hermit crab occupancy at 20m (compared with that at 10m).

  • The data was collected from 2 years of field sampling from the commerical octopus (Octopus pallidus) fishery in NW Tasmania in Bass Strait. The data consists of morphological, reproductive and ageing information.

  • This study used crosses of wild-caught dumpling squid (Euprymna tasmanica) males to multiple females with known behavioural types to evaluate patterns of additive and residual variance in behavioural traits from offspring under two contexts - a threat and a foraging test. Genetic contributions to behavioural expression were context-dependent. Threat context behaviour had significant heritability, while foraging context behaviour had lesser additive and greater residual components. Female trait variation was not correlated with fecundity. Female foraging boldness (which co-varied with size) explained some variation in brood hatching success. Positive assortion of mate pairs according to shy-bold phenotype determined fertilization success.

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    Black Jew fish in the Northern Territory and Banded Morwong and Bastard Trumpeter in Tasmania have been tagged with acoustic tags and tracked using VR2's (presence/absence data) and VRAP (triangulated positional data) (Tas fish only).

  • Sea urchin tagged using tetracycline display visible marks in jaw elements and test plates that can be used to determine growth and subsequently an individuals age. Natural growth lines in the same structures can be used to determine age if natural lines are deposited at a consistent rates independent of age. Sea urchins were tagged using tetracycline and age determined from both fitted growth models and the number of bands deposited. Rates of natural line deposition were also quantified.