Creation year

2011

79 record(s)
 
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From 1 - 10 / 79
  • Webcam established at North Bay, Tasmania, early 2010 as a deterrent for poaching translocated lobsters. Webcam is sited on the southern end of the site facing north. Pictures are taken every 15 minutes and transmitted to a server where they can be accessed remotely by users. As at Novenber 2011, pictures are still being taken and archived.

  • Linear video transects (40m total length; 20m into barrens and 20m into kelp from original fixed marker on the benthos) were used to assess changes in kelp growth in several points along the kelp - urchin barren interface in north-east Tasmania (St. Helens Island, Sloop Rock and Elephant Rock research areas). The video transects were deployed in the same position, and assessed at different points of time. The video was analysed in the laboratory to assess percentage of kelp and barren cover, as well as the kind of substratum, kelp species identifiable and number of sea urchins (Centrostephanus rodgerii and Heliocidaris erythrogramma) and other benthic organisms when present (rock lobster and abalone).

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    Belt transect surveys (50m) were used to monitor the benthic community structure through time at experimental (lobster additions/ research reserve sites or abalone diver urchin culls) and control sites in eastern Tasmania. Measures of percentage cover of key algal guilds, percentage of reef grazed by sea urchins, number of sea urchins (Centrostephanus rodgersii, Heliocidaris erythrogramma), Abalone (Haliotis Rubra), Rock lobsters (Jasus edwardsii) and type of substratum were recorded.

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    Zooplankton samples were collected at inshore coastal waters of south eastern Tasmania, between the years 1971 and 1972. Three stations were selected to cover the D'Entrecasteaux Channel, mouth of the Derwent River and the Storm Bay areas. Surface, midwater and bottom zooplankton samples were collected monthly for a period of twelve months during the day as well as night time, using horizontal tows. Data for temperature and salinity were also obtained from the stations.

  • A 12-month program was developed and implemented in order to obtain baseline information on water quality (salinity, water temperature, dissolved oxygen, turbidity, pH, dissolved nutrients, silica), ecological condition as shown by Chlorophyll a, benthic macroinvertebrates, pathogens, and habitat extent determined from habitat mapping. Five key estuaries and coastal waters were assessed in the Southern NRM Region of Tasmania. The data represented by this record was collected in Moulting Lagoon/Great Swanport.

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    These data were collected on the RV L'Astrolabe (platform code: FHZI) from 19/02/2003 to 24/02/2003 on a trip from Hobart to Dumont d'Urville. Maximum photochemical efficiency of photosystem II (PSII), also called maximum quantum yield of PSII (Fv/Fm), has become one of the most widely utilized fluorescence parameters in phytoplankton research. It represents the potential photochemical efficiency, which is the probability that the light energy captured by the photosynthetic apparatus is being utilized as photochemistry. Fv/Fm has been shown to have an instant response to variations in physical and chemical properties and is interpreted as a diagnostic of the overall health or competence of phytoplankton. Together with the absorption cross section area of PSII and chlorophyll concentration, it can be used to measure primary production (Cheah et al. 2011, Deep Sea Research). Seawater from 3 m depth was supplied continuously from the ship’s clean seawater line. FRR fluorescence yields were measured continuously at 1 minute intervals in dark-adapted state (! 15 minutes dark-adaptation) using a flash sequence consisting of a series of 100 subsaturation flashlets (1.1 μs flash duration and 2.8 μs interflash period) and a series of 20 relaxation flashlets (1.1 μs flash duration and 51.6 μs interflash period).

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    Dredge rocks were recovered on scientific voyage SS2011_06 on the MNF RV Southern Surveyor, from the Perth Abyssal Plain, offshore Western Australia. Continental rocks (gneiss, granite, sandstone) were dredged from both the Batavia Knoll and the Gulden Draak Ridge (dredge sites 1, 2, and 3). A small amount of high weathered basalt was recovered from the Gulden Draak Ridge (dredge site 4). Three successful dredges were undertaken along the Dirck Hartog Ridge recovering predominantly gabbro (dredge 5) and basalts (dredge sites 6 and 7).

  • This study considered a range of water-column and sediment (benthos) based variables commonly used to monitor estuaries,utilising estuaries on the North-West Coast of Tasmania (Duck, Montagu, Detention, and Black River). These included: salinity, dissolved oxygen, turbidity, nutrient and chlorophyll a levels for the water-column; and sediment redox, organic carbon content, chlorophyll a and macroinvertebrate community structure amongst the benthos. In addition to comparing reference with impacted estuaries, comparisons were also made across seasons, commensurate with seasonal changes in freshwater river input, and between regions within estuaries (upper and lower reaches) - previously identified in Hirst et al. (2005). This design enabled us to examine whether the detection of impacts (i.e. differences between reference and impacted systems) was contingent on the time and location of sampling or independent of these factors. The data represented by this record was collected in the Black River.

  • Targeted trace elemental analysis was used to investigate the population structure and dispersal patterns of the holobenthic octopus species Octopus pallidus. Multi-elemental signatures within the pre-hatch region of the stylet (an internal ‘shell’) were used to determine the common origins and levels of connectivity of individuals collected from 5 locations in Tasmania. To determine whether hatchling elemental signatures could be used as tags for natal origin, hatchling stylets from 3 of the 5 locations were also analysed.

  • This study aims to undertake a comprehensive survey of the benthic fauna of Port Davey – Bathurst Harbour and adjoining Payne Bay, James Kelly Basin and Hannant Inlet. This will provide important information on the composition and structure of benthic faunal communities and the distribution of any introduced species amongst the benthos. In February/ April 2007 invertebrate faunal communities were sampled at 70 locations throughout the system – with the greatest intensity of sites located within Port Davey, Bathurst Channel and Bathurst Harbour.