EARTH SCIENCE | AGRICULTURE | AGRICULTURAL AQUATIC SCIENCES | FISHERIES
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The threatened status of shellfish reefs has been well established globally (e.g Beck et al 2011) however the ecological consequences of these losses is still largely unknown. In Australia, shellfish reefs are one of the most imperilled marine habitat types (Gillies et al 2018), due to historical overharvest and widespread eutrophication of coastal waters through the use of fertilizers, livestock and human waste. Marine bivalves are important ecosystem engineers providing habitat, shelter and a food source for other species in benthic soft-sediment environments. In addition, filter-feeding bivalves link benthic and pelagic components of ecosystems through filtration and excretion. Through their filter feeding, they produce large amounts of faeces (digested seston) and pseudofaeces (rejected particles bound up in mucus) which are deposited on the benthos. This process brings energy and nutrients from the pelagic system to the benthic system (bentho-pelagic coupling). The removal of large quantities of seston can serve an important ecosystem function by improving water quality and clarity. The filtration of water performed by bivalves has been demonstrated to reduce water turbidity, improving light penetration and thereby enhancing growing conditions for seagrasses (Wall et al 2008). In systems where healthy populations of bivalves remain, they can filter a volume equivalent or larger than the entire estuary volume within the residence time of the water (zu Ermgassen et al 2013). While such densities of oysters are rare today, this highlights the critical ecosystem services that are lost when oyster reefs decline. Furthermore, it demonstrates the potential functions that can be regained through oyster reef restoration. Given the increasing awareness of the decline of these ecosystems, interest in restoration efforts to restore critical ecosystem functions has been growing. However, conservation and restoration decision making is underpinned by reliable quantification of relevant ecosystem services (zu Ermgassen et al 2016). For example, there are plans to restore some of the natural oyster reefs of Sydney Rock Oyster (Saccostrea glomerata) in Port Stephens, New South Wales. One of the main drivers motivating this restoration project is restoring lost ecosystem services. The filtration rates of Australian oysters has been demonstrated in aquarium studies using filtered water augmented with algae, yet little is known about filtration and biodeposition rates of oysters using raw seawater. In this study, we provide the first evaluation of the filtration and biodeposition rate of four species of bivalves using raw seawater, providing a proxy for natural biodeposition rates. As such, this study provides a first indication of the filtration/nutrient cycling function that may be restored following oyster restoration efforts.
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This record relates to recreational use patterns from surveys with recreational boaters at 12 locations around Australia across 2019-2020. The collected recreational use patterns are intended to be indicative of use levels for various marine areas. Use patterns were recorded during face-to-face surveys at boat ramps using gridded maps upon which boaters indicated areas they had visited in the last 12 months along with approximate percentages, indicating the relative time spent at each location. Data is supplied as modelled frequency of recreational boating trips (per grid cell per year), based on aggregated boat ramp survey data.
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Data were collected by third-year students on a KSA324 field excursion down the D'Entrecasteaux Channel, on the IMAS vessel Noctiluca. The purpose of the trip was for students to learn how to collect various common types of oceanographic data and work on a research vessel. The study was designed to assess the impact of finfish farming in the Channel on local nutrient levels and water quality. The Tasmanian Environment Protection Authority (EPA) methods for water quality monitoring around finfish farms (Ford 2021, p. 6 – 18) were replicated as closely as possible. The null hypothesis for this study was that, on the 17/04/2023, all measured physico-chemical and biological factors were not significantly above the levels specified by the EPA guidelines (Ford 2021, p. 6 – 18), in any of the four stations measured. These four stations were chosen because they were all further than 35 metres beyond the boundary of any finfish farms’ Lease Area, as specified by the EPA guidelines document (Ford 2021, p. 6). The precise latitudes and longitudes of these stations are as follows: M1 (-43.059295, 147.345047); M2 (-43.056057, 147.291386); M3 (-43.123841, 147.290882); M4 (-43.133534, 147.326519). The dataset includes measurements of temperature, conductivity, oxygen concentration, pH, turbidity, fluorescence and pressure taken by the CTD rosette. Depth, density, practical salinity, absolute salinity and conservative temperature were derived and also included. The dataset also contains bottle sample measurements of oxygen, pH and alkalinity, as well as both the total and dissolved concentrations of ammonia, NOx, nitrite, phosphate and silicate. Chlorophyll concentration, total plankton cell counts, and counts of only Gymnodinium catenatum (a toxic, invasive dinoflagellate) cells were also included in the dataset. The dataset also contains the Secchi depth at each station. Empty cells are indicated by “NA”. ODV data flagging convention was used: 0 = good quality; 1 = unknown quality; 4 = questionable quality; 8 = bad quality. Reference: Ford, W (Director for the Environment Protection Authority) 2021, Environmental Licence No. 9869/3, Environmental Licence under the Environmental Management and Pollution Control Act 1994, pp. 6 – 18.
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Google Earth KMZ files of hammerhead sharks tagged with Wildlife Computers miniPAT archival tags and SPOT6 tags. Files of animals tagged with MiniPAT tags include an MELE polygon, which is the 'Maximum extent of location estimates', that is, a polygon enclosing all position estimates at the maximum error level (100 km). Collectively, movements are restricted within state waters with no hammerheads moving across state or International boundaries.
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Carbon and nitrogen isotope data for J. edwardsii lobsters from eight sites in SE Australia.
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Policy and decision makers often seek guidance as to the benefits of conservation and repair of coastal seascapes, to justify and underpin any potential investments. Much is already known about the broad habitat and nursery values of seascapes among the science community, but there is also a need for estimation of clear and unambiguous market-based benefits that may arise from investment in repair. Recognising that this economic knowledge is imperfect for Australian seascapes, three case studies spanning tropical, subtropical and temperate environments explored the benefits in question. The case studies focus on saltmarsh habitats in particular, which have received very little investment in repair despite subtropical and temperate coastal saltmarsh listed as vulnerable ecological community under Australian Federal legislation. A subset of economically important species and conservative judgments were used to characterise the minimum potential economic benefit. For each of the case studies the conclusion was that while the biological information will remain imperfect, the business case for investment in the repair and conservation of coastal seascapes is compelling. We outline priorities for further research to make the business case more tangible to policy makers, stakeholders and the general public.
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Estimates of the value of habitats can provide an objective basis for the prioritisation of conservation and restoration actions. Bivalve habitats, three-dimensional structures made of high-densities of bivales (most often oysters or mussels), their shells and other organisms, used to be a dominant habitat found in temperate and subtropical coastal waters. These habitats, provide a suite of ecosystem services such as habitat provision and food supply for many species, substrate stabilisation and shoreline protection, and water quaility improvements through their filter feeding. Bivalve habitat restoration is increasingly seen as an opportunity to return lost ecosystem services. In Australia, there is growing interest in bivalve habitat restoration, but there is a knowledge gap in regards to the services they provide. Here, we determined the habitat value of a historically dominant oyster species in Australia, Saccostrea glomerata. At remnant soft-sediment oyster reefs at four locations we estimated density, biomass, productivity and composition of mobile macroinvertebrate communities and compared these with adjacent ‘bare’ soft sediments, which typically replace ecologically extinct oyster reefs. The oyster reefs had a distinct assemblage of macroinvertebrates, with 30% higher densities, 5 times the biomass and almost 5 times the productivity of adjacent bare sediments. Infauna macroinvertebrate productivity was more than twice as high below oyster reefs, suggesting these reefs facilitate infaunal productivity. Crustaceans, an important food source for small fishes, were 13 times more productive on oyster reefs compared to adjacent bare sediments. These results demonstrate that oyster reefs provide an important habitat for macroinvertebrates and that restoration efforts are likely to provide significant returns in enhanced productivity.
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This record relates to outputs from a series of socio-economic surveys conducted nationally to benchmark awareness and perceptions towards the Australian Marine Parks. This includes a general public survey, a boat ramp survey (focussed on boat-based recreational users), a targeted survey (focussed on members of fishing, boating and yacht clubs) and a charter operator survey (focussed on fishing and eco-charter operators). All surveys were conducted across 2019-2020. Raw data could not be made available. Aggregated survey data is supplied as summary plots in the final report: https://www.nespmarine.edu.au/document/social-and-economic-benchmarks-australian-marine-parks
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This data describes various acanthocephalan, nematode and helminth parasites identified on elasmobranchs caught between 2015 and 2018 at a number of sites around Australian. All parasite and host data is contained with tables in publications linked to this record (see Supplementary Information and Online Resources section).
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Meta data of all tagged hammerhead sharks detailing tag dates, locations, and shark biological details.
IMAS Metadata Catalogue