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.

Australia is home to a quarter of the world’s cartilaginous fishes (Class Chondrichthyes) with 328 species consisting of 182 sharks, 132 rays, and 14 chimaeras. Australia’s first Shark Action Plan aims to provide a comprehensive and consistent review of the extinction risk of all cartilaginous fishes (hereafter ‘sharks’) occurring in Australian waters, to provide a benchmark from which changes in population and risk can be measured, and to help guide management for their conservation. This Action Plan also serves to raise the profile of their diversity and conservation needs. This volume includes a taxa profile for each of the 328 species occurring in Australian marine and inland waters, including external territories. Each species’ extinction risk was assessed by applying the IUCN Red List Categories and Criteria at the national level. Assessments of extinction risk consider all available information on a species’ taxonomy, distribution, population status, habitat and ecology, major threats, use and trade, and conservation measures. The IUCN Red List Categories and Criteria utilise a series of thresholds to evaluate extinction risk based on population size reduction, geographic range, population size, or the probability of extinction. Species were assessed against the five Red List criteria; to qualify for one of the three threatened categories (Critically Endangered, Endangered, or Vulnerable), a species had to meet a quantitative threshold for that category in any of the five criteria. The overall status of sharks in Australia is characterised by a relatively low level of extinction risk and a high level of secure species. Of the 328 species, 12% are threatened (39 species: 22 sharks, 17 rays; no chimaeras are threatened); 10% are Near Threatened (32 species: 18 sharks, 13 rays, 1 chimaera); 70% are Least Concern (231 species: 123 sharks, 95 rays, 13 chimaeras); and, 8% are Data Deficient (26 species: 19 sharks, 7 rays, no chimaeras are Data Deficient). No species are Extinct or Extinct in the Wild. Each taxa profile specifies two sets of actions for a species: actions to address knowledge gaps, and actions to maintain, secure, and if necessary, recover the population. To improve the ability to accurately assess the status of species, and ultimately, better conserve and manage them, all species treated in this Action Plan require some knowledge gaps be filled. Knowledge gaps are divided into five themes, each of which improves the information base from which to assess status: taxonomy, distribution, population trend, life history, and connectivity. Conservation actions are provided for each species, regardless of the status assigned them in this Action Plan. While threatened species require immediate action to conserve, manage, and recover their populations, Least Concern species also require action to maintain their secure status. Data Deficient species require action to understand various aspects of their population, but since an assessment as Data Deficient acknowledges the possibility that future research may show that a threatened classification is appropriate, action is also needed to minimise or mitigate threats until such time as more information is available to show that the species is not threatened. Finally, an overarching recommendation is provided for each threatened species. This includes the recommendation that five species be considered for listing on the Environment Protection and Biodiversity Conservation Act (EPBC Act), three species be considered for up-listing, and two species be considered for down-listing. An additional 12 threatened species have been identified as priorities for data collection where further data are required to strengthen the evidence-base underlying their status determinations. These species are priorities for research and monitoring to provide data to support inferred or suspected population reductions or continuing declines identified in the Action Plan. The implementation of the recommendations and actions in this Action Plan will require an ongoing and enhanced investment in science and management which will help secure the future of Australia’s sharks, rays, and chimaeras.

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.

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.