IMAS/CSIRO undertook a multibeam mapping campaign in eastern and Southern Tasmania to map shelf waters of the Freycinet, Huon and Tasman Fracture Marine Parks and several reference areas for the Tasman Fracture Park, including waters around Pedra Brancha and South-west Cape. The dataset includes a post-processed transit along the mid-shelf i=of Western Tasmania. The dataset includes raw mutibeam outputs and post-processed data, including Caris Files, xyz data and geotiffs. A data report for this has been produced by CSIRO. The study was intended to increase knowledge of the distribution of habitats within the SE Australian Australian Marine Park network, and at nearby reference areas with similar habitat. This information is required to underpin subsequent biological monitoring of key habitats within the AMP network, and to contrast the observations within parks with nearby fished locations to determine the extent that changes in biological communities are driven by natural vs anthropogenic pressures.

Antarctic krill (Euphausia superba) are a keystone species in the Southern Ocean, but little is known about how they will respond to climate change. Ocean acidification, caused by sequestration of carbon dioxide into ocean surface waters (pCO2), is known to alter the lipid biochemistry of some organisms. This can have cascading effects up the food chain. In a year-long laboratory experiment adult krill were exposed to ambient seawater pCO2 levels (400 μatm), elevated pCO2 levels that mimicked near-future ocean acidification (1000, 1500 and 2000 μatm) and an extreme pCO2 level (4000 μatm). The laboratory light regime mimicked the seasonal Southern Ocean photoperiod and krill received a constant food supply. Total lipid mass (mg g -1 DM) of adult krill was unaffected by near-future levels of seawater pCO2. Fatty acid composition (%) and fatty acid ratios associated with immune responses and cell membrane fluidity were also unaffected by near-future pCO2, apart from an increase in 18:3n-3/18:2n-6 ratios in krill in 1500 μatm pCO2 in winter and spring. Extreme pCO2 had no effect on krill lipid biochemistry during summer. During winter and spring, krill in extreme pCO2 had elevated levels of omega-6 fatty acids (up to 1.2% increase in 18:2n-6, up to 0.8% increase in 20:4n-6 and lower 18:3n-3/18:2n-6 and 20:5n-3/20:4n-6 ratios), and showed evidence of increased membrane fluidity (up to three-fold increase in phospholipid/sterol ratios). These results indicate that the lipid biochemistry of adult krill is robust to near-future ocean acidification.

CSV files of location data (position estimates) for hammerhead sharks tagged with Wildlife Computers miniPAT archival tags and SPOT6 tags. Note that miniPAT data estimates may be up to 100 km (Kevin Lay, Wildlife computers pers comm). Location estimates from archival miniPAT tags also need to be considered against ARGOS location classes (see http://www.argos-system.org/manual/3-location/34_location_classes.htm). Collectively, movements are restricted within state waters with no hammerheads moving across state or International boundaries.

Rock samples were dredged from seamounts in the southern Tasman Sea on the RV Investigator, voyage IN2018_V08

Sea urchins have the capacity to destructively overgraze kelp beds and cause a wholesale shift to an alternative and stable ‘urchin barren’ state. However, their destructive grazing behaviour can be highly labile and contingent on behavioural shifts at the individual and local population level. Changes in supply of allochthonous food sources, i.e. availability of drift-kelp, is often suggested as a proximate trigger of change in sea urchin grazing behaviour, yet field tests of this hypothesis are rare. Here we conduct a suite of in situ behavioural surveys and manipulative experiments within kelp beds and on urchin barrens to examine foraging movements and evidence for a behavioural switch to an overgrazing mode by the Australian sea urchin Heliocidaris erythrogramma (Echinometridae). Tracking of urchins using time-lapse photography revealed urchin foraging to broadly conform to a random-walk-model within both kelp beds and on barren grounds, while at the individual level there was a tendency towards local ‘homing’ to proximate crevices. However, consistent with locally observed ‘mobile feeding fronts’ that can develop at the barrens-kelp interface, urchins were experimentally inducible to show directional movement toward newly available kelp. Furthermore, field assays revealed urchin grazing rates to be high on both simulated drift-kelp and attached kelp thalli on barren grounds, however drift-kelp but not attached kelp was consumed at high rates within kelp beds. Time-lapse tracking of urchin foraging before/ after the controlled addition of drift-kelp on barrens revealed a reduction in foraging movement across the reef surface when drift-kelp was captured. Collectively results indicate that the availability of drift-kelp is a pivotal trigger in determining urchin feeding modes, which is demonstrably passive and cryptic in the presence of a ready supply of drift-kelp. Recovery of kelp beds therefore appears possible if a sustained influx of drift-kelp was to inundate urchin barrens, particularly on reefs where local urchin densities and where grazing pressure is close to the threshold enabling kelp bed recovery.

This resource contains access links to all data collected and and created under the ACE-CRC program. See 'online resources' section of this record for index of all online ACE-CRC data.

Cyclone data was used to develop a spatial model using the intensity and to determine whether Sea Surface Temperature or Tropical Cyclone Heat Potential contributes to the North Indian Ocean cyclone intensity and, if so, how?