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 record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project A13 - "Estimation of population abundance and mixing of southern right whales in the Australian and New Zealand regions". For specific data outputs from this project, please see child records associated with this metadata. -------------------- A comprehensive understanding of the population abundance and degree of spatial connectivity of southern right whales in Australian waters is currently lacking. This limits assessments of the species recovery and understanding of the nature and degree of difference between the south-eastern and south-western Australian populations. This project will provide, for the first time, an abundance estimate of the total Australian population of southern right whales. It will also investigate the connectedness of whales that utilise breeding areas on the eastern, southern and western coasts of Australia. Information provided by this project will allow the Australian government to better evaluate progress made against the Conservation Management Plan for southern right whales and ensure conservation efforts for the species are effectively coordinated at the regional level. Planned Outputs • Data summaries for populating models used to estimate abundance and connectivity • An estimate of population abundance at the national scale and associated uncertainty • An evaluation of movement and spatial mixing across southern Australia

This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project D5 - "A standardised national assessment of the state of coral and rocky reef biodiversity". For specific data outputs from this project, please see child records associated with this metadata. -------------------- This project will involve integration of a national suite of reef biota Underwater Visual Census (UVC) monitoring datasets (Reef Life Survey (RLS), University of Tasmania (UTAS), Australian Institute for Marine Science (AIMS), Parks Victoria (PV), SA Department of environment, water and natural resources (DEWNR)) to provide a comprehensive update to the state of Australian Reefs report for the next national State of the Environment Report. Maps and indicator trends will show changes in the health of rocky and coral reefs nationally from 2005 to 2020. The update will include addition of a new index which summarises the population trajectories for 600-1000 reef species nationally. Individual species trajectories will provide the only threat status information for the majority of these species, assisting future listing of previously unassessed species if significant declines are detected. Planned Outputs • Maps and trends in SoE indicators • Raw data underlying SoE analyses (data use agreement must be signed with AIMS for access to that data) • Various scientific papers

This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub project E7 - "Assessing the feasibility of restoring giant kelp beds in eastern Tasmania". For specific data outputs from this project, please see child records associated with this metadata. -------------------- This project will extend an externally funded project conducted through UTAS commencing in 2018 to select for thermally tolerant and low-nutrient-tolerant giant kelp (Macrocystis pyrifera) genotypes, and to examine effects of acclimation of selected genotypes by pre-exposure to warm, nutrient-poor conditions. The proposed project will outplant pre-exposed selected genotypes of giant kelp as micro-sporophytes in an experiment with and without provision of an added source of nutrient. The work is designed to assess the feasibility of this approach as a means to develop minimum patch sizes for giant kelp that can be self-replacing and self-expanding, thus providing restoration and future climate-proofing options for this EPBC-listed marine community. Planned Outputs • Experimental data from macrocystis restoration • Final report

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.

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?

The AUStralian Tidal Energy (AUSTEn) project was a three year project (2018 - 2020) funded by the Australian Renewable Energy National Agency (agreement number G00902) led by the Australian Maritime College (University of Tasmania), in partnership with CSIRO and University of Queensland. The project had a strong industry support (Atlantis Resources Limited, MAKO Tidal Turbines Ltd, Spiral Energy Corporation Ltd). The aim of the project was to assess the technical and economic feasibility of tidal energy in Australia, based on the best understanding of resource achievable. For further information and output of the project, please visit the AUSTEn project website www.austen.org.au.

The AUStralian Tidal Energy (AUSTEn) project was a three year project (2018 - 2020) funded by the Australian Renewable Energy National Agency (agreement number G00902) led by the Australian Maritime College (University of Tasmania), in partnership with CSIRO and University of Queensland. The project had a strong industry support (Atlantis Resources Limited, MAKO Tidal Turbines Ltd, Spiral Energy Corporation Ltd). The aim of the project was to assess the technical and economic feasibility of tidal energy in Australia, based on the best understanding of resource achievable. For further information and output of the project, please visit the AUSTEn project website www.austen.org.au.

This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project D6 - "Socioeconomic benchmarks". For specific data outputs from this project, please see child records associated with this metadata. -------------------- Social and economic values are key drivers for marine science and marine policy but are too rarely integrated with marine biodiversity monitoring programs. In close consultation with Parks Australia (PA) we will review existing metrics used to survey social and economic values associated with marine parks. This review will include consulting with national and international expertise and actively consulting with State and other Commonwealth agencies, some of whom are currently conducting reviews or have existing frameworks for surveying social and economic values (e.g Great Barrier Reef Marine Park Authority (GBRMPA), NSW Department of Primary Industries (DPI)). In collaboration with national partners and PA we will organise a national methods workshops to discuss and refine metrics and methods to quantify social and economic benchmarks for State and Australian Marine Parks (AMPs) and produce Standard Operating Procedure’s (SOP) relevant to AMPs taking into consideration the Department of the Environment and Energy’s (DoEE’s) environmental accounting processes and PA’s Monitoring, Evaluation, Reporting and Improvement (MERI) framework. Planned Outputs • SOP for measuring social and economic metrics for AMPs • Final report on essential (key) AMP social and economic metrics • Summaries of research and surveys made available through the Marine Parks Science Atlas

Australia has established a network of 58 marine parks within Commonwealth waters covering a total of 3.3 million square kilometres, or 40 per cent of our exclusive economic zone (excluding Australian Antarctic Territory). These parks span a range of settings, from near coastal and shelf habitats to abyssal plains. Parks Australia manages the park network through management plans that came into effect for all parks on 1 July 2018. Geoscience Australia is contributing to their management by collating and interpreting existing environmental data, and through the collection of new marine data. “Eco-narrative” documents are being developed for those parks, where sufficient information is available, delivering collations and interpretations of seafloor geomorphology, oceanography and ecology. Many of these interpretations rely on bathymetric grids and their derived products, including those in this data release. Geoscience Australia has developed a new marine seafloor classification scheme, which uses the two-part seafloor mapping morphology approach of Dove et al (2016). This new scheme is semi-hierarchical and the first step divides the slope of the seafloor into three Morphological Surface categories (Plain, <2°; Slope, 2-10°; Escarpment, >10°). This classification was applied to the portion of the Beaman and Spinnocia (2018) 30 m grid within the marine park. Beaman, R.J. and Spinoccia, M. (2018). High-resolution depth model for Northern Australia - 30 m. Geoscience Australia. Dove, D., Bradwell, T., Carter, G., Cotterill, C., Gafeira, J., Green, S., Krabbendam, M., Mellet, C., Stevenson, A., Stewart, H., Westhead, K., Scott, G., Guinan, J., Judge, M. Monteys, X., Elvenes, S., Baeten, N., Dolan, M., Thorsnes, T., Bjarnadóttir, L., Ottesen, D. (2016). Seabed geomorphology: a twopart classification system. British Geological Survey, Open Report OR/16/001. 13 pages. This research is supported by the National Environmental Science Program (NESP) Marine Biodiversity Hub through Project D1.