The marine waters of Southeast (SE) Australia are one of a series of global ocean-warming hotspots. In this region, the East Australian Current is extending pole-wards, resulting in warming of ocean surface at a rate four times the global average. Many species have extended their distributions southward, with potential changes in local abundance. In addition, climatic extreme events, such as marine heatwaves, are leading to additional impacts in the region. Projections show that these changes, and the associated biological responses, are expected to continue in the next century.

In this hotspot lie important fisheries, providing the bulk of fresh fish to Melbourne and Sydney markets. The Southern and Eastern Scalefish and Shark Fishery (SESSF) has a total catch of about 20,000t and a value above $80 million. Concerns about the ecological, economic and social sustainability of this fishery raised in the public, and by scientists, over the years, have prompted a series of management responses, initiatives and regulations. In the hotspot also lies an Australian Marine Reserve network established to protect and maintain marine biodiversity and ensure the long-term ecological viability of Australia's marine ecosystems.

Observations from the Australian commercial fisheries regulator, the Australian Fisheries Management Authority (AFMA) suggests that the abundance of some species have declined, while others have increased. Additionally, some species that have been historically over-fished do not seem to be recovering despite reduced fishing pressure. The South East Australian Marine Ecosystem Survey will seek to answer the questions:

1. Despite reduced fishing pressure, have fish abundances in the SESSF really declined in 25 years? And if so, why?

2. Are species shifting their ranges to places outside of where they have been historically found, including to the continental slope?

3. What are the prospects for the future?

Comprehensive bio-physical and ecosystem assessments of the shelf were last conducted 25 years ago. This project will repeat the surveys to document changes, and will establish a new baseline for the continental slope. Specifically, it will help answer the broad questions:

1. How and why have fish assemblages and species abundances changed in the southeast ecosystem, and can the causes be mitigated?

2. How does this affect the multiple-use management of the region for fisheries, conservation and biodiversity and the hive of activity from oil & gas, and renewable energy sectors?

Commercial in confidence. To know more about this project please contact FRDC.

Australian fisheries, including trawl fisheries, need to ensure they met legislative requirements to ensure they have no unacceptable impacts on ecosystems. Similarly, the marine ecosystems and its biodiversity need to be conserved and protected. This project links across sustainability and conservation management objectives by building and extending previous works such as FRDC 2003-021 and FRDC 2016-039, works that provide/establish regional and national regionally relevant clarification of the seabed mapping and landscape-scale fishing footprints, and exposure and protection of demersal assemblages with respect to trawling.
Although significant bycatch data are available (mostly for fishes) for some trawl grounds in the region, such data are needed broadly across the study area (including for invertebrates) and there is almost no information on the distribution and abundance of habitats and sensitive habitat-forming benthos. Currently, this lack of adequate biological data is an impediment to completing bycatch and habitat ERAs for these priority areas. Thus, a pre-requisite need is to survey these areas for distribution and abundance of sensitive habitats and bycatch species.
This project will then fill the existing gaps and needs in the southern portion of QLD and north-eastern of NSW with new data & methods and new risk-based management assessments to implement a consistent spatial approach for the conservation management of demersal assemblages applying to all continental shelf trawl fisheries. This will be done in collaboration with researchers in each State, industry and commonwealth managers.
This project proposes to conduct the required distribution and abundance surveys, and then assess whether sensitive habitats and bycatch species are at substantive risk from trawling. If necessary, the project would also evaluate risk-management options that may be proposed, using an objective MSE-type approach. Methods and outputs proposed herein would be comparable with those from the previous GBR Seabed Project (FRDC 2003-021). Previous sampling in the GBR, southern Queensland and northern NSW, would be taken into account.

Commercial in confidence. To know more about this project please contact FRDC.