This unified proposal addresses two needs within the NSW oyster aquaculture industry:
1) The development of a seagrass condition monitoring program that industry can apply going forward, and that is transferable across estuaries,
2) The identification of environmental benefits and impacts of different methods of oyster aquaculture in NSW, and gaps in knowledge, using the standardised The Nature Conservancy framework. Circumstances in which oyster aquaculture is found to have an environmental neutral or positive impact could be used to inform strategic management for industry growth.

By combining these projects, this proposal provides a strategy to help improve industry practice by identifying ways to minimise any potential impacts on seagrass (in particular the endangered Posidonia australis) and document the significant environmental benefits of oyster farming in NSW. This integrated approach is intended to strengthen the industry's social license, influence policy development, and contribute to sustainable aquaculture growth.

SEAGRASS MONITORING:

Posidonia australis is listed as a threatened population under NSW legislation and as an Endangered Ecological Community under the Federal EPBC Act. This seagrass is slow-growing and sensitive to disturbance. It’s found in protected waters of coastal bays and estuaries; water that is also ideal for oyster farming and gazetted by the NSW Government as Priority Oyster Aquaculture Area (POAA). Through the signing of 15-year lease agreements, oyster farmers are authorised to cultivate shellfish and effectively act as stewards of these sensitive areas. Under the NSW Oyster Industry Sustainable Aquaculture Strategy, farmers are required to report any significant changes to seagrass coverage in their leases and this project will help develop methods to enable that to be done effectively.

There are a wide range of oyster farming practices used throughout NSW, and growers employ a variety of different infrastructure, gear types, stocking rates and lease spacing. The interplay between these elements influences the potential impact the lease has on the local environment – including seagrass meadows. Whilst it's accepted that the oyster industry has the potential to impact on seagrass health, the comparative impact of different farming techniques has not been well-recorded. Industry is enthusiastic to voluntarily engage in a program which would assess their potential impact and make voluntary changes to their practices as a result. Failure for industry to respond to these concerns could result in restrictions being placed on farming practice, and the potential removal of gazetted lease areas from the NSW marine estate.

In partnership with growers and with expert guidance from NSW DPIRD researchers, NSW Farmers will facilitate the development of a seagrass condition monitoring program informed by existing methodology, enabling farmers to monitor seagrass distribution & health in their lease areas.

By undertaking monitoring on multiple leases involving different cultivation methodologies, farmers will be able to directly compare their potential impact. This comparison will include quantitative field data such as water depth, degree of movement of infrastructure and indicators of Posidonia health underneath and adjacent to cultivation, and aerial imagery (vegetation mapping) collected regularly by drone will help visually report the coverage of seagrass on lease areas over time

This project will also develop seagrass friendly workplans so that farmers will be able to translate their observations and learnings into a set of practical measures to guide their operation on 'seagrass-sensitive' leases. For example. improvements may involve switching growing infrastructure for the specific conditions on their leases. Other improved practices may include not walking on the seabed to avoid damage to non-visible root systems, reducing basket density, raising basket height, or attending the lease only on high tides with a raised outboard trim. Improving industry practices and awareness will help protect Posidonia beds and provide a strong case for continued industry operation in these areas using best practice guidelines.

Ideally data will be collected from leases where a before / after comparison can be made to determine how changes to cultivation practice can lead to improved outcomes for Posidonia and enable a robust test of any potential impacts of particular infrastructure types on seagrass. Also, monitoring of lease areas should be compared to adjacent controls at similar depths where there has been no oyster cultivation to help interpret seagrass changes relative to any broader estuary patterns.

Whilst the monitoring program will help asssess the potential impact of oyster industry practices on seagrass, it will also be designed to capture the environmental observations of growers. Oyster farmers are on the water every day, and their knowledge of the estuary in which they farm is second to none. Seagrass health is influenced by a multitude of factors, and by documenting events in real time, this may provide useful insights that would otherwise be missed.

APPLICATION OF 'NATURE POSITIVE' FRAMEWORKS:

The increasing demand for sustainable food to support growing populations means there is an increasing need to advance industries with greater positive environmental and social influence. Whilst oysters are themselves small in size, they comprise one of the most sustainable no-feed, no-waste aquaculture operations on the planet which provide additional environmental benefits through the provision of numerous ecosystem services.

To help value, monitor and communicate these advantages, a number of frameworks have emerged in recent years which attempt to standardise and quantify the benefits. These include The Nature Conservancy's Global Monitoring & Learning Framework for Restorative Aquaculture, the Accounting for Nature Framework, and the emerging Nature Repair Market.

Whilst the ecosystem benefits of oyster aquaculture are considered to be broadly substantiated, this information is rarely consolidated, and may not account for variations in species, cultivation method, or regionality. This element of the project will therefore firstly look to consolidate knowledge on the ecosystem services provided by oyster production in NSW using The Nature Conservancy Framework, and identify any potential environmental impacts caused by aquaculture, and in what circumstances. The intention is to identify circumstances in which oyster aquaculture is found to have an environmental neutral or positive impact. This information could then be used to inform strategic management for the best outcomes for the environment and industry growth.

To help summarise and communicate the environmental benefits of NSW oyster aquaculture, a plain English, public facing document will also be developed.