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Understanding water quality risk for the sustainable and efficient production of pacific and sydney rock oysters

BUDGET EXPENDITURE: $85,791

PRINCIPLE INVESTIGATOR: Assoc. Prof. Shauna Murrary

ORGANISATION: UTS

PROJECT CODE: 2021-075

PROJECT STATUS: Current

 

WHY IS THE RESEARCH BEING UNDERTAKEN? 

Water quality is an important determinant of the success of oyster farming, and can be impacted by many 
factors. The top four ranked problem priorities by NSW oyster farmers in a recent industry survey were: 
prediction of harmful algal blooms (HABs); longer harvest opening times; reduced stock mortalities/disease; 
and more information of stock growth/production. The threat of disease and productivity loss for the industry 
is particularly prevalent in 2021 given post-bushfire impacts and climate forecasts. 


To ensure a safe product, farmers must respond to instructions set by regulators following ASQAAC 
guidelines, such as the NSW Food Authority, and otherwise be as reactive as possible to disease/HAB risks. 
Using a backlog of environmental, biological and oyster growth data from the Oyster Transformation Project 
(a multidisciplinary collaboration between oyster farmers, researchers (UTS, DPI Aquaculture and Fisheries), 
regulators (DPI Biosecurity and Food Safety), industry partner The Yield Technology Solutions Pty Ltd (now 
ICT International), Hunter Local Land Services and the CRC Food Agility), this project aims to deliver tailored 
prediction of water quality and Sydney Rock and Pacific oyster production in the Georges and Hawkesbury 
Rivers. As part of Phase 2 of the Oyster Transformation project, this project will expand to include 15
estuaries in NSW as well as Western Australia. Sensor deployment and biological sampling will begin in the 
Macleay River, NSW, as part of Phase 2 of this project. Phase 2 of this project will see the development of a 
suite of modelling tools based on water quality for estuaries and oysters.


In South Australia, issues such as diseases (POMs in Adelaide Harbour, SAMs) and food safety risks (HABs, 
closures due to rainfall, low salinity, sewage spills, etc) are similarly of concern for oyster farming. In 
Tasmania, seasonally recurrent outbreaks of POMs occur, as well as HABs of Alexandrium catenella, 
closures due to rainfall, sewage spills and low salinity occur. As such, the modelling done in these example 
estuaries will be directly applicable to the situation in other states.

The Macleay River is a typical oyster farming estuary in that it is impacted by poor water quality from time to 
time. In particular, the Macleay is an example of the range of water quality issues that can impact oyster 
farming, as in the past 2 years, it has been effected by: flooding, bushfire runoff, acid sulphate runoff, deoxygenated water, QX disease, low salinity, and sewage spills. As in all NSW estuaries, it also has fluctuating 
levels of potentially harmful algal species occasionally.


Little water quality data exists yet for this estuary, despite the fact that it has suffered recent severe ‘black 
water’ events. This project will represent the first time that very detailed water quality information will be 
collected and analysed from this estuary, in order to determine predictive models to improve the ability of 
oyster farmers to respond to poor water quality events. 


For this reason, this estuary will serve as a case study for the range of issues that can impact oyster farming 
in Australia. This site will be used as an example of an approach to managing water quality using high quality 
data. In addition, the Georges River estuary and the Hawkesbury estuary experience other issues and have 
active growth of Pacific oysters rather than Sydney Rock oysters. The Hawkesbury has experienced a large 
scale POMs outbreak which devastated industry. The Georges River has been an experimental site for oyster 
research by the NSW DPI and Universities for decades, and has an extensive collection of metadata 
associated with it. 


Data from these three estuaries is appropriate and can be useful to oyster growers in Tasmania and South 
Australia, as we will examine the impact on water quality impacting a Pacific Oyster growing estuary, and 
because water quality issues such as impact these estuaries are typical examples of the issues impacting 
this industry nationally. Tasmanian and South Australian oyster farmers will benefit from the information 
about how a real time sensor network and associated biological data collection can be used to model water 
quality issues of concern to industry, as well as being used for industry regulatory purposes.

OBJECTIVES:

  1. Collect new biological and physical data from the Macleay estuary using a real time temperature and 
    salinity sensor, oysters and water samples. 

  2.  Conduct modelling and analysis of real time sensor data from estuaries in comparison to biological 
    data, showing the impact of water quality variables, rainfall and disease on oysters in estuaries farming 
    Sydney rock oysters and Pacific oysters.

  3.  Discuss outcomes with oyster farmers, regulators, government, researchers, councils other industry 
    groups. Discuss outcomes with app developers able to incorporate the models outcomes of the project 
    into their products.

  4. Produce a guidance document outlining the way in which real time environmental sensing data is 
    acceptable and applicable for use by shellfish safety regulators.

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