Monitoring the Health of Aquatic Ecosystems

The University of Newcastle actively monitors aquatic ecosystem health through research programs, partnerships, and community science initiatives. In 2025, the University combined local freshwater habitat assessments, coastal monitoring research and collaborative environmental science to better understand the condition of aquatic ecosystems in the Hunter and Central Coast regions. This work provides practical information about water quality, biodiversity and human pressures on waterways.

Monitoring local aquatic environments in 2025

Freshwater monitoring in campus catchments and the Williams River

During Semester 2, 2025, the University’s Catchment and Water Resource Management course (ENVS2009) at Callaghan and Ourimbah set out practical monitoring of nearby freshwater environments. Its published teaching schedule included campus catchment water-quality and habitat assessments, field measurements, sample collection and analysis, followed by a compulsory Williams River field excursion focused on water quality and aquatic habitat condition. Students were also scheduled to process water and macroinvertebrate samples and identify aquatic invertebrates to help interpret ecosystem health.

These field-based activities connect freshwater ecology to the condition of waterways associated with University campuses. By measuring environmental characteristics and biological indicators, the course provides a way to assess habitat quality, recognise potential pressures and develop evidence-based recommendations for catchment management.

Monitoring underwater sound and marine habitats

In 2025, University of Newcastle researcher Brittney Valenzisi and colleagues, including Professor Troy Gaston and Associate Professor Megan Huggett, published studies of underwater soundscapes in New South Wales coastal waters. Their work used hydrophones and ecological analysis to characterise natural sounds and noise associated with human activities. One study, published in June 2025, compared underwater soundscapes in different management zones, including habitat used by marine species in the Port Stephens region; a further 2025 study considered soundscapes associated with the endangered grey nurse shark.

This research helps reveal where vessel and other human-generated sounds may alter the acoustic environment used by marine wildlife. The findings provide information for monitoring and managing pressures on local coastal ecosystems. The cited field recordings pre-date 2025; the research analysis and peer-reviewed publications provide the 2025 contribution.

Planning long-term monitoring of Central Coast ocean outfalls

The University also contributed to the design of an aquatic monitoring programme with Central Coast Council during the 2024–2025 reporting period. Led by Professor Troy Gaston, the multidisciplinary team developed an approach for assessing three coastal wastewater ocean outfalls, combining water-quality testing, microbial source tracking, seabed-habitat assessment, remote sensing, underwater cameras and environmental DNA (eDNA) techniques. The programme was designed to help detect potential changes in marine biodiversity and environmental condition around treated wastewater discharges, as detailed in the 2024–2025 Newcastle Institute for Energy and Resources Annual Report.

The University’s 2025 contribution was the monitoring design and technical groundwork, rather than completion of the subsequent field-monitoring programme. Field surveys began in January 2026, following the reporting period, according to the 2026 University project update.

Complementary research and community monitoring

Sydney rock oysters as indicators of estuarine health

In 2025, University of Newcastle researchers contributed to a published review of Sydney rock oysters as long-term indicators of environmental change in Australian estuaries. The review described how oyster aquaculture and associated scientific studies have identified threats from microbial contamination, metals, pesticides, PFAS and other pollutants. It also highlighted the value of biological monitoring for understanding estuarine health and managing risks to these ecosystems. This was a research contribution examining existing monitoring evidence, not a claim that the University operated the entire oyster-industry monitoring network.

Freshwater and catchment fieldwork in the Cook Islands

In September 2025, Professor Troy Gaston and Dr Alex Callen undertook freshwater and catchment field assessments on Rarotonga, working with the Cook Islands National Environment Service and local stakeholders. Activities included field investigation and freshwater macroinvertebrate sampling to strengthen understanding of catchment condition and biodiversity. The field visit and the collaboration supported locally informed environmental management.

^{Above: Professor Troy Gaston undertaking water quality monitoring on Rarotonga}

This project demonstrates the University’s wider expertise in environmental monitoring and capacity-building across the Pacific. It complements, rather than replaces, the University’s monitoring of ecosystems near its Australian campuses.

Building on earlier local ecosystem research

The University’s 2024 Brisbane Water study, led by PhD researcher Molly Grew, used drone imagery, aerial photography and three-dimensional modelling to survey stingray feeding and resting pits. The research estimated that estuary stingrays may move more than 21,000 tonnes of sand annually, illustrating their contribution to sediment turnover and oxygenation of estuarine habitats. This remains a valuable historical example of field-based ecological assessment in the Central Coast region.