Aquatic Ecology and Ecotoxicology research at CQUniversity focuses on improving monitoring, assessment, management and reporting frameworks, to minimise the impacts of land use on freshwater, estuarine and inshore marine environments. Our researchers include biologists, ecologists, environmental chemists and ecotoxicologists. We conduct interdisciplinary research, frequently collaborating with agricultural scientists, economists and social scientists, and have an ethic of promoting stakeholder engagement, delivering innovative solutions to managing rivers and estuaries in a changing environment.


Active researchers in the Aquatic Ecology and Ecotoxicology group include:

Current RHD students in the Aquatic Ecology and Ecotoxicology group include:

Developing a Mud Crab Indicator for the Gladstone Harbour Report Card

Investigators: Dr Nicole Flint, Dr Emma Jackson, Dr Amie Anastasi, Dr Evan Chua, Dr Jeremy De Valck
Funded by: Gladstone Healthy Harbour Partnership (GHHP)

Mud crabs (Scylla spp.) are key fisheries products in Africa, Asia, Australia and the South Pacific. In Queensland, the total annual catch of mud crabs was approximately 1,000 tonnes worth AUD18.7 million in 2015. Green mud crabs (S. serrata) are recreationally and commercially important in Gladstone Harbour and are an iconic seafood item, with cultural value to some Indigenous Australian peoples. As a result of their commercial importance to the fishing and aquaculture industries, the biology, ecology and biochemistry of mud crabs is relatively well known. Mud crabs have potential as biological indicators as they are sedentary, easily identifiable, abundant, long-lived, resistant to handling stress and tolerant to environmental variations.

Study aims

The primary aim of this study was to develop a mud crab indicator, with appropriate baselines and scoring systems for use in a waterway health report card.

Research Report: Flint, N., Anastasi, A., De Valck, J., Chua, E., Rose, A., and Jackson, E.L. (2017) Developing mud crab indicators for the Gladstone Harbour Report Card: Project ISP015-2017. Report to the Gladstone Healthy Harbour Partnership. CQUniversity Australia, Queensland. Available at:

Developing Fish Health Indicators for the Gladstone Harbour Report Card

Investigators: Dr Nicole Flint, Dr Emma Jackson, Dr Amie Anastasi, Associate Professor Andrew Irving, Dr Jeremy De Valck
Funded by: Fisheries Research and Development Corporation (FRDC) and the Gladstone Healthy Harbour Partnership (GHHP)

Fish are key biological indicators of environmental contamination, as they are continuously exposed, ubiquitous in aquatic ecosystems, and play an important ecological role. Fish health indicators, such as morphometry, gross pathology, histopathology, fish parasite load and diversity, or chromosomal mutations, provide information on the cumulative impacts of various human activities on aquatic environments.

Study aims

  • To review and identify suitable methods to monitor fish health in Gladstone Harbour.
  • To develop and implement a data collection approach to monitor fish health in Gladstone Harbour that is both cost-effective and suitable for a fish health indicator.
  • To evaluate the potential to adapt and transfer the methods and indicators developed to monitor fish health in other estuaries and ports in northern Australia.
  • To develop baselines and scoring systems for the fish health indicator(s) and apply them to the Gladstone Harbour Report Card.

Offstream Watering Points to Reduce Cattle Impacts on Riparian Zones

Investigators: Mrs Julie-Ann Malan, Dr Nicole Flint, Professor David Swain, Dr Emma Jackson, Associate Professor Andrew Irving
Funded by: Fitzroy Basin Association and CQUniversity Australia

Land clearing and agricultural practices have contributed greatly to water quality concerns for freshwater catchments and the Great Barrier Reef lagoon.  Best management practices for grazing activities, such as providing off-stream watering points (OSWP), have been recommended to improve water quality. It is commonly assumed that by installing an OSWP, the number of cattle, or the frequency or duration of visits by cattle to the riverbank will be reduced. However, there is a limited understanding and a lack of quantitative data linking in-stream water quality to the installation of OSWPs. Environmental and social factors may influence how cattle use OSWPs and it is currently unclear whether such factors can be manipulated to reduce visitations to streams. This research project will seek to evaluate the effectiveness of installed OSWPs in the Fitzroy Basin, determine how cattle use OSWPs, and quantitatively link these outcomes to in-stream water quality and riparian condition, providing recommendations for graziers and natural resource management groups.

Study aims

  • Review and evaluate the strategic placement of OSWPs and how cattle use them
  • Provide recommendations to assist in optimising the placement of OSWPs to improve the riparian condition and in-stream water quality.
  • Provide new data on best practice grazing land management for natural resource management groups and graziers.

Journal Article: Malan, J-A., Flint, N., Jackson, E.L., Irving, A.D., and Swain, D.L. (2018) Offstream watering points for cattle: Protecting riparian ecosystems and improving water quality? Agriculture, Ecosystems and Environment256: 144-152.

Development of a Toolbox for Fish Health Assessment in Aquatic Ecosystems Associated with Coal Industries

Investigators: Dr Nicole Flint, Dr Evan Chua, Dr Scott Wilson, Dr Sue Vink
Funded by: Australian Coal Association Research Program (ACARP)

Biological indicators provide a comprehensive assessment of ecosystem health, capture cumulative impacts and represent key assets that the community can identify with. Fish are the dominant organisms in terms of biomass, feeding ecology and significance to humans, in aquatic ecosystems. In comparison to fish from the Northern Hemisphere, there is limited information on the environmental tolerances of tropical Australian freshwater fish species, and most current information is circumstantial, derived through field observations of water quality and the fish species present at the time of sampling. Whilst the tolerance of various Australian freshwater fish species to commonly monitored stressors such as electrical conductivity, turbidity, nutrients and low dissolved oxygen concentrations have been documented in this way, there is even less available data on the tolerance of freshwater species to environmental toxicants such as pesticides, metals and hydrocarbons. There is, however, a large and increasing body of literature addressing these impacts for freshwater fishes globally. There is a need for practical indicators of fish health that are demonstrably applicable to monitoring in coal mining regions of the Fitzroy Basin, to improve aquatic ecosystem health assessments and inform regional water management.

Study aims

This study aimed to develop practical fish indicators suitable for deployment in remote rural monitoring programs and for reporting on waterway health, by:

  • Investigating and testing existing indicators of fish assemblage health in the Fitzroy Basin;
  • Designing new indicators relevant to mine-associated waters of the Fitzroy Basin; and
  • Developing a rapid fish health assessment toolbox applicable to the Fitzroy Basin.

Research Report: Flint, N., Chua, E., Wilson, S., and Vink. S. (2017). Development of a toolbox for fish health assessment in aquatic ecosystems associated with coal industries. Australian Coal Association Research Program Project C24029. CQUniversity Australia, Queensland.

Journal Article: Chua, E.M., Flint, N., Wilson, S.P., Vink, S. (2018) Potential for biomonitoring metals and metalloids using fish condition and tissue analysis in an agricultural and coal mining region. Chemosphere 202, 598-608.

Gladstone Healthy Harbour Partnership


Gladstone Healthy Harbour Partnership was established in 2012/13 to report on the health of the Gladstone Harbour. There are 25 organisations involved that comprise government at all levels, community groups, industry groups and science groups and they have been established to report back to the public what is actually happening with the health of the harbour.

Some of this is dealing with water quality, of course, but it’s things that live in the water and corals and seagrass and mangroves, fish is really important so that’s assessed. Mud crabs and then turning to the other aspects, the report card includes an assessment of economic factors relevant to the harbour and Gladstone, of the social issues around the community and the cultural issues, which includes both indigenous culture and the wider broader community.

With the help of Central Queensland University, we’ve been able to do a lot of projects in regards to economics, social, cultural factors and also environmental factors. What we try and do is produce a report card that looks after those four areas with 97 measures to report on those indicators, back to the community and government on the health of the harbour. Central Queensland University has played an integral role in that development of the projects and they also supplied the Chair of the Independent Science Panel, John Rolfe.

The university’s had a long involvement with PCIMP, the Port Curtis Integrated Monitoring Program, that helps to identify how the water quality is in the harbour, and then we have researchers like Nicole Flint, who are working with mud crabs and fish and doing some of the annual science that informs the health of the harbour.

We’ve produced five report cards since we established the Gladstone Healthy Harbour Partnership. An interim report and then four report cards since then. We’re pretty close to getting it really in that operational phase where we’re not going to change it too much going forward. That’s a report card that not only we can use, but is also being duplicated along the east coast of Queensland. In the years ahead there will be a common report card for all of the Queensland Great Barrier Reef areas that we can all look at, compare and know exactly what's occurring in each area.

The focus of the research project that we’ve been doing for the Gladstone Healthy Harbour Partnership has been developing a new mud crab indicator. This is a new project that hasn't been attempted before. Mud crabs have previously been suggested as indicators of estuary health in other parts of the world and also in other parts of Australia, but no-one’s ever developed an indicator that can be consistently monitored through time to provide information relating to the condition of mud crabs in one particular area. In 2018, we’re again monitoring mud crabs in Gladstone Harbour and success for this year will mean we’re further developing the indicators and also producing scores and grades again for how well mud crabs are going in Gladstone Harbour.

The research is really important because it’s absolutely imperative that the community and the government get one message about the health of the harbour. Throughout the early 2000s, there were mixed messages going to all groups about the health of the harbour. Since we’ve established doing a report card in 2013, we’re now hopefully giving one clear message to all the community about what the health of Gladstone Harbour is, and the projects with Central Queensland Uni have played a key role in that message.