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25 Mar 2016



Investigating mussel population declines in Yuku Baja Muliku Sea Country

Project summary

This project directly addresses Yuku Baja Muliku (YBM) concerns that their mussel stocks are declining. YBM Rangers and scientists will:

  1. scientifically describe YBM mussel resources;
  2. collate community information about the mussel beds;
  3. build YBM capacity to collect long-term monitoring data; and
  4. begin to identify possible causes of the declines.     


Mussels are an important environmental asset and traditional resource for the YBM People and many Indigenous Australians. However, mussels are particularly sensitive to environmental changes and can be severely affected by poor water quality. Freshwater mussels across Australia are facing numerous threats and several species are threatened. Unfortunately, scientific knowledge of Australian mussels is extremely limited, particularly in Australia’s northern monsoonal regions. This knowledge gap compromises their management and sustainability. At this stage, the taxonomy and ecology of the Annan River mussel beds are unknown, as is their conservation status and significance. This project would comprise an important baseline scientific study of these resources.

The Annan River mussels are culturally important to the YBM community, and elders are particularly concerned that mussel populations in their Sea Country are declining. Some believe that declining water quality is the cause. The lack of scientific information about these resources may be compromising their management. At this stage, even basic information such as the species composition of these mussel beds is unknown. The YBM community has approached JCU researchers to form a collaboration of scientists and managers to scientifically assess the mussel beds, help YBM establish a monitoring program, and to begin investigating possible causes of the reported declines.


The mussel bed declines are threatening a culturally important food source for the YBM community. While the causes of the decline are unknown, mussels can be affected by pollution and sedimentation, both of which may be occurring in the Annan river. Known existing threats in YBM country include erosion and pollution, including potential leaching of toxic chemicals.


The research team will visit YBM Country on a 7-9 day trip to collect initial samples and data, and train YBM Rangers in survey methods. During this Baseline Survey, the team will meet with community members and elders to record knowledge of values and traditional knowledge on YBM mussels. The team will also collate the available environmental data for the Annan River and catchment.

While on YBM country, the project team will:

  • Map YBM mussel locations;
  • Select and photograph survey sites;
  • Estimate mussel population density at each survey site by counting mussels in random quadrats;
  • Estimate mussel population structure - Measure random sample of mussels for size (length x width x height);
  • Dissect 10-20 mussels from each site to determine sex and reproductive status;
  • Retain samples for morphometric and genetic analyses to determine mussel species composition;
  • Collect baseline water quality parameters (temperature, dissolved oxygen, salinity, pH, conductivity and turbidity) with YSI Handheld meters. Hourly, depth stratified water quality profiles will be collected at key survey sites to document variability.
  • Training YBM rangers in mussel population surveys and water quality monitoring.
  • Audio-visual documentation and reporting and recording of project activities.

Ongoing monitoring will be conducted by YBM rangers using innovative mobile technology. YBM’s collaboration with Cultural Systems Solutions will develop a mobile data collection and management system for monitoring tropical water quality and mussel bio-monitoring. Rangers will use portable hand-held devices to collect and upload data.

Project location

Data and Resources


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