Aquatic biodiversity conservation and management

This research helped to identify priority areas and actions for the conservation of aquatic biodiversity in Northern Australia. It included a number of sub projects that generated new knowledge on; the distribution of freshwater species across northern Australia; estuarine fish in Kakadu National Park; and how freshwater fish would respond to a number of threats including climate change.   It also developed new approaches to improve planning for freshwater ecosystems.

Northern Australian rivers, wetlands and estuaries support a unique and diverse array of aquatic plants and animals that are highly valued by people.  The high conservation values of northern Australia’s tropical rivers, even in protected areas, are under increasing threat from feral animals, weeds, overgrazing, catchment clearing, fire, increased development and climate change.

Knowledge on how aquatic biodiversity is distributed across the landscape and on the processes that sustain it is vital for effective conservation and management.  An effective framework is needed to bring together complex information on what actions to undertake and where to undertake them for the greatest conservation benefit of the resources invested.

• A comprehensive survey of estuarine fish within the Alligator Rivers region in Kakadu National Park in both wet and dry seasons and using a variety of sampling methods;
• an assessment of the effects of sea level rise on floodplain freshwater fish species in Kakadu National Park;
• incorporating ecological and evolutionary processes into a freshwater conservation planning recommendations for Northern Australia, including:
  • planning for spatial and temporal connectivity;
  • protecting important aquatic refugia in intermittent systems; and
  • conserving genetic diversity which is important for species to be resilient to environmental changes.
• the development of a new decision framework and mathematical tool to identify which conservation management actions to implement where to maximise the persistence of species with the least cost; and
• generated data on species distributions, species responses to threats and costs of management actions to inform the decision framework.

The project has delivered a better understanding of the environmental and evolutionary processes that sustain aquatic biodiversity.  It has improved data, tools and approaches for effective and efficient freshwater conservation prioritization. This has included:

• An assessment of fish biodiversity & risks in Kakadu National Park;
• geodatabases and maps of aquatic ecosystem attributes and threats;
• mitochondrial DNA (mtDNA) sequence database for freshwater fish;
• predictive models of freshwater species distributions;
• estimates of ecological responses of aquatic assets to conservation management actions.
• new approaches to improve planning for freshwater ecosystems (incorporating ecological and evolutionary processes); and
• spatial prioritization tool for multi-action planning.

Field work was undertaken within Kakadu National Park and in the Daly River catchment in the Northern Territory.  Models of freshwater fish species distributions were prepared for across Northern Australia.  The tools and framework developed are relevant across northern Australia.