Achieving impact

Lungfish Habitat Rehabilitation

Lungfish Habitat Rehabilitation

 

The long-term survival of the prehistoric Australian lungfish is a step closer.


VIDEO | Check out the great short video on lungfish at the end of this page!

Lungfish in a tankWork to protect the oldest freshwater fish in the country also helps the quality of a major source of drinking water.

The long-term survival of the prehistoric Australian lungfish is a step closer after a clever South East Queensland project unearthed some super innovative techniques to protect their habitat, which are crucial to their ability to breed.

Stable populations of Australian lungfish are only found in three river systems in the world, so protecting their habitat in those rivers is critical to their survival.

The project found clever workarounds to the long-running difficulties of trying to re-establish submerged aquatic plants.

The project is focused on:

  • Restoring lungfish breeding habitats in the Brisbane River.
  • Improving river health and water quality.
  • Increasing knowledge of riparian restoration and lungfish habitat in the Brisbane River system. 

The project is being run in the mid-Brisbane area, concentrating on re-establishing submerged aquatic plants in the Brisbane River between Wivenhoe Dam and the Mount Crosby Water Treatment Plant.

The plantings will also improve river health and water quality of Brisbane’s major source of drinking water.

What we did

Mid Brisbane Partnerships ProgramLungfish habitat rehabilitation team

The innovative program focused on the tricky task of re-establishing submerged aquatic plants (macrophytes) vital for lungfish breeding that were damaged in the significant floods of 2011 and 2013.

The process of re-establishing the river’s submerged aquatic plants involves:

  • Growing suitable aquatic plants on tiles of biodegradable coir matting in plant nurseries, then transplanting them into the riverbed.
  • To transplant the tiles, the team wades out into knee-deep water, digs a shallow hole in the riverbed, places the tile in the hole, and secures it to the riverbed using rocks and stakes. This is then covered by a layer of sand and rocks.
  • The stakes are made from corn starch which breaks down after a few years.
  • The tiles must be planted in shallow water (less than one metre), as the macrophytes need sunlight to grow, and these areas of shallow gently flowing water are the ideal conditions for lungfish to lay eggs once the macrophytes are established.

The program aimed at planting over 100 square meters of macrophytes in total, to grow and expand to new areas of the river over time.

Measuring success

  • As a result of the program, there has been an increase in knowledge of macrophyte restoration techniques and lungfish habitat status.
  • This information can be used to respond quickly if a large flood event causes similar damage in the future, as well as assist future projects in other locations where Australian lungfish are found.
  • Griffith University is conducting research to evaluate the effects of different water depths, river speed, and riverbed material on the success of the planting program.
  • Healthy Land & Water and Seqwater plan to publish the findings from the program to share the information with counterparts working on riparian restoration and lungfish projects in two other locations where Australian lungfish are found, the Mary and Burnett river systems.

Why this project is important

The Australian lungfish is a prehistoric species that first appeared in the fossil record 380 million years ago, well before dinosaurs.

The Australian lungfish is the oldest known living vertebrate, remaining unchanged from its current form for over 100 million years, and is listed as a vulnerable species under the Commonwealth Environment Protection and Biodiversity Conservation (EPBC) Act 1999.

Several factors are putting pressure on lungfish populations, including loss of breeding habitat, barriers that block access to or inundate breeding habitats, egg predation by invasive fish, and extreme weather conditions.

While the numbers of Australian lungfish in the Brisbane River remain good, their breeding opportunities have been impacted by significant floods. The aquatic plants they lay their eggs in were ripped out of large areas of the riverbed and have not recovered.

Surveys conducted by Seqwater have confirmed very few juvenile lungfish are found in the river and without intervention, the reduced breeding opportunities may start to affect the population in the Brisbane River.

 

Project snapshot

Project name: Lungfish Habitat Rehabilitation program
Project manager: Mark Waud and Samille Loch-Wilkinson, Healthy Land & Water
Catchment: South East Queensland
Timing: 2020 – 2022 (Completed)
Budget: $60,000
Partnerships: This habitat rehabilitation program forms part of a broader strategy that Seqwater has developed to ensure the survival of the Australian lungfish in South East Queensland rivers. Other key project collaborators include Griffith University and the Australian New Guinea Fish Association (ANGFA).
Articles:

 

What's next

There is huge potential to build on the successful work. The project team has identified that if more funding was secured for this project, the next stage would be to establish more sites in the Brisbane River as well as the tributaries, including more nursery sites to sustain the additional plantings. This would build the resilience of the system making it more robust and likely to survive an extreme disaster-scale flood.

Project collaborators

Funding has ended for this project. This habitat rehabilitation program formed part of a broader strategy that Seqwater has developed to ensure the survival of the Australian lungfish in South East Queensland rivers.

Other key project collaborators include Griffith University and the Australian New Guinea Fish Association (ANGFA).

Watch

 Check out this great episode from Back from the Brink on the work to protect this incredible creature here: