Header: The native Crimson-spotted Rainbow fish are still reasonably common in many SEQ waterways. This pair are from Christmas Creek in the Logan River catchment. Photo by Gunther Schmida.

There are not many native freshwater fish on the menu these days. Not long ago this was quite different with Brisbane River Cod sustaining generations of indigenous people and early settlers. As with most wildlife, the abundance and diversity of native freshwater fish has plummeted over recent decades. This has not gone unnoticed, especially to fish researchers such as Leo Lee who I was delighted to meet at a recent thank you breakfast hosted by Brisbane City Council for Brisbane Land for Wildlife members.

Leo’s focus is fish genetics, and it was a steep learning curve for me, but the following take home messages are hopefully useful for all landholders:

  1. Restore creek banks.
  2. Improve water quality in creeks.
  3. Don’t translocate (move) fish.
  4. Survey your creeks for fish.

Healthier creeks will have healthier populations of fish, and will also have more native fish and more native fish species.

Translocating wild fish and releasing captive fish pose major problems for native fish. Many people think they are doing the right thing by releasing captive native fish into their local creek, or as Leo calls it the“Free Willy Syndrome”, but this intended act of kindness can be quite detrimental.

Releasing aquarium fish, even native species, can introduce diseases into healthy native fish populations. In addition, translocating native fish, from one stream to another, can reduce the overall genetics potentially resulting in populations that are less able to cope with droughts, disease and rising climatic temperatures. So, in summary, never move wild fish or release captive fish.

Surveying your creek for fish is a great way to learn more about local wildlife. Leo offered some excellent tips on how to survey fish, and I will share these in the next newsletter edition (sorry, I ran out of room here). It is important to know that most native fish are cryptic, that is, they are fishy and can be tricky to catch. On the other hand, pest sh such as mosquito fish, swordtails and guppies can be colourful, abundant and easy to catch. So just because you don’t catch native fish, it doesn’t mean that they are not present.

Australian freshwater fish are unique as our continent has the highest variation of water ow in the world, so please keep in mind these four key points to help our fish.

Article by Deborah Metters

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