Check out this HUGE carp what was fished out of the Swan River!
Can we start a debate?
Does the presence of carp or goldfish in rivers indicate they have out-competed native aquatic animals and are destroying the environment? Or does it mean that there was significant environmental degradation (increased salinity, decreased water volume and flow, increased effluent, herbicides, fertilisers) that they are the only ones that can survive/flourish in this type of habitat?
Another question we could ask is,
- are there
, or
- what are
the beneficial impacts of having these fishes in our waterways? Perhaps the suppression of other invasive creatures such as the mosquito fish and mosquitoes? Carp and goldfish are prey species and so they might provide food for other aquatic animals. The article mentions they eat algae and so could it be that they may be playing a role in keeping algae in check?
The concerns about feral fish and the way its being addressed is one thing.
Perhaps the biggest issue is the slavish devotion of biologists to von Bettalanffy growth models developed for European potato growth in Europe in 1928 to explain fish growth.
Von Bettalanffy growth models are easy which explains why they are used but they simply don’t explain this observation. Perhaps W A biologists could look at the growth models that explain this.
If they moved to this era it would only explain the maths but not the problem.
Some partial solutions are already out there for the Swan but they should be considered.
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