If you look hard enough at the fine print you will find reference to adaptive management in the Murray Darling Basin Plan, but what does adaptive management mean in the real world?
There is growing evidence that the “just add water” approach to the Basin Plan isn’t working, socially, economically and environmentally, which is even greater reason to address the need for multiple measures and an on the ground adaptive approach to the Basin Plan and watering programs.
Without a doubt Europeans have changed this country; what we need to accept is that no amount of policy or water will return it to what it was, nor can we do this or we will quickly run short of food and water for our rapidly growing population.
One of the key problems to returning native fish populations to acceptable levels is the ‘rabbits of the river’, the carp. The introduced species cause untold damage to the river, muddying the water, destroying native plants, and competing with native fish for habitat and food, not to mention preying on them.
Locals will tell you that carp numbers have risen significantly after the 2016 floods, and you need to look no further than fishing competitions throughout NSW and SA for supporting evidence. In a SA carp fishing competition, 16,660 carp were caught in 9 hours (the average over the last 4 years is less than 2000), and the 2017 Wakool fishing competition resulted in only 4 native fish been caught, and thousands of carp. Native fish numbers were well down on recent years.
The most recent science indicates that re-inundation of wetlands in the basin directly after a carp breeding event will significantly increase carp numbers and their ability to maintain high populations. This will result in severe continuing impacts on our native fish stocks, and other aquatic flora and fauna.
Recent reports also state that the carp population in the Lower Lakes is estimated to be 846,000 adult carp, but they have a carrying capacity of 4,195,000. Last year’s floods have created the ideal breeding conditions, thus it could be presumed that there could be up to 4 million carp in the Lower Lakes currently, ready to spawn again if conditions are right.
The graph in this blog clearly shows that flood plain inundation in consecutive years benefits carp and not the native fish population, and research also shows that in-channel flows are most beneficial to native fish.
Three months ago the MDBA put out a press release stating that for the 2017/2018 year it planned to create flows which will build on the flood plain inundation resulting from the 2016 floods. Despite the fact that it has been pointed out that the potential risks with carp breeding could outweigh the benefits it seems that planned floodplain inundation will go ahead.
Surely adaptive management would mean listening to communities and scientists and then adjusting plans accordingly as new information becomes available?