One of the most beautiful features of Centennial Parklands is undoubtedly its ponds. However, beneath the surface lurks a pest that is damaging not only to those ponds, but other life living beneath – carp.
European carp (Cyprinus carpio) is a freshwater fish native to Asia. Like many pests in Australia it was intentionally introduced to Australia as an ornamental and aquaculture fish (if only we could have had 20/20 hindsight on that one!).
Today they have spread throughout waterways across south-eastern Australia.
So, what’s the problem with carp?
Carp degrade the water quality of our ponds, is a prolific breeder and reduces the survival chances for native fish.
It increases turbidity (that is the term for the ‘muddiness’ created by stirring up sediment) preventing light penetration into the water. Less light penetration affects plant growth, which is a valuable food source for native fish, and contributes to erosion of the banks of the ponds.
It is also suggested that this turbidity impact may increases the likelihood of algal blooms (by preying on animals that eat algae, stirring up nutrients trapped in bottom sediments, damaging aquatic plants, and reducing plant growth via greater such turbidity). Read about even more impacts here.
A world record!
In 2008 one of our volunteer fishermen, Paul Cooper, caught what was later to be certified as a world record fish in Centennial Park (later certified in 2010).
OK, well what are we doing about this problem?
Fishing is not permitted in Centennial Parklands, except as part of a supervised program. There are numerous activities we undertake to control and reduce the carp levels in Centennial Parklands’ ponds, including:
- A coordinated program of line fishing: using traditional fishing methods, we are selectively removing carp. This is considered more effective than wider-impact activities such as netting, which risks catching native and non-targeted fish and aquatic life. THe program uses purpose-made barbless hooks and all participants undergo a strict induction and are overseen by the Australian National Sports Fishing Association.
- Native bass fish release: through support funding, we have released more than 15,000 native bass fingerlings over the last three years. These Australian bass (Macquaria novemaculeata) predate upon young carp and have shown effective results at reducing the number of juvenile carp in the ponds.
- Research: we are also involved in a Scientific Management Tagging Program, under the auspices of the University of Western Sydney, involving a catch-tag-release approach. Tagging allows the monitoring of individual fish and the documentation of distribution, abundance and growth. The data gathered helps is to understand how to best manage the population into the future.
- Therapy: one of the nicest behind-the-scenes stories is the Fishing 4 Therapy program, that combines pest eradication with providing opportunities for people with disabilities to experience a therapeutic activity. And it’s really reaping rewards – read more here.
How else are we improving the ponds?
Removal of the European carp is just one way we are improving the water quality in the Parklands’ pond system. Other activities include:
- Planting of native water grasses
- Pond bank restoration / stabilisation
- Installation of gross pollutant traps at the Parklands’ stormwater entry points
We also use this problem for education!
As part of our hands-on community education programs, we regularly run fishing clinics for kids that aim to educate kids on pest management while teaching them a new life skill. Check our What’s On for the next program dates.
Looking after a 360 hectare public parklands is a complex challenge – particularly managing the natural environment. Find out more about our environmental management practices here.