We have now established a successful breeding population of Western Pygmy Perch in an artificial pond located in our environmental centre. We also have back-up populations in aquariums located within science classrooms; these fish have been used to stock both our pond in the wetlands, and Bunbury City waterways.
The pond in the wetlands, Koopoolang, is not a controlled environment; the fish are exposed to predators and seasonal water quality changes not present in the artificial pond. It has been necessary to rehabilitate this area to improve conditions for wetland creatures and especially the native fish.
The following tasks have been completed to develop a pond in the school wetlands that now has a breeding population of Western Pygmy Perch:
- a pipeline has been installed to maintain water levels throughout summer
- stabilisation of banks with retaining walls and paths
- re-vegetation of the banks and around the water line
- installation of two concrete troughs below ground level to hold water if there is a problem with maintaining the water supply over the summer
- introduction of native, submerged aquatic plants
- improvement of filter receiving school runoff water
Western Pygmy Perch have been sampled monthly from this pond for the last 15 months. Samples include both juvenile and adult fish, indicating that the fish are breeding. A healthy variety of macro invertebrates have also been recorded. Both the submerged and emerged plants are growing well, as are the surrounding vegetation. Koopoolang Pond is becoming an established natural breeding habitat for the Western Pygmy Perch
Over the last three years, approximately one hundred Western Pygmy Perch have been released into Bunbury City waterways. The release sites were selected because they met the following requirements:
- water is present throughout summer and autumn
- low level of nutrients
- pH is within a suitable range from 6.5 to 9
- low levels of conductivity and salinity
- aquatic plants and marginal sedges are present to provide suitable attachment for Western Pygmy Perch eggs
- reasonable cover of surrounding native vegetation
- presence of other native fauna such as tadpoles, frogs, goby fish, turtles suitable and varied food source is available
Six sites were selected. Horse-Shoe Lake , St Mark’s Pond, Big Swamp , Five Mile Brook, West Street Sump, and Dodson Street Lake met the requirements; at five of these sites, signs have been erected to inform the public about the project.
Dodson Street Lake is the only location where Western Pygmy Perch have been recaptured so far – their presence here is encouraging.
Western Minnow have been difficult to keep and breed in aquariums, and are better suited to the larger open waters. Koopoolang Pond will be more suited to establishing a breeding population in 2007 and 2008; if this is successful, then more Western Minnow will be released into Bunbury City waterways as the population grows.