Manly's dam shame


Manly Dam and the surrounding catchment area is

Environmental Science students will assess the delicate ecology of Manly Dam and the surrounding catchment area, when an innovative course involving the local community runs again this year.

The freshwater ecology course designed by Senior Lecturer Dr Richard Lim draws on ideas developed by Senior Technical Officer Mr Peter Jones about community participation in environmental research and education.

Manly Dam was chosen for the course because it is one of the few accessible freshwater bodies in Sydney. Like most areas of remnant bushland, it is also under increasing pressure from recreational use and nearby residential and industrial areas. It has been the subject of a tussle between community members who wanted it preserved, and a residential developer who was recently given the green light for a 41-block development on the northern fringe of the reserve.

It is within the context of this political and community fray that students will be conducting their research. Dr Lim says the subject will prepare students to deal with similar situations in a work environment. "Generally students tend to deal with environmental issues with little appreciation of community and political ramifications. This subject helps them realise that there are many stakeholders involved in the management of the environment."

An open day for the subject will be held at the Dam later this year, and members of the community will be invited to submit suggested topics for the students to research. The students then choose their preferred topics from among those submitted and, at the end of the subject, they will present their research findings to the local community in a public seminar.

When the subject was run for the first time last year, students looked at contaminants from streams and stormwater drains flowing into the dam, macro-invertebrates in the creeks, and the impact on the catchment of the adjoining Wakehurst Golf Course. One group of students examined a unique population of a rare fish, the climbing galaxid (Galaxias brevipinnis). The population in the catchment waters is one of the most northerly populations in Australia, and the only land-locked group in Sydney.

The students counted between 30 and 40 fish in the catchment and suggested that a breeding program for the population might be one way of ensuring its survival.

However, Mr Jones says there is "no point in restocking" if the overall health of the Dam remains precarious. "To really get the numbers up again you have to look at the habitat quality and how the catchment supports that population. If you do everything right in the catchment then the numbers are naturally going to go up," he said.

In spite of the intense community interest in the area, Mr Jones says he's not optimistic about the future health of the catchment. "It is sitting right on the edge of collapse. It's like a patient who has all these risk factors for a heart attack. It is a multi-dimensional problem and to solve it is not easy. It needs a catchment management approach and a sustainability commitment to bring it back on track."