Techniques trialled to clean up Onehunga Bay
19 September 2005
Techniques trialled to clean up Onehunga Bay lagoon
A project is currently underway to find the best method of reducing the amount of sea lettuce in the Onehunga Bay lagoon.
Auckland City hopes this will help make it a more appealing recreational playground and over the forthcoming summer months will be trialling various techniques to discourage the growth of weed in the lagoon.
These trials will include tidal flushing so that the water from the harbour flows in and out regularly with the tide, and occasional flushing, for example at night time.
It is important that these possible solutions are tested during summer, when growing conditions for the sea lettuce are most favourable.
“Auckland City wants the lagoon to be an appealing recreational space for people to use and enjoy,” says Dawn Bardsley, parks officer.
“We are hopeful that summer activities on the water will still be able to take place. However, some of the council’s testing initiatives may mean lagoon users need to make minor changes to some bookings,” says Ms Bardsley.
It is important that people make bookings to use the lagoon well in advance of their intended events. The council will inform users at least one week prior if the tide is unable to be contained for specific events.
The council is asking dog owners to be vigilant when walking dogs in the surrounding area and ensure that all dog droppings are removed. Dog faeces seeping into the lagoon following rainfall can contribute to the growth of the weed.
Dawn Bardsley says the sea lettuce, Ulva, a macrophyte algae, is commonly found in saltwater lakes, lagoons and harbours around New Zealand. It is high in nutrients and makes an excellent garden fertiliser so the public are welcome to collect it from the shoreline for their gardens.
A letter will be sent to those who live near Onehunga Bay lagoon to inform them of the project.