Ducks in the Lily Pond
In recent weeks, ducks at the Claude Abel Reserve in Garden Road (Lily Pond) have been showing signs of Avian Botulism. Now it is confirmed that there are water quality issues in the Pond where a number of the dead ducks have been removed.
Water samples have recently been taken and the tests show that the oxygen levels in the Pond are extremely low.
Dissolved Oxygen levels were 4.2 mg / L and 46 % oxygen saturation with the water temperature being 21 degrees.
In comparison – Westgate pond (24 Westgate Rd) 14/02/2007 was 7.1 mg / L and 83% with the water temperature being 23 degrees.
Rush Creek (11 Westgate) 14/02/2007 was 7.0 mg / L and 85% with the water temperature being 20.5 degrees.
In April 2008, invasive water lillies were removed from the Pond and regrowth treated. It has now been recommended by the Council’s Stormwater Quality team and their experts that plants in the Pond are not sprayed and left in the pond to breakdown as this adds to the Pond’s organic load and uses up oxygen. Although spraying of water lillies has not occurred since March 2010, alternatives will be considered for any future waterlily removal.
Even though the winter season is approaching and conditions will naturally improve, intervention is recommended with the mechanical aeration of the Pond. This will involve the establishment of a permanent pump that will operate at various times during the day to pump oxygen into the Pond’s water. Costings are being sourced for this work.
There are also some illegal discharges into the Pond which have not helped and this is being followed up. There are also a large number of Carp in the pond and is another issue Parks will need to consider. (UPDATE – these were found to be not koi carp but goldfish).
There is no Avian Botulism in the Piha Lagoon and Aqualab, the Council’s testers, are also not aware of any at the lagoon.
The Council is investigating what other options Council may be able to use rather than using a pump system to input oxygen into the pond but it appears the pump will be needed to manage the low oxygen levels. This will be communicated to the Piha community and implemented once Council determines the best approach.
Posted 15 March 201; Updated 30 March 2012