LSB Wetland ecology and restoration

This page is about the Little Shoal Bay wetland which runs from just above the Glade Place-Valley Road bridge down to the tunnel which flows to Little Shoal Bay. It is said to be the second largest raupo wetland on the North Shore. But it also contains some fascinating areas of Carex wetland with mixed species.

The LSB wetland has been a major project for the Le Roys Bush group as it has been infested for a long while by crack willow and pampas grass. Thanks to support from the Auckland Council and the Birkenhead Licencing Trust/Lion Foundation, these two pest plants are almost under control. However as the willow retreats, many other weeds are emerging and require ongoing attention.

The following photo was taken in November 2011. The stumps seen in the picture are the remnants of the crack willow which had been dominating the wetland for many decades.

Weed species have also been entering the wetland from surrounding properties. In 2009, a major project was undertaken with support from an Auckland Council's EIF grant to eliminate a major sources of pest seeds from wattles and acmena (aka monkey apples) around the south west arm of the wetland. This project also needs annual followup.

Technically the LSB wetland is a swamp. However, many people prefer to call it a wetland - to avoid the negative connotations of the word swamp.

According to experts, the LSB wetland plays a vital role in preventing a whole range of contaminants entering the Waitemata Harbour. In addition to this benefit, the wetland is also home to a wide range of bird species, geckoes and native fish. Unfortunately the lower wetland has also been overtaken by the imported pest fish Gambusia (aka Mosquito Fish). A scientist at Northcote College has been studying the interaction of gambusia with the kokopu and other native fish. He finds that kokopu/whitebait are getting through the gambusia with minimal evidence of being attacked by gambusia at this stage. The research is ongoing with no firm conclusions at this stage.

In 2008, the Auckland Council funded a study of the LSB wetland. This served the basis for weed control and wetland management for several years. In November 2011, a further phase in studying the ecology of the wetland has started. This study will be documented on these pages as it progresses. The study was initiated following a visit from ecologist Chris Ferkins of the Auckland Council. However due to resource constraints this "citizen science" study did not progress. Subsequently raupo is spreading into areas where previously carexes were predominant.

Details of the work undertaken in the wetland in previous years can be found in the attached page Little Shoal Bay and Lower Wetland.

The major progress made in the Little Shoal Bay Wetland would not have been possible without the generous grants from:

The Auckland Council (EIF and CEF grants each year from 2008 as well as invaluable support from Council officers) and from the Birkenhead Licencing Trust/Lion Foundation.

Footnote: as at 2016 tidal surges sees raupo at the bottom end of the wetland killed by salination. Also the Northotel College fish monitoring team reports a major drop in the Gambusia population.