Case study -Upokorehe get 'hands on' with mangroves

Upokorehe get 'hands on' with mangroves

The Upokorehe hapu gained resource consent in 2011 to remove outlying mangroves from the Ohiwa Harbour. During the summer of 2011/2012, Upokorehe hapu volunteers worked hard to remove just under four hectares (by hand!) of mangroves from the Kutarere area.

Upokorehe spokesperson Maui Manuel said: "The work was challenging in the heat and soft mud, so our team worked very hard for several hours, and then had a great social time and barbeque."

Upokorehe is the only group in the Ohiwa Harbour to have a resource consent (a permit from the Regional Council) to remove mangroves. Through the recent 'hands on' experience, the group is now expert in how best to do this work. An important feature of the mangrove removal project is recognition of the value of mangrove habitat (particularly for the rare banded rail bird), so not all mangroves can be removed. Instead, there are defined areas where removal is desirable. The muddy mangrove habitat is generally less rich in desirable bird and shellfish species than the sandy substrate areas of the Harbour.

Considerable research was carried out into the ecology and spread of the mangroves. In recent years, mangrove populations have increased enormously and scientists agreed that if left unchecked, mangroves could potentially cover 95 percent of the Harbour. Click here for more information about the sediment and mangrove plan. 

During the mangrove removal project, sediment particle size is monitored.The hope is that removing mangroves will help fine mud particles flush out of the Harbour, leaving coarser material. This provides a better home for the native worms and invertebrates that wading birds and fish live on, and for pipi and cockles. Photo points are also being established at each removal site, with photos are taken before and after each working bee to record visual changes over time.

The project is an example of iwi demonstrating their kaitiakitanga of the Harbour by leading with action for the benefit of the Harbour.

Removing mangroves outside the conditions of the resource consent is not allowed. However, if you are keen to help out with this work, please contact Tim Senior at the Bay of Plenty Regional Council on the contact details below.