To: Rivers and Catchment Services Group

Waikato Regional Council

Submission on: Proposed Whangamata Mangrove Removal Consent Applications

Name: Royal Forest and Bird Protection Society of New Zealand Inc

Address: Alan Fleming

Royal Forest and Bird Protection Society of New Zealand Inc

PO Box 70 171

TAURANGA 3155

Dear Sir or Madam:

Forest & Bird opposes all of the applications on the following grounds:

1. The activities proposed are contrary to the policies of the NZ Coastal policy Statement 2010.

2. The rate of mangrove spread has slowed to a negligible increase.

3. There are no plans by the Council to lessen sediment coming from the catchment and the 2007Whangamata Harbour Plan failed to address sediment from exotic forestry plantations in the catchment and their contribution to harbour sedimentation. There is no evidence that the controls on soil erosion in the Waikato Regional Plan are lessening the source of sediment into the streams flowing into Whangamata Estuary

4. The application exacerbates the impacts of catchment erosion and climate warming which are prime drivers of mangrove expansion in the Whangamata harbour. It does not adequately acknowledge the role mangroves plays in moderating these impacts on the coastal ecosystem by growing on sediment in estuaries, utilising additional nitrogen from run-off (albeit less in this particular catchment than many others) and regulating rising carbon dioxide concentrations by converting carbon dioxide into biomass and substrate sinks. 2

5. Forest and Bird is concerned that Waikato Regional Council is using ratepayers resources for unjustified mangrove removal but effectively taking no steps to address catchment erosion and associated sedimentation of freshwater and coastal environments.

6. This consent fails to address any changes in the rate of sediment transport into the estuary, whether the Regional Plan is having any effects on lessening sediment moving into the estuary and quantifying whether the rate of accretion of tidal flats is lessening or static.

7. The application relies on data on mangrove removal from Tauranga Harbour, where the hydrodynamics are quite different from Whangamata. In those parts of Tauranga Harbour that have some similarities, monitoring has not shown the flushing effect of fine sediments inferred in the application and A.E.E.

8. The clearance areas proposed in the Moanaanuanu Estuary will have little or no effect on flood abatement or sediment transport. The causeway itself is the major impediment to flood flows, reducing flow velocity creating conditions where sediment starts dropping out of river flows. This sediment is then deposited on the mud flats above the causeway (with or without mangroves) and then redistributed around that part of the harbour.

9. The illegal removal of mangroves from an area adjacent to the Moanaanuanu causeway has done nothing to change the muddy nature of the sediment there. Primarily as the causeway is the main barrier to flood flows, reducing river flows leading to sediment deposition and increased mangrove habitat.

10. Mangrove clearance on a number of the areas up the Moanaanuanu Estuary are likely to mobilise silt moving down the river and into the marina. Areas E1, E2 and D appear to trap sediment that would otherwise go downstream and some depositing in the marina. This would create on-going increased maintenance.

11. There has been no credible monitoring evidence to verify either way whether any of the objectives of the previous mangrove clearance consents have been achieved (greater biological diversity, improved harbour flushing and reversion to a cleaner harbour). The only credible changes have been aesthetic and social, where some people feel better with mangroves removed. There is a lack of information relating to “numerous examples of estuary life has recovered post mangrove removal ...” (see 4 - The Issue in the A.E.E.).

12. Most of the sites proposed for clearance fail to meet the ‘benefits’ list apart from providing access for locals to mud flats.

13. The application relies on the Harbourcare A.E.E., yet much of the information in the AEE was not accepted as credible by the Environment Court 3

14. The significantly different hydrodynamics of clearance areas in Tauranga Harbour cannot be confidently applied to Whangamata Harbour.

15. The application seeks 30 and then 35 ha of clearance, yet the need may be current, but appears to be unlikely beyond 5 years, when most of the work proposed will be completed.

16. In Forest and Bird’s previous submission re mangrove removal within the Whangamata harbour (mulching machine application 2010), we requested information from the Waikato Regional Council of documented research which shows that mangroves display sea grass. There is no information on this matter in the current application or A.E.E.

17. It is unclear as to who will accept the ongoing task and costs of mangrove removal, i.e. seedling removal. This role could potentially continue indefinitely.

18. There is inadequate information with regard to mitigation of adverse effects.

19. There is no detail with regard to:

 the scientific design of monitoring

 size of trial areas associated with other mangrove removal methods outside of the 1 ha (racking or plucking) trial area.

 Who will undertake the monitoring?

20. It appears that the 1 ha pilot trial (racking or plucking) will occur concurrently with other clearance methods being implemented. This is counter intuitive as adverse effects associated with the larger clearance methodologies could not be avoided by implementing a potentially better method as undertaken in the trial area?

21. The A.E.E. talks favourably of the recent cutting head trials in Tauranga but fails to mention that the Bay of Plenty Regional Council did not adopt this methodology as the cost was significantly greater than using the mangrove mulcher.

Yours Sincerely

Alan Fleming Central North Island Field Officer Royal Forest and Bird Protection Society of New Zealand