Proposed Coromandel Finfish Marine Farming Zone - Ministry of ...

PROPOSED COROMANDEL FINFISH MARINE FARMING ZONE
REPORT OF THE MINISTERIAL ADVISORY PANEL
As such, water flow tends to move north during strong southwest winds and south during strong
northeast winds. Wind direction in the proposed zone is typically southwest and northeast to
southeast. Model simulations suggest that tidal currents flow southwards into the Firth of Thames
below 10 m water depth and northward out of the Firth of Thames at the surface. 3
Environment Waikato advises that it is currently developing a hydrodynamic model for the Firth of
Thames and southeast Hauraki Gulf (and will include the proposed zone). This model will better
inform the effects of the proposed fish farming activities on the region’s coastal environment, and
will assist the Aquaculture Unit, Environment Waikato, and the aquaculture industry to develop an
appropriate management programme to mitigate marine farming effects (including the proposed
finfish farming activities).
The long axis of the zone is located across these currents, and is largely sheltered from oceanic
swells by Coromandel Peninsula and benefits from some shelter from Waiheke and Ponui islands
to the west. Waves within this region are generally limited to around 0.5 to 0.6 m high (with wave
periods between 3 and 5 seconds); however, larger waves are experienced during storm events.
Several submitters stated that the proposed zone experiences 3 to 4 m high swells particularly
when northeast conditions have set in. NIWA advises that the nature of wave action within the
region means that any finfish farm would typically use 20 to 50 m diameter plastic circle cages
that are best suited for the local oceanographic conditions.
To ascertain the nature of potential environmental effects associated with the proposed Coromandel
Marine Farming Zone, the Aquaculture Unit commissioned NIWA (prior to constitution of the
Panel) to conduct an assessment of relevant production and ecological considerations of the
proposal, 4 as well as the potential cumulative effects associated with Coromandel and Wilsons
Bay fish farming. 5
The NIWA reports have been independently peer reviewed by the Cawthron Institute and the
Ministry’s Aquatic Environment Working Group. The Aquaculture Unit also commissioned the
New Zealand Institute of Economic Research (NZIER) to provide information on the potential
economic impacts of the proposal.
A number of submissions confirmed the proposed zone provides a good site for sea-cage finfish
farming, as it is situated in a deep, well-flushed area with tidal flow, and sufficiently away from
shore to prevent any visual impacts. The Panel considers the proposed zone is a suitable site for
the scale of farming of hapuku and/or kingfish as outlined in the proposal.
3 Giles, 2011
4 Zeldis et.al., 2010
5 Broekhuizen, 2011
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The Aquaculture Unit is a business unit of the Ministry of Fisheries