Report: TR 2008/24

Author: Bernard Brown Associates Ltd

Abstract

Environment Waikato is considering a plan change to the Regional Coastal Plan that will enable fish farming and other new types of aquaculture in the existing Aquaculture Management Areas (AMA) located offshore from Wilson Bay, and the Coromandel Peninsula.

Bernard Brown Associates has been engaged to undertake a Natural Character and Visual Impact Assessment of the proposed fish farming aquaculture activities. As a baseline assessment, the study is required to compare full development of mussel farming aquaculture in the existing AMAs with potential fish farming activities. The study focuses on the greatest concentration of marine farms on the Peninsula’s west coast from Wilson Bay to Amodeo Bay.

Existing mussel farming activities in the Waikawau/Wilson Bay coastal environment are located in Area A of the Wilson Bay Marine Farming Zone sited 1.5 kilometre off shore. The mussel farm activities generate visual effects caused by buoys, barges and navigational lighting. The buoys (the actual farms) are generally innocuous and their presence in the CMA is signified by the barges working the farms.

Existing mussel farm activities in the Coromandel/Motukawao coastal environment are randomly located throughout the CMA often in close proximity to the mainland and islands shoreline. The Coromandel sub unit is in a delicate balance with respect to any additional mussel farming activities being developed in this area.

There are two key variables that affect the ability of the marine environment to visually absorb mussel farming activities. These include:

a) the scale of the receiving coastal environment and the degree of visual interest in the view.

b) elevation and distance viewed.

The vast scale of the Waikawau/Wilson Bay coastal environment provides high visual absorption capability, sufficient to accommodate full development of mussel farming expanding into Area B of the Wilson Bay Zone without causing adverse effects on natural character values.

In the Coromandel coastal sub unit additional mussel farms would have a significant visual impact and should not be allowed unless those effects can be remedied or mitigated. A precautionary approach is recommended for this area.

Based on a model fish farm using circular sea cages, fish farming will have increased visual effects compared to mussel farming activities. This is primarily due to their characteristic vertical structural elements. Viewing distance (for example 5km offshore) is considered a key visual mitigation measure. When considering the location of fish farming in the Wilson Bay Zone, Area B is the preferred location for large scale (50 hectares or more) fish farming activities from a visual impact perspective

Fish farming activities would assimilate best when seen in conjunction with existing mussel farming activities. Established mussel farming activities would form the foreground, provide context and mitigate the effect of additional fish farm structures.

To maintain and protect the natural character values of the coastal environment fish farming activities should avoid high visual audience areas where close views are gained.

Natural Character and Visual Impact Assessment of Potential Finfish Farming Development [PDF, 371 KB]