This chapter relates to marine farming throughout the coastal marine area of the Waikato Regional Council.1
The cultivation of marine species takes various forms, including suspended culture from rafts, longlines, inter-tidal racks and bottom sea culture. New forms of technology are continually being explored to increase farming efficiency and capability and to reduce environmental impacts. At present, the two major types of marine farming within the Waikato Region are conventional mussel longlines and inter-tidal oyster rack farms. The majority of marine farms are found off the West Coast of the Coromandel Peninsula, offshore between Wilson Bay and Papaaroha, because of the favourable climate and water temperatures, high water quality, nutrient availability and a number of sheltered areas.
Conventional longline mussel farms usually require permanent and relatively deep water in order to achieve optimum growth, while oyster farms are generally established within inter-tidal areas on conventional rack structures. While the majority of longlines are currently used for growing mussels, technology improvements have meant that different marine species, e.g. oysters, scallops, seaweed and sponges can also be grown on the same longline structures, with little change in the environmental effects produced. The RCP needs to be sufficiently flexible in order to accommodate new farming technology, while ensuring the adverse effects of all types of marine farming are adequately addressed.
Marine farming is an industry of increasing social and economic importance, and can be a sustainable and efficient use of the CMA if it is appropriately located and managed. Some of the benefits of marine farming include:
- economic and social benefits, including direct and indirect employment opportunities.
- reduction of the pressure on natural fish and shellfish stocks by providing an important alternative source of fish and shellfish.
- enhancement of recreational fishing.
- providing a focus of interest for tourists.
- providing a good indicator of the quality of coastal waters because of requirements for clean, high quality water.
Many parts of the CMA are highly valued for their natural character, landscape, amenity, ecological, cultural and recreational values. Marine farming can conflict with other uses and values and can have adverse effects on the CMA, although many of these effects can be avoided, remedied or mitigated by appropriate site selection, choice of marine farming operation and farm management practices. Adverse effects may include:
- alteration of natural coastal processes, particularly sediment transport processes from marine farm structures, and nutrient cycling processes.
- deposition of shell and waste material beneath farms.
- disposal of non-biodegradable material into the CMA, including plastic floats, buoys, ties and ropes.
- degradation of natural character, landscape and amenity values.
- disturbance to the foreshore and seabed.
- adverse effects on ecology and marine habitat, including the smothering or displacement of marine species living directly beneath farms and the introduction of organisms with biosecurity or biodiversity risks through marine farming activities.
- restrictions on public access.
- exclusion of other uses from marine farming areas.
- conflicts with recreational uses and boat mooring areas.
- adverse effects on navigation safety.
- impacts on onshore facilities (e.g. landing facilities, roads).
- high levels of noise associated with marine farming operations.
- adverse effects on water quality, particularly if artificial food, antibiotics or high levels of organic waste are added to the water, or if shellfish are washed down or cleaned in the CMA.
- adverse effects on areas of significance to tangata whenua.
Tikapa Moana (Hauraki Gulf) is a taonga, an ecosystem of great importance to the Hauraki people of today, of the past and for future generations. It is a productive environment, sustaining abundant customary fisheries. Marine farming may adversely affect the relationship of tangata whenua with their ancestral taonga, particularly by restricting access to and use of traditional coastal resources, such as customary values and interests to the foreshore and seabed, customary fisheries and fisheries management.
Tangata whenua have lodged applications with the Maori Land Court for recognition of their customary title to the foreshore and seabed around the Coromandel Peninsula, including the greater part of the Firth of Thames. There are also Waitangi Tribunal claims for land including parts of the seabed and foreshore around the Coromandel Peninsula. These applications/claims seek legal recognition of tangata whenua customary ownership rights to areas of the foreshore and seabed. Customary ownership and its importance to tangata whenua is part of cultural well-being. Recognising the characteristics of Tikapa Moana that have special value to tangata whenua needs to be recognised in relation to Part II of the RMA.
Most of the western Coromandel Peninsula coastline has been closed to new marine farm applications since the early 1980s by gazette notices issued under the Marine Farming Act 1971. Therefore, there are currently a limited number of marine farms established along this coast. However, demand for space for new marine farming development is high, particularly offshore from the Wilson Bay area. This trend could potentially continue into the future. The careful allocation and management of space for marine farming will be critical to achieving sustainable management of the natural and physical resources of the CMA.
The NZCPS provides for the use of a precautionary approach to help avoid the effects of activities on the environment where there is a lack of understanding about coastal processes and the effects of those activities on coastal processes, particularly where the effects of those activities are unknown or not well understood. There is a limited amount of information available on the cumulative effects of marine farms on marine ecosystems, both over time and within areas subject to a concentration of development. In addition, the environmental effects of large blocks of concentrated marine farm development, e.g. areas of development greater than 50 hectares, particularly in the Firth of Thames semi-enclosed water body, is uncertain.
Most marine farming operations have associated requirements for land-based facilities, e.g. wharf facilities, processing and disposal of waste, transport and communication links (roading, telephone and power), plant and equipment requirements, water supply and wastewater disposal. Approval of these activities where they are located above MHWS, is the responsibility of territorial authorities. Regional councils are responsible for issuing resource consents for marine farming activities below MHWS. In order to achieve integrated management, Environment Waikato and territorial authorities need to adopt a consistent and co-operative approach in dealing with marine farming.
If produce from the marine farm is to be sold for human consumption, a sanitary survey for the proposed farm area needs to be completed by Health Waikato to ensure the water quality meets national marine farming standards.
Marine farming is also affected by land uses above MHWS which can have an adverse effect on coastal water quality and influence the ability of an area to sustain marine farming activities. Health Waikato undertakes regular water quality monitoring within marine farm areas, and can close marine farms down if discharges or heavy rainfall cause a risk to human health through the consumption of shellfish from these areas.
Integration and co-ordination between all agencies with marine farming responsibilities is important in achieving a consistent management approach and in promoting the sustainable management of coastal resources.
Under section 12A of the Resource Management Act 1991 marine farming can only occur within Aquaculture Management Areas (AMAs) that have been approved by the Ministry of Fisheries, and farmers must be listed on the Fish Farmer Register maintained by the Ministry.