There is a range of activities utilising marine resources that might be developed by Mäori for economic benefit. The potential for these activities in Tai Tokerau, and issues related to the sustainability of the resources on which they are based, are discussed below. This discussion relates to marine resources in Tai Tokerau in general. For details about potential opportunities for development of marine resources in specific areas, refer to the regional reports that were provided to each iwi involved in the study (i.e. Jeffs 1995, Forer et al . 1996, Forer et al . 1997a, Forer et al . 1997b, Hay 1998, Hay 1999, and Hay 2000).
The following discussion presents ideas about ways in which marine resources could be developed based on the physical and ecological characteristics if the region. Whether or not they should be developed in these ways involves consideration of a wider set of issues, including the balancing of economic issues with social and cultural values. We also note that at an enterprise level, the commercial feasibility of the utilisation of these resources needs to be carefully considered at a level of detail that is beyond the scope of the present discussion.
Tourism is one of New Zealand's largest export earners, contributing approximately 16 per cent of the nation's export earnings (Ward et al. 2002). Current visitor numbers of 1.8 million per annum are projected to increase to 2.5 million in 2006 (Tourism Strategy Group 2001). Tai Tokerau is close to Auckland, one of the principal tourist gateways in New Zealand, and many tourists travel through at least part of the region (Page et al. 1999). The significant population centres of Auckland and Whangarei also provide a domestic tourism market. A large proportion of Tai Tokerau is not currently highly populated, and has retained significant natural values – unpolluted water, isolated coastlines, and geology, flora and fauna of local and international significance. The Tai Tokerau coastline is very scenic, comprising long sandy beaches, picturesque coves, spectacular rocky shores, and attractive harbours. This makes it ideal for the ‘NEAT' tourism sector - n ature, e co- and a dventure t ourism (Buckley 2000), which relies heavily on high quality environmental resources. This sector also includes tourism based on special activities (for example, fishing). These types of tourism are broadly referred to as ‘nature-based tourism'. Valentine (1992) defined nature-based tourism as tourism ‘ primarily concerned with the direct enjoyment of some relatively undisturbed phenomenon of nature '.
The natural resource requirements for nature-based tourism are determined by the characteristics of the tourism type. Thus for example, the resource requirements for eco-tourism may be different from the resource requirements for adventure tourism.
Eco-tourism is the nature-based tourism type for which the type and quality of ecosystems is most important as a necessary resource. Eco-tourism requires the ecology of an area (i.e. the relationships between organisms, and groups of organisms to their environment) to act as an attractant for tourists. Features such as unusual, rare or endangered species or habitats, good examples of unmodified ecosystem types, or conservation activities may be attractive to eco-tourists. Eco-tourism is defined as ‘ nature-based tourism that involves education and interpretation of the natural environment, and is managed to be ecologically sustainable ' (Commonwealth Department of Tourism 1994). It has been suggested that sustainable eco-tourism imposes an ‘ethical overlay' on nature-based tourism that has an educative emphasis (Wight 1993). Eco-tourism encapsulates the following principles – environmental sensitivity, sustainability, educational experiences, and enhancing the natural environment.
Adventure tourism may be defined as ‘ inclusive of an element of risk in the experience, and requiring higher levels of physical exertion and the possible need for specialized skills ' (Weaver 2001). The natural resources necessary for adventure tourism vary with the type of tourism experience. For example, the natural resources required for a diving experience would be different from those of a kayaking experience. In addition, tourism based on specialist activities such as fishing, or watching birds or sea mammals, require not only particular physical environments, but also the predictable presence of inhabitants of the environment.
Figure 8: Watching dolphins, which are commonly present in some areas on the eastern coast of Tai Tokerau, may form part of a tourism venture based on specialist activities.
In addition to the NEAT tourism sector, coastal or marine resources of high scenic quality, such as a series of magnificent views or unusual physical features, may provide the basis of tourism based on sight-seeing. The ‘Hole-in-the-Rock' at Piercy Island (Cape Brett) is one example of the way in which a natural scenic resource in the marine environment of Tai Tokerau has been utilized for the sight-seeing tourism sector.
Because it is potential for sustainable economic development with which we are concerned, issues relating to the sustainability of tourism are relevant. Sustainable tourism has been defined as ‘ tourism that does not threaten the economic, social, cultural or environmental integrity of the tourist destination over the long term ' (Butler 1993). Ecological sustainability in terms of nature-based tourism is a concept that encapsulates the continued or prolonged use of natural resources without degrading the resource. In the strictest sense, sustainable tourism includes not only having sustained use of the natural feature that is the prime attractant, but also ecologically sustainable practices in terms of water supply, waste disposal, greenhouse emissions etc. relating to that tourism activity. This latter definition separates true ‘eco-tourism' from other nature-based tourism ventures.
It is apparent that there is a variety of marine resources in Tai Tokerau that could be utilised in some way for tourism businesses. These include ecotourism ventures based on showing people sites of outstanding significance (such as bird-watching in the Parengarenga Harbour, visiting offshore islands with locally endemic species or rare reptile populations etc.) or taking advantage of the close proximity of a variety of different ecosystems to show visitors a range of different marine habitats and organisms. The area is rich in sites of archaeological and historical significance that could also be incorporated into such tours, and aspects of cultural tourism, such as sharing the principles of kaitiakitanga, could also be included.
There are also many areas within Tai Tokerau where water-based recreational activities can occur. Indeed, there is a seasonally high recreational use of much of the coastline, as visitors from outside the area come to enjoy the swimming, surfing, diving, boating, fishing, camping, picnicking, and walking opportunities that the area offers. There is potential to turn some aspects of these activities into commercial ventures, where such a venture could provide an experience that a visitor might not otherwise be able to access - for example, by providing the visitor with the equipment, expertise, guides, local knowledge, or the companionship of doing something with a group of people.
In some cases, the potential ecological impacts of tourism are restricted by regulation (for example, the Department of Conservation regulations regarding interaction with sea mammals). However, Ward and Beanland (1996) commented that because there is still a lot to learn about the New Zealand environment, it is difficult to anticipate visitor impacts on the environment before they happen. Potential impacts of tourism on marine ecosystems may include pollution, physical disturbance, the introduction of new species, over-fishing (or sample collection), disturbance/noise, and unwanted interaction with wildlife (e.g. fish feeding etc). There is some difficulty in making general statements regarding the ecological suitability of natural resources for tourism with respect to sustainability. Buckley (2001) has succinctly summarised this difficulty ‘ Different activities, under various management regimes, cause different environmental impacts in different ecosystems; and the ecological significance of these impacts differs greatly among ecosystems '. He goes on to suggest that sustainable nature-based tourism should involve deliberate steps to minimise impacts on the environment, through choice of activity, equipment, location and timing, group size, education and training, and operational environmental management (Buckley 2001). Choosing a site for ecologically sustainable tourism involves matching a set of tourism activities with an ecosystem that is robust enough to sustain the likely impacts of the activities without becoming significantly modified over the long term. In some cases the ecology or physical environment at a site may be too fragile to sustain any tourism activity at all. The development of sustainable tourism thus involves not only consideration of the commercial, social and cultural issues, but also careful consideration of tourism activities within the context of the ecosystems in which they are to take place.
Aquaculture is the farming of aquatic species. Marine aquaculture may occur in the sea itself, or in land-based facilities through which seawater is circulated. World-wide, aquaculture is the fastest growing sector of food production (Jeffs 2003). Global seafood production from wild fisheries has remained relatively static since 1989, suggesting that production limits from fisheries have been reached. However, the demand for seafood continues to increase, and is predicted to increase beyond current production levels by a further 55 million tonnes by the year 2025 (Jeffs 2003). It is likely that this demand will be met by increases in aquaculture production.
Aquaculture is currently well-established in Tai Tokerau, which is one of the major oyster farming areas in New Zealand. The main oyster farming areas within Tai Tokerau include the Bay of Islands, and the Whangaroa, Houhora, Parengarenga and Kaipara Harbours, with smaller areas of farms in the Whangarei and Rangaunu Harbours. The farming of Greenshell TM mussels is less widespread in Tai Tokerau than oyster farming, being principally at Aotea (Great Barrier Island), with relatively small areas in the Kaipara Harbour and Houhora Bay. Mäori are currently very significant participants in the oyster farming industry – Te Ohu Kai Moana (Treaty of Waitangi Fisheries Commission) own one of the largest oyster farming/processing companies in New Zealand, and there are a number of smaller whanau-based oyster farming businesses throughout the area, particularly in the far north. In addition, a company owned by two iwi trusts operates a series of oyster farms in the Parengarenga Harbour and an associated seafood processing plant at Awanui. Mäori also participate in the mussel farming industry in Tai Tokerau, particularly in the collection of mussel spat (juvenile mussels) for on-selling to mussel farmers elsewhere in New Zealand.
So is there potential for further development of aquaculture in Tai Tokerau? The commercial feasibility of aquaculture operations depends on having both suitable species to culture (in terms of economic considerations such as marketability, growth rates, food conversion ratios, price of input materials and final product, etc.), and suitable culture areas. The technical requirements for development of aquaculture operations include:
• water of a suitable quality
• space at a suitable site
• source of stock (juveniles, broodstock)
• food supply for stock
• infrastructural support (e.g. access to site (boat access, road access), place for land base if necessary, power, transport facilities etc.)
The specifics of these requirements differ with the aquaculture species and farming method. However, prior to considering individual species in detail, some general observations are pertinent to the potential for the development of aquaculture in Tai Tokerau. Firstly, the high level of wave action on the open western coast of Tai Tokerau means that this area is not likely to be suitable for aquaculture farms residing in the marine environment. Secondly, while other areas of coastline may fit the suitability criteria for farming of various species in the sea, obtaining resource consents (a requirement under the Resource Management Act 1991) to utilise such space on the sea-bed for marine farming may be problematical. The legislation relating to aquaculture is currently in the process of reform, and in late 2001 the Government imposed a 2-year moratorium on the granting of all resource consents relating to marine farming to provide time for the reforms to be completed. (This moratorium has now been extended). In the future it is intended that all new aquaculture development be sited in pre-determined ‘Aquaculture Management Areas' defined by the Regional Councils. This may limit the scope of sites available, both in area and physical characteristics. Adding to the debate surrounding the utilisation of space on the sea-bed is the debate about ownership of the sea-bed. At the time of writing this paper, these issues remain unresolved. Access to space on the sea-bed and security of tenure are critical not only to the expansion of the aquaculture industry, but also its continued existence.
The commercial viability of farming mussels, oysters and salmon in New Zealand is well-established. The potential for sustainable economic development utilising these species in Tai Tokerau, and the potential for aquaculture of new species, are discussed below within the context of the technical requirements for development of aquaculture operations as outlined above.
In New Zealand, Greenshell TM mussels ( Perna canaliculus ) are grown on ropes suspended from back-bones of ‘mussel long-lines' which are kept afloat by plastic buoys. Long-lines are typically 100 metres long, and 20-40 metres apart. Water depths of 5-30 metres, in areas of relatively low wave action, high phytoplankton productivity and oceanic salinity levels, are required for mussel farming. Because they are filter-feeders, mussels can concentrate human pathogens (such as bacteria and viruses) and toxic substances such as heavy metals out of the water in which they live, with the associated implications for public health. Thus high standards of water quality are required in mussel growing areas in order to protect the health of consumers.
Figure 9: Seeding out mussel spat onto a mussel long-line.
The open coast of Tai Tokerau (both the western and eastern coasts) is subject to too much wave action for mussel farming using conventional farming structures, and many of the more protected sites are too shallow. Notwithstanding regulatory issues related to resource access, our study identified some relatively small areas in Tai Tokerau where mussel farming could be established. However, there is currently a trend of increasing utilisation of economies of scale in the New Zealand mussel farming industry and with the exception of areas at Aotea, areas suitable for mussel farming using conventional methods would be of a size and separation where this could be difficult to achieve. Technological advances however, could provide very significant opportunities for mussel farming in Tai Tokerau in the future. The current development of methods of farming mussels in more exposed sites offers the potential for significant expansion of mussel farming on the eastern coast of Tai Tokerau. However, such farms are likely to have higher establishment and servicing costs than conventional farms (Jeffs 2003). Currently both the practical and financial feasibility of such methods have yet to be proven in New Zealand growing conditions.
There is some risk associated with access to juvenile stocks of mussels. Over 85 per cent of the mussel spat (juvenile mussels) for the mussel industry is sourced from drift seaweed washed up on Ninety Mile Beach. This is unpredictable in timing and volume, which makes it difficult for farmers' seeding-out operations, because sometimes there is a very large amount of spat available in a very short time (which makes seeding out on the farms difficult), and in some years the availability of spat significantly limits production. Spat may also be caught on mussel farms in some areas (e.g. Golden Bay and areas in the Marlborough Sounds in the South Island), by setting out artificial materials which are attractive as settlement surfaces for mussel larvae. This source of spat can also be unreliable, resulting in significant spat shortages in some years. The occurrence of mussel spat in the harbours on the western coast of Tai Tokerau presents an opportunity for the establishment of spat-catching ventures to supply the mussel industry with a source of spat that could be delivered to suit the requirements of the farmers. (Such a venture is currently being established by Mäori in the Whangape Harbour, and areas of the Kaipara Harbour would also be suitable for mussel spat-catching). In addition, the feasibility of producing mussel spat in land-based tanks is currently being investigated by two research organisations in conjunction with industry partners (including Mäori-owned businesses). In addition to ensuring a reliable source of spat, this provides the opportunity to selectively breed for desirable characteristics (such as fast growth, good condition etc.). A land-based facility would require access to water of oceanic quality (i.e. clean, high salinity water with low suspended sediment, and a stable temperature), with sufficient flat land close to sea level adjacent to the coast. There are areas on the eastern side of Tai Tokerau where these criteria would be met. Alternatively existing facilities (such as the National Institute for Water and Atmospheric Research Ltd. (NIWA) facilities at Bream Bay, Whangarei) could be utilised through lease or joint venture arrangements. We note however, that the commercial feasibility of breeding mussel spat is currently unknown, and because mussels are a relatively low value species it is likely to be a significant challenge to produce spat in a hatchery within an acceptable cost structure.
Consideration of the impact of resource utilisation on the environment is an important issue in the sustainability of a resource. Studies conducted on the impact of long-line mussel farming indicate that there is an increase in fish numbers, and hence diving birds, in areas around mussel farms. The fish are attracted to the mussels and the bio-fouling on the buoys and lines. Mussel farming also has some visual impact in an area where mussel farms are close to the shore. In areas of high scenic value, this may be an unacceptable environmental impact.
Mussels excrete high levels of ammonia, and this increases the rate of geochemical cycling of nitrogen. Faeces from the mussels increase the organic content of the substrate under the mussel lines, which can result in a slightly anaerobic (i.e. lacking oxygen) sea-bed, and a consequent reduction in species diversity (Burnell 1995). The impact of this is dependent on the water flow through the site of the farm - obviously in a large, densely stocked farm with little current or wave action, the deposition of organic material on the sea-bed will be greater than that in a farm with a more vigorous water movement. Water flow is also significant in determining the carrying capacity of an area. In areas where large areas of mussels are densely farmed, reduction in the amount of phytoplankton in the water can be so significant that it becomes a factor limiting mussel growth.
In New Zealand, Pacific oysters ( Crassostrea gigas ) are most commonly grown on racks in inter-tidal areas (i.e. the areas between low tide and high tide) in sheltered situations. Pacific oysters are tolerant of suspended sediment and variations in salinity levels, and grow well in the phytoplankton-rich waters of estuaries and harbours. As with mussel culture, a high water quality with respect to levels of bacteria, viruses and heavy metals is required for oyster culture, since they also are filter feeders.
Figure 10: Inter-tidal oyster farm.
Oyster farms are generally built so that the racks are about one metre above the sea floor (to avoid problems with a polychaete parasite locally known as ‘mud-worm'), just above the level of the neap low tide. Many of the harbours and estuaries in Tai Tokerau contain areas suitable for oyster farming, but most suitable areas contain established farms. The sustainability of oyster farming is dependent on maintaining an environment suitable for the growth of oysters. Dense stocking of harbours can reduce phytoplankton levels in the water to the extent that growth is reduced, so increasing the number of farms in close proximity to existing farms is not advisable in some areas. While small areas suitable for oyster farming were identified elsewhere, the most significant potential contribution to Mäori economic development would be completion of development of farms for which Resource Consents have been issued in the Parengarenga Harbour, and development of farms in the Kaipara Harbour. Although there are areas suitable for oyster farming in the Kaipara Harbour, the proportion of suitable areas that are fully developed is relatively low compared to other harbours. A significant proportion of established farms in the harbour are used for oyster spat-catching rather than growing oysters through to market size. This is because the shells of oysters that are grown for long periods in the harbour become fouled with the over-catch of the next generation of oyster spat, reducing their marketability. However, oysters fatten well in the Kaipara Harbour compared to many other harbours, and thus the area is suitable for holding market-sized oysters for a period of time (6-8 weeks) to fatten prior to sale. Such areas could also be used to relay oysters from farms where the quality of the water is not suitable for sale for consumption (as is currently the case in the Waikare Inlet in the Bay of Islands) for cleansing prior to sale. As there is a high demand for oysters and production is currently constrained by the limited area available for farms, the utilisation of the areas suitable for farming in the Kaipara Harbour could significantly increase the productivity of the oyster industry.
In addition to farming oysters on inter-tidal racks, there is some development of sub-tidal farming within the industry. This is mostly done on long-lines like those used in mussel farming, sometimes in stacks of trays suspended off the long-line backbone. Very good growth rates are achieved by this method. However, experiments with this farming method near Coromandel indicate that the oysters are subject to significant fouling by other marine organisms. Because of this, oyster farming on long-lines is generally undertaken in conjunction with inter-tidal farming, and oysters are only put on the long-line for short periods of time when they are nearly of market size, or to fatten up for market. However, in the Marlborough Sounds, oysters are farmed on long-lines throughout the growing cycle. Given the problems experienced in the Coromandel area, it is suggested that an oyster farming operation based solely on subtidal long-line farming should be approached with caution and trialled on a pilot scale first.
In areas where there are large numbers of feral oysters, oyster farmers may be able to catch oyster spat (juvenile oysters) on their own farms. However, the most reliable source of oyster spat has until now been the Kaipara Harbour, where specialised spat-catching farms have been established.
The sustainability of oyster farming is dependent on maintaining an environment suitable for the growth of oysters. Dense stocking of harbours can reduce phytoplankton levels in the water to the extent that growth is reduced. Although the technology for breeding Pacific oysters is well established, the New Zealand oyster industry has been slow to take up this technology, partly because of the cost advantage in wild-caught spat. However with a recent research programme on selective breeding of Pacific oysters having been undertaken by Cawthron Institute, Nelson, interest in hatchery-bred spat is being re-kindled. As previously mentioned, there would be suitable sites for land-based hatcheries in Tai Tokerau. However, with two research organisations now interested in producing spat, business issues would need to be carefully examined before such a venture were initiated. Farms that specialise in raising small hatchery-bred spat for on-selling to other farmers may also present opportunities for development.
A study by Forrest (1991) on the impacts of oyster farms on the benthic environment showed that ‘ in comparison with adjacent unfarmed areas, the sediment below farms was less consolidated, had lower shear strength, was finer grained and was enriched with organic matter '. This is to be expected, since oysters filter plankton and suspended sediment out of the water, and these particles become aggregated as oyster faeces or pseudofaeces. The farm structures disturb the water flow, in general increasing the sedimentation rates in the vicinity of farms. The higher organic content of the substrate below the farms impacts on the species composition of the macrofauna, which also becomes more abundant. Forrest (1991) found a disproportionate increase in polychaetes and deposit feeders under marine farms compared to unfarmed sites. (It has been suggested that this results in the observed increase in numbers of flounder close to oyster farms). However, he also found that the environmental impact of the farms extended no more than 30m from the farm (the study was done in the Mahurangi Harbour). As a result of this study, it is suggested that farms built in areas of fine-grained sediment substrata will impact on the environment less than those built in areas of coarse sediments. Other potential impacts include the visual impacts of farm structures, and potential impacts on wading birds (which include the potential effects of disturbance to nesting and feeding areas, along with the positive impact of enhancement of food sources).
Salmon farming is the other aquaculture industry that is well established in New Zealand. In addition, paua (abalone) farming (both for meat and pearls) is an emerging industry. Salmon farming is not recommended in Tai Tokerau because the ambient seawater temperatures are too high – sea-cage farming of Chinook salmon ideally requires water temperatures of less than 18 o C. Similarly, although found throughout New Zealand, paua are more abundant and grow to a larger size in cooler southern waters. While the generally warmer waters of Tai Tokerau may produce faster initial growth rates in paua, they also greatly increase the risk of cultivation stress and diseases (Jeffs 2003). This suggests that if one were choosing a site for paua farming in New Zealand, Tai Tokerau, particularly the northern regions, may not be an optimal choice of site.
There is a range of new species for which the potential for aquaculture is currently under investigation. Among others, these include large fin fish species (such as snapper ( Pagrus auratus ), kingfish ( Seriola lalandi ), and turbot (Colistium nudipinnis )), rock lobster ( Jasus edwardsii ), and sea horses ( Hippocampus abdominalis ) (Jeffs 2003). Other species that may be suitable for culture in Tai Tokerau include the yellow-belly flounder ( Rhombosolea leporina ), and flat oysters ( Ostrea chilensis ). Conditioning of kina ( Evechinus chloroticus ) to produce high quality roe by feeding in land-based tanks may also be possible. The potential for culture of these and other species in Northland has recently been reviewed by Jeffs (2003), with a more in-depth review of the potential for kingfish culture provided by Poortenaar et al. (2003). The physical resources for culture of all these species are available in Tai Tokerau. However, all are characterised by significant technological challenges and (with the exception of kingfish, for which some financial projections based on current information are provided in Poortenaar et al. (2003)) uncertain commercial feasibility. Exploration of these opportunities requires further investment in research and development before commercialisation would be possible.