WHAT ELSE DO MPAs OFFER?

14.4 WHAT ELSE DO MPAs OFFER?

4 Fishing has effects on the marine environment

Apo

other than direct impacts on target species (Kaiser

reserve

and Jennings, Chapter 16, this volume). These include effects on species which interact with the

1 3 5 7 9 11 target species and are thus secondarily affected, Years of protection

and impacts on habitat, where destructive gears such as trawls are used. The latter may have con-

Fig. 14.3 Increase in biomass of large predatory fishes sequences for fish and fisheries if the habitat is [19 species of groupers (Epinephelinae), 11 species

important in recruitment. of snappers (Lutjanidae), 6 species of emperors

MPA management tends to increase abun- (Lethrinidae) and Carangidae] estimated by underwater

visual census in two Philippine MPAs, showing a curvi- dances of site-attached species which have been

linear pattern consistent with likely patterns of recruit- depleted by fishing. Through this MPAs can play a ment and growth: (a) Sumilon MPA and (b) Apo MPA.

role in the conservation of biological diversity, and (Source: from Russ and Alcala 1996, p. 956.)

in creating greater species richness, expressed as the total number of species. Other measures of diversity have been reported in many MPAs

grounds that the accumulation of biomass takes a (e.g. Cole et al. 1990; Jennings et al. 1995). Such long time, but is quickly dissipated (e.g. Bohnsack increases do not invariably occur, and there are a 1994).

number of reasons for this. In the Philippines,

From what has been reviewed above, it can be species richness rose in one MPA (Sumilon), which seen that the siting of MPAs will influence the per- was enforced between bouts of intensive fishing, formance of their ecological and fishery functions. but not in another (Apo) (Russ and Alcala 1998a), With the exception of a few fisheries closures, although differences in the biomass of target existing MPAs have been sited almost exclusively species were significant. In both cases, the princi- in relation to recreational diving and habitat con- pal fishery targets contributed greatly to commu- servation according to criteria which are mostly nity biomass but little to overall numerical

Chapter 14

abundance. As a consequence species richness was

a poor indicator of the presence or absence of fish- ing even though this was intense, albeit somewhat non-selective (Russ and Alcala 1998a). Since most data on abundance of target species in MPAs are derived by visual means, the sample areas are small, and observer presence can affect them (Kulbicki 1998). In reality effects of MPAs on bio- logical diversity are poorly known; for example, species which are rare and those with large home ranges will be undersampled. Given such sampling constraints, use of a phrase such as ‘local extirpa- tion’, in the context of a small-scale fishery, needs to be classed as provisional until the wider distrib- ution of the species is known. The contention that species extinction is comparatively less common in the sea than on the land tends to be upheld (e.g. McKinney 1998), but there are points of vulnera- bility. For example, species of large size with slow growth and low reproductive rates, such as many turtles, large serranids and elasmobranchs, are vul- nerable (Dulvy et al. 2000; Reynolds et al. 2001). Hotspots of endemism are places where MPAs may play a conservation role. Given the mobility of the larger species often involved, lack of knowl- edge of their life histories, and competing uses of marine habitat, mean protection of whole popula- tions is unlikely, while planning for piecemeal in- clusion of vulnerable stages and habitats will be difficult.

The role of MPAs in biodiversity conservation could be increased by species interactions, such as those between predators and prey, and among com- petitors for space. Shifts in community structure have occurred in many intensively exploited systems in the tropics and in temperate waters, and there is much debate about the exact nature and causes of these changes (e.g. Hughes 1994; Christensen 1998; Fogarty and Murawski 1998). Although food webs and models of carbon fluxes are obvious places to look for synoptic overviews of systems (e.g. Pauly et al. 1998; Pauly and Chris- tensen, Chapter 10, this volume), in fact they pro- vide pictures only of how species are trophically linked, and may not be good predictors of change in community structure where processes such as recruitment, control prey organisms rather than

predation (Chapter 14, Volume 1). This may explain why prey fishes are no more abundant in fished sites than in MPAs in the Seychelles (Jennings et al. 1995) and the Philippines (Russ and Alcala 1998a), or grounds in Fiji with very high fishing pressure when the abundance of predators is greatly reduced (Polunin and Jennings 1998). However, there are cases where linkages between species are tighter, and predators may play key- stone roles, such that community effects of fishing may be reversed in MPAs, as for triggerfish (Bali- stidae) feeding on sea urchins in Kenyan lagoonal reefs (McClanahan and Shafir 1990). Other impli- cations of food webs for changes in communities in MPAs are addressed elsewhere (Chapter 14, Volume 1).

Recreational diving is a point of significant growth in tourism and thus a major source of rev- enue of marine origin around the world (e.g. Dixon et al. 1995). Although there seems scarcely to have been any systematic study of the fact, fishes are undoubtedly a major focus of much diving and snorkelling, and in some cases they greatly influ- ence perceptions of the underwater experience (e.g. Andersson 1998; Polunin and Williams 1999). MPAs, where they increase the abundance or size of fishes which are of interest to divers, may therefore help to generate local revenue through increased expenditure on diving, accommodation, entrance fees and other means (e.g. Dixon et al. 1995). Estimates of the market value of the stand- ing stock of fishery target fish in a Belize MPA (Polunin and Roberts 1993), when compared with the direct revenues to MPAs that are intensively used by divers (e.g. Mattson and DeFoor 1985), in- dicate that marine habitat, in this case reef, can be hundreds of times more valuable per unit area to tourism than to capture fisheries. A substantial part of this tourism revenue is unlikely to reach the local communities involved, and is derived from particular dive sites of limited total area. Conversely, fishing is a more extensive activity than most diving, but the value of the reef as source of catch is lower still when the costs of fishing are considered. On balance, recreational diving has to

be a major potential financial benefit to be derived from MPAs. Where this is focused on large or rare

307 species in particular, the implications for enforce- for biodiversity (Auster et al. 1996). Further, in

Marine Protected Areas

ment need to be carefully considered. The evi- large MPAs, bycatches will no longer be discharged dence from reef fishes is that maximum biomass is back into the environment, and any effects this has built up and large fishes are abundant only if there on abundance of scavengers and predators (e.g. is minimal fishing; a small amount of fishing is Hall 1999) will be reversed. likely to lead to rapid decline in biomass (Fig. 14.4) (see also Russ and Alcala 1996).

MPAs have additional value to recreational

divers such as through the presence of fragile hard 14.5 REALITIES, ADVOCACY

corals and gorgonians. These can be destroyed by

AND IMPLEMENTATION

fishing (e.g. Shaffer et al. 1998). In addition, recov-

OF MPAs

ery from the effects of damaging gears such as trawls on benthic organisms and on habitat struc- As in so much environmental literature, there is an ture (e.g. Engel and Kvitek 1998; Thrush et al. inclination in many of the general reviews that 1998; Kaiser et al. 2000) can be expected to occur in have been written about MPAs to list only known MPAs, especially where natural disturbance is advantages of MPAs (e.g. Plan Development Team minor (Jennings and Kaiser 1998). This may have 1990; Ballantine 1991, 1999; Roberts and Polunin significant consequences for fishery species and 1991; Russ et al. 1992; Bohnsack 1993). These can

be read as promotional statements of benefits that can be expected from MPAs generally. Costs and uncertainties are inherent in all MPAs (e.g. Dugan (a) 16 and Davis 1993; Allison et al. 1998) and many of

these are expressed in Table 14.5. Conflict be-

12 tween potential costs and potential benefits can of

10 course be overplayed, but the water being muddied 8

6 is a vast middle ground between advocacy and sci- Biomass (g/m

4 ence, and consequences of unbalanced judgements

2 can be far-reaching, as evinced by the existence of 0 0 50 100

250 many protected areas on land. It is true that scien- Fishing pressure (persons/km reef front)

tific methods of data gathering and inference are (b)

not the best means alone to address urgent de-

30 mands of growing human impacts on the marine

2 ) 25 environment. In developing countries in particu-

20 lar, advocacy for MPAs does not necessarily solve

15 the underlying problems of seemingly hopeless 10 Biomass (g/m

growing social and economic deprivation (e.g. Pol-

5 unin 1990). In developed regions such as the North

250 Sea or the northeast shelf of North America, it is Fishing pressure (persons/km reef front)

hard to see how politicians will legislate for even more draconian measures than those already in

Fig. 14.4 Biomass assessed by underwater visual place and derived from conventional fisheries sci- census of (a) epinepheline groupers (genera Anyperodon,

ence. These measures have led to the extensive Cephalopholis, Epinephelus, Gracila, Plectropomus and

closure of fishing-grounds decided on the basis of Variola ) and (b) all piscivorous fishes >30cm in length

on reefs in 10 Fijian traditional fishing-grounds varying available data and scientific common sense. It is

600-fold in fishing pressure index from very low levels. worth noting that closures have been applied in Error bars are 95% CL. (Source: after Jennings and

areas such as the North Sea where potential bene- Polunin 1996a.)

fits for particular stocks such as plaice and cod

Chapter 14

Table 14.5 Advantages and disadvantages of permanent or long-term MPAs for site-attached fishes, fisheries management, conservation, science and other stakeholder activities.

Advantages/Likelihoods

Disadvantages/Uncertainties

Fisheries Fisheries yield maintained or enhanced through larval dispersal

Benefits may be only long term

Fisheries yield maintained or enhanced through spillover Higher catch rates confined to a small adjacent area Fluctuations in catch potentially reduced

Most of ground closed, yield likely to be reduced Chances of recruitment overfishing reduced by maintained

Fishing effects increased because only part of stock exploited spawning stock

Fisheries management Undisturbed spawning and/or nursery grounds

Unlikely to be useful for migratory species Temptation of fishermen to violate laws reduced

Incentive for deliberate poaching increased Data collection needs of management potentially reduced

More research needed because of uncertainty as to MPA design Surveillance and enforcement simplified

Increased poaching: increased need for surveillance and enforcement Resources potentially available for mariculture and restocking

Potential vulnerability to recruitment failure Conservation

Habitat protected from damaging fishing techniques Use of damaging methods may be increased outside Endangered/vulnerable species protected

Protection unlikely to be for whole life cycle Biodiversity may be increased

Most species unaffected

Science Areas provided for research on unfished systems

Uncertain baselines, pollution uncontrolled Community protected, biodiversity maintained or enhanced

Recruitment and system-level effects (e.g. reversibility) unsure Other stakeholders

Increased diver use Negative impacts of visitor use and tourism development Management concept more easily understood by public

Local resistance to MPA: detailed research needed to justify Areas provided for nature-educational purposes

Costs of interpretive facilities and access Economic benefits through tourism

Failure of some to benefit economically

have been indicated. The example of the plaice box fact is that not only have few MPAs been estab- emphasizes that wisdom and objective advice will lished in many regions, but where many MPAs not guarantee successful management, but mostly have been gazetted, they have often not been they are sensible preconditions for it. Many have properly managed and so have not met their touched on matters of design (e.g. Carr and Reed objectives (e.g. Stanley 1995; McClanahan 1999). 1993; Dugan and Davis 1993; Rowley 1994; Alli- There are many reasons for this, including lack of son et al. 1998; Ballantine 1999), and I do not intend interest, personnel and money, and opposition to elaborate these further here, beyond what is ex- from other stakeholders. This comes particularly plicit from the empirical and other evidence that I from those who are disadvantaged, as are the fish- have presented. Rather I wish to explore the wider ers by loss of ground. Given the patchy evidence for values and implications of the planning and imple- increased yields of many important resource mentation of MPAs.

species arising from MPAs, it is difficult to promise

MPAs have positive, negative and unknown future fishery benefits. This is so in developing impacts, and it is surprising that MPAs have rarely countries for reasons of rural poverty, but it is also been subject to the environmental impact analyses difficult for small-scale fisheries in developed that are now widely required for most other devel- countries. If the weak evidence for fisheries bene- opments of any size in areas of natural beauty. The fits is considered, there should be little surprise MPAs have positive, negative and unknown future fishery benefits. This is so in developing impacts, and it is surprising that MPAs have rarely countries for reasons of rural poverty, but it is also been subject to the environmental impact analyses difficult for small-scale fisheries in developed that are now widely required for most other devel- countries. If the weak evidence for fisheries bene- opments of any size in areas of natural beauty. The fits is considered, there should be little surprise

Declines over time in several of the world’s marine fish stocks (FAO 1995; Hart and Reynolds, Chapter 1, Volume 1) may constitute a global crisis in capture fisheries (Roberts 1997a), yet, although excessive fishing effort has contributed to decline (e.g. Myers and Barrowman 1996), variation in environmental conditions constitutes a source of great uncertainty for the science, for suitable political decision making and for effective man- agement (e.g. Caddy and Gulland 1983; Botsford et al. 1997). Fluctuations in recruitment have been studied for over a century at higher latitudes (Smith 1994; Smith, Chapter 4, this volume), but substantial variations in year-class strength are now being recognized in some tropical species (e.g. Ferreira and Russ 1995), although probably con- cealed in most fisheries through aggregations of species into broad categories. The arguments that have been presented with respect to the maximiza- tion of spillover and recruitment effects (Table

14.4) highlight the fact that for MPA-orientated fisheries management to be rational, more science is required, just as modern fisheries management has been underpinned by vigorous investigation and reasoned debate (e.g. Smith 1994; Smith, Chapter 4, this volume). It is ironic that MPAs should be confidently advocated as fisheries man- agement measures on the basis of failures in con- ventional fisheries science, when the science underpinning MPAs is in its infancy. This is best il- lustrated by the example of recruitment to and from MPAs, which can clearly be crucial to achievement of management objectives (e.g. Carr and Reed 1993; Allison et al. 1998; Planes et al. 2000). What is required is a clearer picture of how MPAs relate to the wider panoply of fishery man- agement measures, but one difficulty is that, at least in developed countries, the MPA proponents are very different from those responsible for fish- eries management. This may not always be so, but it is worth noting that, in contrast, many less-de- veloped countries such as Malaysia, have fisheries and MPA management under the same govern- mental roof, which may facilitate communica- tion, although interdisciplinary work is no doubt

easier when the variety and volume of information are lower (e.g. Caddy 1999). This is commonly the case in the tropics. In more temperate settings, the social and economic impacts of MPAs and conse- quences of fishery science, which is considered by some to have failed (e.g. Roberts 1997a), are surely similar, and will need similarly to be addressed by politicians and managers if measures in either case are to be a success.

Small MPAs set up in reef habitats for nature conservation and not for fishery purposes, mostly in tropical and subtropical areas (Tables 14.1– 14.3), have provided much of the impetus for the advocacy of MPAs (Bohnsack 1993; Roberts 1997a). However, the overwhelming evidence is that MPAs should typically be a large portion of a fishing-ground if it is to benefit fisheries (e.g. DeMartini 1993; Guénette and Pitcher 1999; Lundberg and Jonzén 1999; Sladek Nowlis and Roberts 1999). Some of the evidence from site- attached species on reefs suggests that increased yields can occur as a result of small MPAs (Table 14.3). Yet the impacts which large-scale oceanic events can have on major fisheries (Hofmann and Powell 1998) highlight the vulnerability of small MPAs, and the findings and inferences from studies of site-attached species, mostly at low lati- tude, and of temperate demersal species, contrast markedly with each other. There are several likely reasons for this, including differences in ecology, and different perceptions of scientists studying them. It is hard to escape the conclusion that MPAs will not everywhere do the same job. They will need therefore to be designed differently and appropriately, but further research is needed to predict the outcomes.

The uncertainties of fisheries outcomes from MPA-orientated management have surely to be treated with openness if such management is to be widely adopted. One means towards open dia- logue, particularly with those who stand most to

be disadvantaged by large-scale area closure, is through participation by fishers in ‘comanage- ment’ (Hart and Reynolds, Chapter 1, this volume). One argument in favour of comanagement derives from the contention that in many parts of the world local communities have traditionally

Marine Protected Areas

309

Chapter 14

managed their resources in areas over which they have tenure (Johannes 1978; Ruddle et al. 1992). Sophisticated tenure does not go hand in hand with a conservation ethic (e.g. Carrier 1987) and the abundant evidence is that such ownership arose for reasons of conflict resolution rather than of resource restraint (e.g. Polunin 1984). The adapt- ability of traditional management to modern man- agement is thus in question, but it should be the case that local users have potential roles to play in resource monitoring and management, and there is some evidence that this is so. For example, in Chile, ‘management and exploitation areas’ owned by local communities have been beneficial in a mollusc fishery (Castilla and Fernandez 1998). This case, together with work in Samoa, highlights the potential uses of cooperative arrangements for knowledge building and promotion of MPAs (e.g. Castilla 1999; King and Faasili 1999). Local man- agement on its own would seem typically to be un- wise for a number of reasons. From work in the Philippines, it is evident that local institutions may be politically vulnerable (e.g. Russ and Alcala 1999), while experience in Fiji indicates that with- out help local institutions may not be good at dis- cerning significant changes in the status of their resources (Fig. 14.5). Further, the Chilean case study points to looming conflict between the sus- tainability of resources and wider management ob- jectives (e.g. Castilla and Fernandez 1998). Rather, the essence of comanagement is that there are some inputs which are best provided by central au- thorities, and others which are most appropriately delivered by the local group concerned.

In the field of nature conservation, where the concern is to protect biodiversity, vulnerable organisms and fragile habitats, the concept of MPAs enters different territory. One reason for this is that the financial value of fragile habitats such as reefs can be so much greater on the basis of tourism than that of fisheries. This linkage with tourism of course brings a danger of visitor-related damage. Then, revenue is not the only benefit to consider, although it is an important outcome recognized by politicians and welcomed by the poor. It is evident that MPAs can contribute much towards such income: well-managed visits to pleasing seascapes

must surely increase the likelihood of a wealthy diver returning to a site and of others visiting and enjoying the environment in turn. And in fact it would appear that in many regions, such as the Caribbean and Southeast Asia, MPAs have been set up with tourism in mind. The most obvious thing that MPAs will do in this respect is to increase the abundance of site-attached species which are vulnerable to fishing, and these are an important part of what divers and snorkellers come to see (Williams and Polunin 2000). Fishes of large size are, however, especially vulnerable to fishing, and these valuable attributes of dive sites need to be conserved, by employing a strict protec- tion regime. It is also probably true that just the hint that MPAs are close, or closer, to the natural state will be sufficient for many ecotourists to visit and dive in them. In relation to biological diversity, the openness of local marine populations and thus their susceptibility to recruitment variability em- phasize that the future of biotic assemblages is not best assured by small MPAs. Either much larger areas are needed or networks of areas are required

Votua

Tavua

Kubuna Verata Ba Levuka Vitogo

Management index

Number of licences per unit reef area (km –2 ) Fig. 14.5 Traditional fishing-grounds (qoliqoli) of Fiji:

variations in management regime (‘yes’ or ‘no’ responses to 26 questions relating to the structure of management, the marshalling of information for management, ap- proach to goodwill payments for licensing, management measures taken or contemplated, and patrolling and enforcement) among the seven qoliqoli which varied in access pressure (number of licences issued per ground). (Source: Cooke et al. 2000.) variations in management regime (‘yes’ or ‘no’ responses to 26 questions relating to the structure of management, the marshalling of information for management, ap- proach to goodwill payments for licensing, management measures taken or contemplated, and patrolling and enforcement) among the seven qoliqoli which varied in access pressure (number of licences issued per ground). (Source: Cooke et al. 2000.)