Rd October 2010 [a] Contents

Sue Stolton and Jorge Alejandro Rickards-Guevara

In 1976, Professor of Botany, Dr Hugh Iltis, at the University of Wisconsin-Madison in the US, sent a New Year’s card in the form of a poster to botanists around the world with a picture of Zea perennis against which he wrote “extinct in the wild”. Wild populations of Z. perennis had last been seen in 1921 in Western Mexico, by two US Department of Agriculture botanists, who introduced the species to university greenhouses. Since then several other botanists had tried, and failed, to locate the wild population. One poster was placed on a bulletin board at the University of Guadalajara by a local taxonomist, who urged her students: “Go and find this teocintle, and prove that gringo Iltis wrong”. One undergraduate student took the challenge and went back to the plant’s last known location in Western Mexico and found the long-lost Z. Perennis (Stolton et al, 2006).

Following this discovery, years of negotiations led eventually to the creation of the Sierra de Manantlán Reserve under the direction of the University of Guadalajara – the first protected area in Mexico established principally for the preservation of a wild crop relative, along with traditional agricultural systems and cultivars (Iltis,1994). Steps towards protection began in 1984, when the State of Jalisco purchased land which included a large population of Z. diploperennis. The following year this area became the Laboratorio Natural Las Joyas de la Sierra de Manantlán run by the Universidad de Guadalajara. The area was recognised by UNESCO’s Man and the Biosphere Programme in 1988 and is currently under the administration of the National Comission for Protected Areas (CONANP).

The discovery of Z. diploperennis and the subsequent declaration of a biosphere reserve have together led to intensive research into the biodiversity, and specifically the flora of the reserve, which includes tropical humid forest and temperate grasslands. Over 2,700 plant species have been recorded, of which 40 per cent are endemic to Mexico. Agricultural fields and associated secondary vegetation in hillsides and small valleys in the reserve and surrounding area have been found to contain CWR of beans (Phaseolus coccineus and P. vulgaris) as well as maize. The Sierra de Manantlán is also an important refuge for animals, including threatened species such as the jaguar (Panthera onca). So far, 108 species of mammals have been recorded in the region at least 12 of which are endemic to montane areas of western Mexico and 2 subspecies to the reserve (Cuevas-Guzmán et al, undated).

Sierra de Manantlán’s success as a protected area is not just due to the work carried out by scientists and conservationists. Mexicans call teocintle the ‘grain of the gods’ and the crop is of great importance to food security in the region. The reverence accorded to the species has clearly helped to preserve its diversity.

Nigel Dudley and Sue Stolton

Nearly 40 per cent of the global population now lives within 100 kilometres of a coast, and many of these people depend on the productivity of the sea. But, the Millennium Ecosystem Assessment has assessed that: “The use of two ecosystem services – capture fisheries and freshwater – is now well beyond levels that can be sustained even at current demands, much less future ones (Millennium Ecosystem Assessment, 2005).

With the global crisis in fish stocks, small-scale fishing communities are extremely vulnerable; marine protected areas with regulated and sustainable small-scale fishing activities generally increase the amount of fish landed within two years of establishment. In theory larger and more representative systems of protected areas can provide an even greater range of benefits. It has been estimated that an ambitious target of conserving 20-30 per cent of the world’s seas could create around one million jobs, increase the sustainability of a global marine fish catch (worth around US$70–80 billion per year) and ensure the sustainability of marine ecosystem services with a gross value of roughly US$4.5–6.7 trillion a year (Balmford et al, 2004).

Although this chapter concentrates on marine fisheries, inland (i.e. freshwater) fisheries are extremely important sources of nutrition and income around the world. For example, Cambodia’s inland fisheries have an annual value of up to US$500 million with 60 per cent coming from Tonle Sap Lake (a UNESCO Man and Biosphere reserve) (ICEM, 2003) – see case study on Lake Malawi. [!box ends!]

In a broad review undertaken for WWF, Roberts and Hawkins (2000) identified five main benefits of MPAs to fisheries.

1. 
   Enhancing the production of offspring to restock fishing grounds: MPAs create sheltered conditions that help to enhance fish breeding and overall population. Three factors are important: fish size, habitat and life cycle. First, MPAs help conserve fish of all ages. Overfishing often removes most of the older members of the population, but bigger fish generally produce many more eggs than smaller ones and are thus disproportionately important for breeding. For example one ten kilogramme red snapper (Lutjanus campechanus) produces over twenty times more eggs at a spawning than ten one kilogramme snappers. Second some species, especially those that are attached or have limited powers of movement (e.g., oysters, clams or abalones), only reproduce successfully at high population densities. Protecting these species’ habitat can thus enhance reproduction (Roberts and Hawkins, 2000). Third, MPAs can ensure that species are protected at vulnerable stages of thier life cycle, in particular fish nurseries and spawning grounds, thus increasing the chances that fish reproduce before being caught. This approach has been used in Florida Bay where lobsters are protected in reserves until they are large enough to migrate to the reefs where they may be captured. The Florida Keys National Marine Sanctuary is a 9,850 km² MPA protecting mangroves, seagrass and coral reef habitats; including a network of 24 fully protected zones. Monitoring results show increases in the number and size of heavily exploited species such as spiny lobster within these zones (Keller et al, 2003).
   

Researchers conclude that fish density, and thus presumably reproduction, is generally higher inside MPAs, particularly when surrounding areas are heavily fished (Pérez-Ruzafa et al, 2008). A review of 112 independent studies in 80 different MPAs found strikingly higher fish populations inside the reserves compared with surrounding areas (or the same area before an MPA was established). Relative to reference sites, population densities were 91 per cent higher, biomass 192 per cent higher, and average organism size and diversity 20–30 per cent higher in MPAs, usually between one and three years after establishment. These trends occurred even in small MPAs (Halpern, 2003).

2. 
   Allowing spillover of adults and juveniles into fishing grounds: Since most fish have free-floating larvae or eggs, the offspring of protected animals can drift out of reserves – re-stocking distant fishing grounds. As fish stocks build up inside reserves, juvenile and mature fish move out to populate nearby areas. Six factors affect spillover: the success of protection; the time that the MPA has been established; intensity of fishing outside the MPA; mobility of species; boundary length of the reserve (with greater edge to area ratio increased spill-over); and boundary porosity, with out-migration encouraged if there is continuous habitat type (Roberts and Hawkins, 2000).
   

3. 
   Preventing habitat damage: all fishing creates some damage: trawling and use of dynamite are the most serious but even line fishing results in disturbance and litter that can damage bottom-living communities.
   

4. 
   Promoting development of natural biological communities (which may be different from communities in fishing grounds): For example in Chile establishment of an MPA led to a replacement of mussel beds with barnacles, due to recovery of a predatory snail Concholepas concholepas, which controlled the former (Castilla and Duran, 1985).
   

5. 
   Facilitating recovery from catastrophic human disturbance: Healthy ecosystems are more resistant to major disruptions than ecosystems weakened by over-exploitation. Studies of recovery of coral reefs from major disturbances found that healthy reefs, with good populations and reproduction rates, are more resilient and recover relatively quickly, while reefs suffering from multiple stresses show little or no recovery (Connell, 1997).
   

A body of evidence for the effectiveness of MPAs in increasing fish numbers and spillover effects is developing rapidly (table 4).

Despite the fact that MPAs are increasingly recognised as a vital conservation tool, there are far less protected areas in marine environments than on land. Currently, about 12 per cent of marine coastal (intertidal) areas are protected, but only 4 per cent of the marine shelf (i.e. areas of over 200m depth) recieved protection (Coad et al, 2009). And it is estimated that up to 80 per cent of the world’s MPAs have little or no management. Of particular concern is the lack of protection for coral reefs and mangrove forests, the high seas, particularly sensitive areas at risk from shipping activities and breeding grounds for commercially important fish (WWF, undated).

An FAO study concluded that the current mangrove area worldwide has fallen below 15 million hectares, down from 19.8 million ha in 1980 and that mangrove deforestation continued, albeit at a slightly lower rate in the 1990s (1.1 percent per annum) than in the 1980s (1.9 percent per annum). This in mangrove deforestation reflects that in recent years most countries have banned conversion of mangroves for aquaculture and require environmental impact assessments prior to large-scale conversion for other uses (Wilkie and Fortuna, 2003).