Jocelyne Ferraris

Integrated coastal zone management perspectives to ensure the sustainability of coral reefs in New Caledonia.

Based on a pluridisciplinary research programme on New Caledonias lagoon (2004-2008), this paper addresses economic, ecological and political issues in order to implement integrated coastal zone management (ICZM) in this French Pacific territory. The nickel mining industry constitutes the core of the re-balancing economic and social strategy between the Northern and Southern provinces. But major impacts on the coastal environment of metal-processing plants, harbours, and decades of mine exploitation have released a controversy. A short diachronic analysis suggests that such environmental concerns prompted the emergence of collective actions to among civil society, customary and institutional stakeholders. The inscription of New Caledonia lagoon and reef areas in the UNESCO World Heritage List in 2008 would be both an outcome and a catalyst of this on-going process. Looking beyond the reefs towards the mainland and watersheds for the construction of local socio-ecological systems, we assume that the current stakes could result in the initiation of ICZM in New Caledonia.

Evaluation of large-scale unsupervised classification of New Caledonia reef ecosystems using Landsat 7 ETM+ imagery

The capacity of the Landsat 7 Enhanced Thematic Mapper Plus sensor to classify the shallow benthic ecosytems of New Caledonia (South Pacific) is tested using a novel unsupervised classification method. The classes are defined by using a set of multiple spectral decision rules based on the image spectral bands. A general model is applied to the entire Southwest lagoon (5500 km2) and tested on three representative sites: a section of the barrier reef, a cay reef flat rich in corals, and a cay reef flat rich in algae and seagrass beds. In the latter one, the classification results are compared with a locally optimized model, with aerial color photographs and extensive ground-truthed observations. Results show that a reconnaissance of the main benthic habitats in shallow areas (<5 m depth) is possible, at a geomorphological scale for coral reef structure and at a habitat scale for seagrass beds. However, results directly issued from the model must be cautiously interpreted according to empirical spatial rules, especially to avoid confusion between coral slopes and shallow dense seagrass.

Geographical aspects of informal reef fishery systems in New Caledonia.

The coral reefs in New Caledonia have long been used by the local population for subsistence as well as commercial and recreational purposes. The impact of informal fisheries on reef ecosystems illustrated the idiosyncrasies of New Caledonian fisheries in the southwest Pacific. This paper compared informal fishery systems on the southwest coast (close to the capital and economic center of the country) and the northwest coast (where an industrial mining complex has been under development) of New Caledonia to analyze their spatial structure and characteristics. Four geosystems were defined. These depended on the natural, social and economical environments as well as management strategies. The way of life of the fishers proved to be a major factor in how the informal fishery systems were structured. Our observations suggested that ongoing socio-economic changes in New Caledonia have shaped informal fishing activities since the 1900s. The findings from this study validate the suitability of spatial approaches to coral reef fisheries and provide local stakeholders with original management clues for marine resources sustainability.

Decadal increase in the number of recreational users is concentrated in no-take marine reserves

In coastal areas, demographic increase is likely to result in greater numbers of recreational users, with potential consequences on marine biodiversity. These effects may also occur within Marine Protected Areas (MPAs), which are popular with recreational users. Our analysis builds on data collected over a ten-year period during three year-round surveys to appraise changes in recreational boating activities in coral ecosystems. Results show that the number of boaters has greatly increased, particularly so within MPAs during weekends and the warm season, when peaks in boat numbers have become more frequent. We also observed that the number of anchored boats has increased over the period. These changes may be resulting in biophysical impacts that could be detrimental to conservation objectives in MPAs. This steady increase over time may cause changes in the spatial and temporal distribution of users and in their practices, thus highlighting the importance of monitoring recreational activities.