Dinuclear complexes of CU(I), PD(I), PT(I) and RU(I) : catalysts for the electrochemical reduction of CO2.

Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2001.No abstract available

Human migration and marine protected areas: insights from Vezo fishers in Madagascar

Human migration may negatively impact biodiversity and is expected to increase in future, yet the phenomenon remains poorly understood by conservation managers. We conducted a mixed-methods investigation of a contemporary migration of traditional fishers in western Madagascar, a country which has been expanding its protected area system through the establishment of both strict and multiple-use sites, and critically evaluate different models of marine protected area in light of our findings. Interviews with fishers in major destination areas revealed that most migrants come from southwest Madagascar, use non-motorised vessels, and principally target sharks and sea cucumbers. Drivers of the migration include both push and pull factors (i.e. declining resource availability in areas of origin and the continued availability of lucrative resources for export to China). Traditional fisher migrants cause limited social conflict with residents and a number of environmental problems in destination areas: however artisanal fishers with motorised vessels probably represent a greater threat to marine resources than migrants, due to their greater harvesting capacity. We suggest that multiple-use arrangements may be more appropriate than strict protected areas in both source and destination areas, because they integrate the interests of migrants rather than marginalising them: however seascape-scale management provides the best approach for managing the threats and opportunities provided by the migration at the appropriate scale

Ecological variability and carbon stock estimates of mangrove ecosystems

Abstract: Mangroves are found throughout the tropics, providing critical ecosystem goods and services to coastal communities and supporting rich biodiversity. Despite their value, world-wide, mangroves are being rapidly degraded and deforested. Madagascar contains approximately 2% of the world's mangroves, >20% of which has been deforested since 1990 from increased extraction for charcoal and timber and conversion to small to large-scale agriculture and aquaculture. Loss is particularly prominent in the northwestern Ambaro and Ambanja bays. Here, we focus on Ambaro and Ambanja bays, presenting dynamics calculated using United States Geological Survey (USGS) national-level mangrove maps and the first localized satellite imagery derived map of dominant land-cover types. The analysis of USGS data indicated a loss of 7659 ha (23.7%) and a gain of 995 ha (3.1%) from 1990-2010. Contemporary mapping results were 93.4% accurate overall (Kappa 0.9), with producer's and user's accuracies ≥85%. Classification results allowed partitioning mangroves in to ecologically meaningful, spectrally distinct strata, wherein field measurements facilitated estimating the first total carbon stocks for mangroves in Madagascar. Estimates suggest that higher stature closed-canopy mangroves have average total vegetation carbon values of 146.8 Mg/ha (±10.2) and soil organic OPEN ACCESS Forests 2014, 5 178 carbon of 446.2 (±36.9), supporting a growing body of studies that mangroves are amongst the most carbon-dense tropical forests

A decade and a half of learning from Madagascar’s first locally managed marine area

While the participatory management of small scale fisheries has been widely promoted, we have limited understanding of the factors influencing its effectiveness. Here, we highlight lessons learnt from the implementation of Madagascar’s first locally managed marine area (LMMA), drawing on our insights and experiences as staff of a co-managing non-governmental organisation (NGO). We describe the LMMA’s context and history, and highlight aspects of our approach that we feel underpin its outcomes, including: i) co-management rather than community-management, ii) the permanent field presence of a supporting NGO, iii) a management focus on locally-important natural resources, iv) the implementation of poverty-alleviation initiatives aimed at reducing barriers to management, v) decision-making by resource users rather than scientists, vi) a diversified, entrepreneurial funding model, and vii) an emphasis on monitoring and adaptive management. We also highlight several challenges, including: i) the inability to influence fishery supply chains, ii) promoting participation and good governance, iii) promoting rule application, iv) standing up to outsiders, v) promoting environmental management in the long term, and vi) maintaining funding. Our experiences suggest that small scale fishers can be effective natural resource managers in low income contexts, but may need extended support from outsiders; however the role of supporting NGO is nuanced and complex

Ecological Variability and Carbon Stock Estimates of Mangrove Ecosystems in Northwestern Madagascar

Mangroves are found throughout the tropics, providing critical ecosystem goods and services to coastal communities and supporting rich biodiversity. Despite their value, world-wide, mangroves are being rapidly degraded and deforested. Madagascar contains approximately 2% of the world’s mangroves, >20% of which has been deforested since 1990 from increased extraction for charcoal and timber and conversion to small to large-scale agriculture and aquaculture. Loss is particularly prominent in the northwestern Ambaro and Ambanja bays. Here, we focus on Ambaro and Ambanja bays, presenting dynamics calculated using United States Geological Survey (USGS) national-level mangrove maps and the first localized satellite imagery derived map of dominant land-cover types. The analysis of USGS data indicated a loss of 7659 ha (23.7%) and a gain of 995 ha (3.1%) from 1990–2010. Contemporary mapping results were 93.4% accurate overall (Kappa 0.9), with producer’s and user’s accuracies ≥85%. Classification results allowed partitioning mangroves in to ecologically meaningful, spectrally distinct strata, wherein field measurements facilitated estimating the first total carbon stocks for mangroves in Madagascar. Estimates suggest that higher stature closed-canopy mangroves have average total vegetation carbon values of 146.8 Mg/ha (±10.2) and soil organic carbon of 446.2 (±36.9), supporting a growing body of studies that mangroves are amongst the most carbon-dense tropical forests

Madagascar’s Mangroves: Quantifying Nation-Wide and Ecosystem Specific Dynamics, and Detailed Contemporary Mapping of Distinct Ecosystems

Mangrove ecosystems help mitigate climate change, are highly biodiverse, and provide critical goods and services to coastal communities. Despite their importance, anthropogenic activities are rapidly degrading and deforesting mangroves world-wide. Madagascar contains 2% of the world’s mangroves, many of which have undergone or are starting to exhibit signs of widespread degradation and deforestation. Remotely sensed data can be used to quantify mangrove loss and characterize remaining distributions, providing detailed, accurate, timely and updateable information. We use USGS maps produced from Landsat data to calculate nation-wide dynamics for Madagascar’s mangroves from 1990 to 2010, and examine change more closely by partitioning the national distribution in to primary (i.e., \u3e1000 ha) ecosystems; with focus on four Areas of Interest (AOIs): Ambaro-Ambanja Bays (AAB), Mahajamba Bay (MHJ), Tsiribihina Manombolo Delta (TMD) and Bay des Assassins (BdA). Results indicate a nation–wide net-loss of 21% (i.e., 57,359 ha) from 1990 to 2010, with dynamics varying considerably among primary mangrove ecosystems. Given the limitations of national-level maps for certain localized applications (e.g., carbon stock inventories), building on two previous studies for AAB and MHJ, we employ Landsat data to produce detailed, contemporary mangrove maps for TMD and BdA. These contemporary, AOI-specific maps provide improved detail and accuracy over the USGS national-level maps, and are being applied to conservation and restoration initiatives through the Blue Ventures’ Blue Forests programme and WWF Madagascar West Indian Ocean Programme Office’s work in the region