Premachandra Wattage

Total economic value of wetland conservation in Sri Lanka identifying use and non-use values

In tropical regions, mangroves, clean (unpolluted) water-bodies and fish are important aspects of wetland areas, which are considered as the basic requirement for livelihood improvement in local communities. Particularly, their conservation is very important to both inland as well as inshore fisheries. However, conservation of such areas is dependent on the perceptions of key stakeholders in the area. A novel approach of a one and one-half bound based contingent valuation method (CVM) was implemented to measure the stakeholder willingness to pay (WTP) towards the conservation of fish, mangroves and water in a Sri Lankan wetland area. Estimated median WTP is Rs. 264.26, which is thought reliable when considering average income in the community. The analytic hierarchy process (AHP) was used to separate use and non-use values from the total value. Results show that non-use values are a significant component in the elicited WTP value, of between 45-55%. In the past such commodities have been assigned zero or low values due to difficulties involved in assigning economic values.

Optimal harvesting strategies: Practice versus theory

Abstract Over the last decade or so, a number of bioeconomic models have been developed with the expressed objective of identifying the optimal time to harvest farmed fish. The models explicitly incorporate growth rates, prices and costs, but have generally excluded risk except implicitly through the discount rate. Implicit in this is the assumption that risk is continuous, such that the probability of significant changes in key parameters (e.g. prices, mortality rates etc) is independent of time. In reality, these factors can vary over time. In this paper, the optimal harvesting strategies for two farmed species were analysed using a bioeconomic model. The model was based on previous models applied in the literature, with a new feed‐use component applied. The theoretical ‘optimal’ harvest strategy was compared with actual behaviour, and the factors that may affect divergences in the results examined.

Fishing capacity and capacity utilization of purse seiners using data envelopment analysis

The existence of excessive fishing capacity is globally recognized by resource managers as a major problem for fisheries, and it is responsible for the degradation of fishery resources and for significant economic waste. Estimates of fishing capacity and capacity utilization may provide helpful tools in designing an effective capacity management plan for Mediterrane an fisheries. In this study, the fishing capacity and capacity utilization of eastern Mediterranean purse seiners were assessed using data envelopment analysis (DEA). Estimates were made for individual vessels based on the level of inputs used and outputs produced, relative to other vessels operating under similar conditions. Results indicated similar excess capacity for target species, which is in accordance with how the fishery operated. The 24–40-m fleet segment was found to be more efficient than the 12–24-m fleet segment in terms of landing weights. It was evidenced that purse seiners could have increased their catch during 2000–2005 by approximately 23% by increasing the variable inputs, for example days fished. Conversely, a fleet of smaller size could have achieved the reported catch. Under the condition that the remaining vessels will be fully utilized, a proportional decrease in the fleet size might seem a rational management measure towards reducing overexploitation and attaining sustainable fisheries in the eastern Mediterranean Sea.

Integrating environmental impact, contingent valuation and cost-benefit analysis: empirical evidence for an alternative perspective

The non-market nature of water quality improvement in rivers hinders the use of traditional cost-benefit analysis (CBA) to measure the efficiency of investments. Substantial investments have been made to clean up contaminated river water with little comparison of the costs or environmental impact (EI) with future benefits. Water quality impact models are used in this study to predict the impact of discharges on downstream water quality. Contingent valuation (CV) is used to measure the total value, including use and non-use, of river water quality improvement. This provides the benefit side of the cost-benefit equation. The method outlined provides a tool to evaluate investment on environmental improvement integrating EI and CV in CBA.

EVALUATION OF COMMUNITY PARTICIPATION FOR THE DEVELOPMENT OF CULTURE-BASED FISHERIES IN VILLAGE RESERVOIRS OF SRI LANKA

In this paper, an attempt is made to identify the socioeconomic characteristics of a community that influence the development and management of culture-based fisheries in village reservoirs of Sri Lanka. Socioeconomic data were collected from 46 agricultural farming communities associated with 47 village reservoirs in Sri Lanka. Principal component analysis indicated that scores of the first principal component were positively influenced by socioeconomic characteristics that are favorable for making collective decisions. These included leadership of the officers, age of the group, percentage of active members of the group, percentage of kinship of the group, percentage of common interest of the group, and percentage of participation of the group. The size of the group had a negative effect on the first principal component. The principal component scores of communities were positively related to willingness to pay (P < 0.001). The communities with socioeconomic characteristics favoring collective decision making were in favor of culture-based fisheries. Homogeneity of group characteristics facilitated successful development of culture-based fisheries.