Conservation of Pacific Sea Turtles

Chapter 4. Can We Improve Our Conservation Bang for the Buck?: Cost-Effectiveness of Alternative Leatherback Turtle Conservation Strategies

60 CHAPTER 4 Can We Improve Our Conservation Bang for the Buck? Cost-Effectiveness of Alternative Leatherback Turtle Conservation Strategies HeiDi gjertSen Pacific leatherbacks are among the most endangered sea turtles in the world. Threats to leatherbacks in the Pacific include at-sea mortality from fishing interactions and egg and hatchling mortality due to loss of nesting habitat, nest predation, egg harvest, and other beach-related activities . A number of scientific forums have agreed that addressing all sources of mortality is necessary to enable recovery of Pacific sea turtle populations (e.g., the Bellagio Blueprint and the FAO technical consultation). However, because society has limited resources to undertake actions to assist recovery of populations of endangered species, we must make decisions about how to prioritize these actions. In general, efforts to prioritize have focused on the question of which actions can yield the greatest biological impact (benefits). For example, calculating elasticities can reveal interventions that will yield the largest increase in the population growth rate per unit increase in survival. Different strategies result in different benefits in terms of the population, and it is sensible to pursue activities that maximize these benefits. However, what if high-impact activities also tend to be relatively costly? If this is the case, then it is not evident that these are the actions that should be pursued. There may be other activities that have a lower absolute impact but yield a greater impact per dollar. Because there are limited resources for the purpose of turtle conservation , those programs that generate the greatest net benefits are the ones that should be chosen, according to the economic efficiency criterion. In Can We Improve? | 61 addition, when alternative programs are not mutually exclusive and may be combined at various levels, efficiency requires that each program should be implemented to the level at which the last dollar invested in each program returns the same benefit, where the benefit in this case is the marginal reduction in turtle mortality.1 If the marginal benefit of one program is much higher than that of another, additional funds should keep being allocated to that program until the marginal benefit of the programs become equal.2 This economic rule for the optimal allocation of resources is called the Equimarginal Principle (Tietenberg 2003). When either programs cannot be implemented at continuously varying scales (“lumpy investments”) or there are greater than proportional benefits from increasing the scale of competing programs, then a discrete choice of one program over another may be optimal. The “biggest bang for the buck” principle implies that the program providing the greater benefits for a given cost or the program costing the least to achieve a particular welfare goal should be undertaken. This is the principle of cost-effectiveness, which prioritizes conservation strategies that result in greater impacts for a given cost, according to the biological impact (benefit) divided by the economic cost of the action. In this manner priority is given to actions that have the greatest biological impact relative to the economic cost of producing that impact. In evaluating two conservation strategies, efficiency might require some of both—equating the marginal benefit in each program of the last dollar spent—or efficiency might suggest one strategy instead of the other as the cheaper alternative to achieve a given reduction in turtle mortality. Measuring the costs and benefits of conservation investments is an inherently challenging task. There are still scant data for estimating basic life history parameters for population models for species such as leatherback turtles. Thus the population trajectory even without conservation investments is uncertain. In addition, it is difficult to measure the impacts of conservation projects on the population and attribute changes in population parameters to the existence of the project. Finally, besides requiring good information on operating costs of these projects, other factors must be accounted for correctly, including externalities and market distortions, using the appropriate prices (shadow prices for nonmarketed goods and services, exchange rates), distinguishing among different types of costs (private versus social, incremental costs, common costs), and others. There is uncertainty surrounding all of these estimates; thus the analysis in this chapter presents the best possible estimates from the best available data and conducts sensitivity analysis on the results. Future analysis will incorporate uncertainty directly into the decision model. 62 | HeiDi gjertSen This chapter considers the question of how to allocate society’s resources toward different conservation strategies.3 Given the...