Marine biological diversity : report of a meeting of the Marine Biological Diversity Working Group

On August 3 - 4, 1989, the Marine Policy Center of Woods Hole Oceanographic Institution hosted the initial meeting of the Marine Biological Diversity Working Group. The formation of this working group was fostered as part of an ongoing program of research concerning the oceans and biological diversity. Participants in the working group included professionals from the fields of biology, ecology, economics, statistics, law, environmental management, and international assistance, all of whom have expressed an interest in issues surrounding the conservation of marine biological resources. The proposed goals of the working group are to initiate an ongoing interdisciplinary dialogue on the topic, to establish a mechanism for two-way transfer of theory and empirical results between natural and social science, and to serve as a resource for policymakers by providing authoritative and timely information on important issues. This report contains information about the working group and the motivations for its formation, a description of the format of the initial meeting, key points from each of the sessions, abstracts of research/issue briefings delivered at the meeting by participants, selected excerpts from group discussions, and an amended version of a draft working group statement that was introduced to the group for purpose of discussion. The appendices contain the agenda of the meeting, a list of the names and addresses of working group participants, and a list of key questions and issues submitt before the meeting by the working group.Funding was provided by The Pew Charitable Trusts

The Ghost of Extinction: Preservation Values and Minimum Viable Population in Wildlife Models

The inclusion of a minimum viable population in bioeconomic modeling creates at least two complications that are not resolved by using a modified logistic growth function. The first complication can be dealt with by choosing a different depensational growth function. The second complication relates to the inclusion of the in situ benefits of wildlife into the analysis. Knowledge about the magnitude of the in situ benefits provides no guide for policy about conservation management. Simply knowing that people are willing to pay a large amount each year to protect a species says nothing about whether one should manage habitat to protect or enhance the species numbers, unless the species is in imminent danger of extinction. If willingness to pay is to be a guide, it needs to be better tied to population numbers, especially the minimum viable population.marginal willingness to pay, endangered species and extinction, minimum viable population, Resource /Energy Economics and Policy, Q20, Q24, C61,

Prevention or Control: Optimal Government Policies for Invasive Species Management

We present a conceptual, but empirically applicable, model for determining the optimal allocation of resources between exclusion and control activities for managing an invasive species with an uncertain discovery time. This model is used to investigate how to allocate limited resources between activities before and after the first discovery of an invasive species and the effects of the characteristics of an invasive species on limited resource allocation. The optimality conditions show that it is economically efficient to spend a larger share of outlays for exclusion activities before, rather than after, a species is first discovered, up to a threshold point. We also find that, after discovery, more exclusionary measures and fewer control measures are optimal, when the pest population is less than a threshold. As the pest population increases beyond this threshold, the exclusionary measures are no longer optimal. Finally, a comparative dynamic analysis indicates that the efficient level of total expenditures on preventive and control measures decreases with the level of the invasive species stock and increases with the intrinsic population growth rate, the rate of additional discoveries avoided, and the maximum possible pest population.invasive species, exclusion, control, eradication, public expenditures, Environmental Economics and Policy, Resource /Energy Economics and Policy,

THE PLIGHT OF CRANES: A CASE STUDY FOR CONSERVING BIODIVERSITY

Cranes provide an exemplary case for evaluating conservation policy because (1) they are a charismatic group with high public visibility, (2) as migratory vertebrates they provide an umbrella for the protection of aquatic habitats and a wider set of species, (3) they are a widely-distributed avian family, consequently protection efforts have favored international cooperation, (4) genetic and taxonomic relationships have been studied, and (5) populations of at least 7 crane species are threatened, endangered, or otherwise considered at direct risk. We use comparisons among the world\u27s cranes to show how biogeographic, taxonomic, and genetic data bases can be linked for conservation decisions. We show that decisions typically faced by a conservation planner are themselves diverse (e.g., choosing species for captive propagation, or identifying priority habitats for maintaining taxonomic distinctiveness), thereby obviating the utility of any single, all-purpose measure of diversity. Conservation priorities are shown to change with successive informational input regarding phylogenetic relationships, extinction risks, and popUlation trends, and to differ greatly from priorities based on species richness alone

Using Dynamic Optimization for Integrated Environmental Management: An Application to Solvent Waste Disposal

The choice of disposal strategy for a residuals stream often determines the environmental medium into which the pollution is released. In turn, choice of medium may influence both the kinds of adverse effects that the pollution will have and the timing of those effects as well. As an illustration of the way in which these factors may be taken into account in integrated environmental management, this paper demonstrates the application of a dynamic optimization model to the problem of allocating a pollutant between two different disposal methods. The alternatives examined are incineration and land disposal for metal-bearing solvent waste.

The Ghost of Extinction: Preservation Values and Minimum Viable Population in Wildlife Models

The inclusion of a minimum viable population in bioeconomic modeling creates at least two complications that are not resolved by using a modified logistic growth function. The first complication can be dealt with by choosing a different depensational growth function. The second complication relates to the inclusion of the in situ benefits of wildlife into the analysis. Knowledge about the magnitude of the in situ benefits provides no guide for policy about conservation management. Simply knowing that people are willing to pay a large amount each year to protect a species says nothing about whether one should manage habitat to protect or enhance the species' numbers, unless the species is in imminent danger of extinction. If willingness to pay is to be a guide, it needs to be better tied to population numbers, especially the minimum viable population

Dynamic Programming and Learning Models for Management of a Nonnative Species

"Nonnative invasive species result in sizeable economic damages and control costs. Because dynamic optimization models break down if controls depend in complex ways on past controls, nonuniform or scale-dependent spatial attributes, etc., decision-support systems that allow learning may be preferred. We compare two models of an invasive weed in California's grazing lands: (i) a stochastic dynamic programming model and (ii) a reinforcement-based, experience-weighted attraction (EWA) learning model. We extend the EWA approach by including stochastic forage growth and penalties for repeated application of environmentally harmful controls. Results indicate that EWA learning models offer some promise for managing invasive species." Copyright 2007 Canadian Agricultural Economics Society.

The Ghost of Extinction: Preservation Values and Minimum Viable Population in Wildlife Models

The inclusion of a minimum viable population in bioeconomic modeling creates at least two complications that are not resolved by using a modified logistic growth function. The first complication can be dealt with by choosing a different depensational growth function. The second complication relates to the inclusion of the in situ benefits of wildlife into the analysis. Knowledge about the magnitude of the in situ benefits provides no guide for policy about conservation management. Simply knowing that people are willing to pay a large amount each year to protect a species says nothing about whether one should manage habitat to protect or enhance the species’ numbers, unless the species is in imminent danger of extinction. If willingness to pay is to be a guide, it needs to be better tied to population numbers, especially the minimum viable population