Genetic Estimates of Variability and Relatedness for Conservation of an Ozark Cave Crayfish Species Complex

Allozyme-based genetic distances were used to determine the distinctness of six species of cave crayfish from the Ozark Plateau in Missouri, Arkansas, and Oklahoma. One of the cave species is in the subgenus Erebicambarus and the others are in Jugicambarus . Four of the six species are very rare and are found in only one to three known sites each. In addition, most populations of all the species are presumed to be small; rarely are more than a few individuals observed. A chela (claw) was collected from sixty individuals representing the six species, including all known populations of the four rare species. Variability and distance estimates were based on 20 presumptive gene loci. Population samples with identical genotypes were pooled. Thirteen loci were polymorphic, but average heterozygosity was low (H= 1%) compared to epigean crayfish species. Pairwise genetic distances within Jugicambarus ranged from D = 0.051 to 0.522, and mean distance between subgenera was D = 0.676. The underground water systems in Ozark caves are defined by discreet recharge zones. Groundwater pollution threatens the stability of cave ecosystems, including the survival of cave crayfish. If restoration of threatened or extirpated populations becomes necessary, a database of genetic variability and relatedness estimates for known populations of all the species will aid decisions about numbers and sources of individuals for propagation or transfer.     

Influence of a Threatened‐Species Focus on Conservation Planning

Abstract: Conservation efforts at local, regional, and global scales often focus on threatened species despite recent calls to adopt more equitable and potentially more economically rational approaches. Critics contend that conservation planning centered only on threatened species fails to deliver cost‐efficient conservation outcomes. We explored how planning to preserve threatened mammal species would influence the efficiency and effectiveness of conservation investments in East Kalimantan, Indonesia. We found that the explicit protection of threatened species delivered cost‐efficient outcomes in this situation, afforded adequate protection to over 90% of those species not yet considered endangered, and contributed to the partial protection of the remainder. We used Marxan, a conservation planning tool, to determine the frequency that planning units are selected in efficient reserve systems and assessed the relative risk of deforestation of each planning unit. Our methods allowed us to identify areas of the region that require the most urgent conservation action.     

ROLE OF SEASON IN AQUATIC HAZARD ASSESSMENT

This paper discusses the potential for time of year toinfluence the outcome of aquatic hazard assessments. Exposureof fish to contaminants under winter conditions can cause themto develop Winter Stress Syndrome (WSS). Substantial mortalitycan result, potentially changing year-class strength andpopulation structure of the affected species, and alteringcommunity-level ecological interactions. Aquatic contaminantsshould be evaluated in the context of seasonal metabolicchanges that normally occur in test organisms. WSS could be animportant, but as yet unquantified, cause of mortality in manycircumstances. Wastewater discharges may pose a greater toxicthreat to fish during winter than at other times of the year.A comprehensive protocol for aquatic hazard assessment shouldinclude testing for WSS.     

WEIGHING CONFLICTING CONCERNS IN FRONTIER DEVELOPMENT

It is no longer perceived that development proposals will automatically assure a net improvement in social well-being. This is particularly so in the case of frontier development. In these areas, information on economic and engineering costs and social and environmental effects is scarce, and projected outcomes from such a base are therefore questionable. The views of indigenous populations living in frontier areas can provide a valuable insight into possible effects of development, as shown in the decision-making process regarding natural gas pipeline construction in the Canadian northwest. Reference to this case suggests that it may be possible to design this process to permit economic development and to assure that environmental, social and local economic objectives are met.     

A Long-Term Monitoring Plan for a Threatened Butterfly

Abstract: A long-term monitoring plan using stratified random sampling of population densities of late instar larvae is presented for a large population of the threatened Bay checkerspot butterfly, Euphydryas editha bayensis. A topographic map of the habitat is analyzed for the distribution of slope exposures and a clear sky insolation model is applied to delineate microclimate strata Sixth and seventh instar larval densities are estimated for square-meter quadrats on specific slope exposures, and these density samples are then grouped into the microclimate strata for estimating population size. Additionally, samples of larvae from different slopes are weighed to monitor developmental phenology. The larval population increased from 92,000 in 1985 to 783,000 in 1987, and decreased to 319,000 in 1988. The distribution of larvae changed between years, shifting from cool slopes to warmer slopes as the population grew. These shifts affect developmental phenology and the timing of adult emergence. The procedure produces labor- and cost-effective yearly estimates of population densities of larvae in different microclimates and documents within-habitat responses of the population to a variable climate.     

Overestimation of Fire Risk in the Northern Spotted Owl Recovery Plan

Abstract:  The U.S. Fish and Wildlife Service's recent recovery plan for one of the most carefully watched threatened species worldwide, the Northern Spotted Owl (Strix occidentalis caurina), recommended a major departure in conservation strategies in the northwestern United States. Due to concern about fire, the plan would switch from a reserve to a no-reserve strategy in up to 52% of the owl's range. Fuel treatments (e.g., thinning) at regular intervals also would occur on up to 65–70% of dry forests in this area. Estimations of fire risk, however, were based on less than a decade of data and an anecdotal assessment of a single, large fire. We found that decadal data are inherently too short, given infrequent large fires, to accurately predict fire risk and trends. Rates of high-severity fire, based on remote-sensing data, are far lower than reported in the plan and in comparison with the rate of old-forest recruitment. In addition, over a 22-year period, there has been no increase in the proportion of high-severity fire. Our findings refute the key conclusions of the plan that are the basis for major changes in conservation strategies for the Spotted Owl. The best available science is needed to address these strategies in an adaptive-management framework. From the standpoint of fire risk, there appears to be ample time for research on fire and proposed treatment effects on Spotted Owls before designing extensive management actions or eliminating reserves.     

Potential Mineral and Energy Resources at Submerged Plate Boundaries

The theory of plate tectonics is briefly reviewed with reference to the recognized association between types of mineral (metals) and energy (hydrocarbons, geothermal) resources that may occur at sites along plate boundaries submerged beneath the oceans. An immense gap in knowledge, technology and economics exists between the potential for mineral or energy resources to occur and the development of the resource as a commercial prospect. The real benefit of mineral discoveries such as polymetallic sulfides at submerged plate boundaries is to feed back information from the seabed to guide exploration for analogous deposits on land. A world map is presented showing the location of submerged plate boundaries and a 200 nautical mile-wide offshore zone. La théorie de la tectonique en plaques est examinée brièvement à la lumière d'associations connues entre les types de mineraux (métaux) et les ressources énergétiques (hydrocarbures, géothermie) qui peuvent se manifester sur des sites au long des plaques submergées par les océans. Il existe une lacune importante en matière de connaissances et de données techniques et économiques entre, d'une part, la presence potentielle de ressources minerales ou energétiques, et d'autre part, la développment de ces ressources dans une perspective de commercialisation. Le benefice réel de découvertes de mineraux tels que les sulfures polymetalliques au long des plaques est celui de fournir des données en provenance du fond de la mer pour l'orientation d'explorations de gisements analogues sur terre ferme. La teoría de placas tectónicas son revisadas brevemente con referencia a la conocida asociación que existe entre tipos de minerales (metales) y energía (hidrocarburos, geotermia) que puedan existir a lo largo de los bordes de placas sumergidas bajo los océanos. Existe un gran vacío de conocimiento, tecnológico y económico, entre el potencial de recursos que pueden existir y el desarrollo comercial de estos recursos. Se espera que los descubrimientos de minerales tales como el de los sulfuros polometálicos en placas sumergidas proveerá información para la exploración de depoAsitos análogos en tierra firme.