Physical Sciences and Mathematics Commons^™

Utility Of North Atlantic Right Whale Museum Specimens For Assessing Changes In Genetic Diversity, Howard C. Rosenbaum, Mary G. Egan, Phillip Clapham, Robert L. Brownell Jr., Sobia Malik, Moira Brown, Bradley White, Peter Walsh, Rob Desalle

United States Department of Commerce: Staff Publications

We examined six historical specimens of the endangered North Atlantic right whale (Eubalaena glacialis) using DNA isolated from documented baleen plates from the late nineteenth and early twentieth centuries. Sequences from the mitochondrial DNA (mtDNA) control region from these samples were compared with those from a near-exhaustive survey (269 of approximately 320 individuals) of the remaining right whales in the western North Atlantic Ocean. Our results suggest that there has been only relatively modest change in maternal lineage diversity over the past century in the North Atlantic right whale population. Any significant reduction in genetic variation in the …

Further Scrutiny Of Scientific Whaling, Robert L. Brownell Jr., Michael F. Tillman, Giuseppe Notarbartolo Di Sciara, Per Berggren, Andrew J. Read

United States Department of Commerce: Staff Publications

Normile reports on Japan's expanded scientific whaling program and notes that "Canada, the United States, the Soviet Union, South Africa, and Japan were among several countries that [conducted scientific whaling] before 1982 [the year the IWC passed the worldwide commercial moratorium on whaling], but in recent years Japan has stood alone." Although true, this statement omits three equally important points.

Conservation Conundrum, Robert L. Brownell Jr., Barbara E. Curry, Peter Daszak, Andrew A. Cunningham, Alex D. Hyatt

United States Department of Commerce: Staff Publications

P. Daszak, A. A. Cunningham, and A. D. Hyatt present a convincing argument in their Review "Emerging infectious diseases of wildlife-threats to biodiversity and human health" (Science's Compass, 21 Jan., p. 443) that emerging infectious diseases (EIDs) pose a risk to wildlife, and they suggest that EIDs most often result from a change in the ecology of the pathogen or the host (or both). A situation they did not mention is that in some cases, the protection of threatened species can increase the risk of an EID outbreak by allowing a close association between wildlife and domestic animals where one …

On Measuring Net Ecosystem Carbon Exchange Over Tall Vegetation On Complex Terrain, Dennis Bladocchi, John Finnigan, Kell Wilson, K. T. Paw U, Eva Falge

United States Department of Commerce: Staff Publications

To assess annual budgets of CO₂ exchange between the biosphere and atmosphere over representative ecosystems, long-term measurements must be made over ecosystems that do not exist on ideal terrain. How to interpret eddy covariance measurements correctly remains a major task. At present, net ecosystem CO₂ exchange is assessed, by members of the micrometeorological community, as the sum of eddy covariance measurements and the storage of CO₂ in the underlying air. This approach, however, seems unsatisfactory as numerous investigators are reporting that it may be causing nocturnal respiration flux densities to be underestimated.
A new theory was recently …

Harbor Porpoise (Phocoena Phocoena) Abundance In Alaska: Bristol Bay To Southeast Alaska, 1991-1993, M. Dahlheim, A. York, R. Towell, J. Waite, J. Breiwick

United States Department of Commerce: Staff Publications

Between 1991 and 1993, Alaska harbor porpoise (Phocoena phocoena) abundance was investigated during aerial surveys throughout much of the coastal and offshore waters from Bristol Bay in the eastern Bering Sea to Dixon Entrance in Southeast Alaska. Line-transect methodology was used, and only those observations made during optimal conditions were analyzed. Survey data indicated densities of 4.48 groups/100 km², or approximately 3,531 harbor porpoises (95% C.I. 2,206-5,651) in Bristol Bay and 0.54 groups/100 km², or 136 harbor porpoises (95% C.I. 11-1,645) for Cook Inlet. Efforts off Kodiak Island resulted in densities of 1.85 groups/100 …

Spatial Variation In Density, Mean Size And Physiological Condition Of The Holarctic Amphipod Diporeia Spp. In Lake Michigan, Thomas F. Nalepa, David J. Hartson, Jennifer Buchanan, Joann F. Cavaletto, Gregory A. Lang, Stephen J. Lozano

United States Department of Commerce: Staff Publications

1. We examined spatial patterns in population characteristics (density, biomass, mean body length) and physiological condition (lipid content, length-weight) of the amphipod Diporeia spp. in Lake Michigan by collecting samples at up to 85 sites in late summer 1994 and 1995. Variables were examined relative to water depth and three lake regions: south, central and north. Most major river systems are found in the south, and this region is more nutrient-enriched compared to the north.

2. Over all sites, mean density was 5240 m^-2, biomass was 4.1 g dry wt m^-2, and mean body length was …

Incorporating Uncertainty Into Management Models For Marine Mammals, Barbara L. Taylor, Paul R. Wade, Douglas P. De Master, Jay Barlow

United States Department of Commerce: Staff Publications

Good management models and good models for understanding biology differ in basic philosophy. Management models must facilitate management decisions despite large amounts of uncertainty about the managed populations. Such models must be based on parameters that can be estimated readily, must explicitly account for uncertainty, and should be simple to understand and implement. In contrast, biological models are designed to elucidate the workings of biology and should not be constrained by management concerns. We illustrate the need to incorporate uncertainty in management models by reviewing the inadequacy of using standard biological models to manage marine mammals in the United States. …