Physical Sciences and Mathematics Commons^™

Lissodelphis Peroni, Michael W. Newcomer, Thomas A. Jefferson, Robert L. Brownell Jr.

United States Department of Commerce: Staff Publications

Order Cetacea, Suborder Odontoceti, Family Delphinidae. The subfamily Lissodelphinae has been proposed for this genus (Fraser and Purves, 1960), but it has not been universally accepted (Kasuya, 1973). There are two species in the genus: Lissodelphis peronii (southern right whale dolphin) and L. borealis (northern right whale dolphin). Lissodelphis peronii currently contains no subspecies.

Assessment Of The Status Of Harbor Porpoise (Phocoena Phocoena) In Oregon And Washington Waters, S. Osmek, J. Calambokidis, J. Laake, P. Gearin, R. Delong, J. Scordino, S. Jeffries, R. Brown

United States Department of Commerce: Staff Publications

The status of harbor porpoise, Phocoena phocoena, is reviewed for stocks in Oregon and Washington waters, and the adjacent transboundary waters of southern British Columbia, Canada, emphasizing the most recent data on their geographic range, population structure, distribution, population size, trends in abundance, and reproductive biology. This information is used to determine if the annual rate of incidental mortality and serious injury in gill-net fisheries from 1990-94 could be at a biologically significant level.

In the eastern North Pacific Ocean, harbor porpoise are found near the coast, generally in water depths of less than 200 m. Differences in harbor porpoise …

Changes In The Freshwater Mussel Community Of Lake St. Clair: From Unionidae To Dreissena Polymorpha In Eight Years, Thomas F. Nalepa, David J. Hartson, Gerald W. Gostenik, David L. Fanslow, Gregory A. Lang

United States Department of Commerce: Staff Publications

To determine density changes in both the zebra mussel, Dreissena polymorpha, and native mussels, Unionidae, in Lake St. Clair, surveys were conducted in 1990, 1992, and 1994 and compared to a similar survey in 1986 when no D. polymorpha was found. Collection methods were the same each year; divers used the quadrat method to collect 10 replicate samples at 29 sites located throughout the lake. The total number of unionids collected declined from 281 in 1986, to 248 in 1990, 99 in 1992, and 6 in 1994, while the number of species collected in each of the four respective …

Zebra Mussel Infestation Of Unionid Bivalves (Unionidae) In North America, Don W. Schloesser, Thomas F. Nalepa, Gerald L. Mackie

United States Department of Commerce: Staff Publications

In 1989, zebra mussels received national attention in North America when they reached densities exceeding 750,000/m² in a water withdrawal facility along the shore of western Lake Erie of the Laurentian Great Lakes. Although water withdrawal problems caused by zebra mussels have been of immediate concern, ecological impacts attributed to mussels are likely to be the more important long-term issue for surface waters in North America. To date, the epizoic colonization (i.e., infestation) of unionid bivalve mollusks by zebra mussels has caused the most direct and severe ecological impact. Infestation of and resulting impacts caused by zebra …