This report summarizes the recent state of the California Current System (CCS), primarily during the period of April 2004 to January 2005. The report is based on observations made between Oregon and Baja California by various ocean observing programs. The CCS was not forced by any coherent basin-wide processes during...
This report describes the state of the California Current System (CCS)—meteorological, physical, chemical, and biological—from January 2003 to the spring of 2004. The area covered in this report ranges from Oregon coastal waters to southern Baja California. Over the past year, most physical, chemical, and biological parameters were close to...
Heceta Bank is a large reef on the edge of the central Oregon continental shelf that supports a wide variety of commercial fisheries. Using the research submersible Delta, we studied fish abundances on Heceta Bank and the relationship between species composition of fish assemblages and bottom types. Cluster analysis indicated...
This report summarizes physical and biological conditions in the California Current System (CCS), from Oregon to Baja California, in 2001 and 2002. The principal sources of the observations described here are the CalCOFI (California Cooperative Oceanic Fisheries Investigations), IMECOCAL (Investigaciones Mexicanas de la Corriente de California), and U.S. GLOBECLTOP (Global...
Submersible belt-transect surveys along a rocky bottom were combined with acoustic surveys of the water column to estimate depth distribution and density of fishes at Stonewall Bank, Oregon in the northeastern Pacific Ocean from September through October 1991. The objectives of the study were to determine the proportion of fish...
Terrestrial land use activities present cross-ecosystem threats to riverine and marine species and processes. Specifically, pesticide runoff can disrupt hormonal, reproductive, and developmental processes in aquatic organisms, yet non-point source pollution is difficult to trace and quantify. In Oregon, U.S.A., state and federal forestry pesticide regulations, designed to meet regulatory...
Salmonid fish raised in hatcheries often have lower fitness (number of returning adult offspring) than wild fish when both spawn in the wild. Body size at release from hatcheries is positively correlated with survival at sea. So one explanation for reduced fitness is that hatcheries inadvertently select for trait values...
Grass carp Ctenopharyngodon idella are sometimes used as a biological tool for managing aquatic vegetation in reservoirs. Sterile, triploid fish were stocked in Devils Lake, Oregon, during 1986, 1987, and 1993 to control aquatic vegetation. We present a case study for using multiple measures on the same fish to determine...
Dual-axis accelerometer global positioning system collars can be used to remotely record the activity level and behavior of free-ranging animals, but inter- and intraspecific variations in motion among behaviors necessitate calibration for each species of interest. To date, little work has been done to determine the best duration for sampling...