Stratified bongo net samples taken at depths between 0 and 500 m at Ocean Station “P” in the subarctic Pacific in early July 1971 have been analyzed to determine the vertical structure of the zooplankton community. Distributions for 99 categories of animals have been grouped by factor analysis into five...
Several species of the copepod genus Acartia are shown from existing data to complete each molt-to-molt phase of the life cycle in a constant time period. This molting pattern is termed isochronal development. Increase in mass at each stage is a nearly constant fraction of the weight at the beginning...
The spatial distribution of plankton is highly aggregated, so one might expect that a vertically migrating animal enters a biotic environment that is markedly different each evening and that the changes in environment between daylight periods spent at depth are equally great. To measure the extent of these changes, as...
An attempt has been made to interbreed populations of Acartia clausi from Woods Hole, Massachusetts, and Yaquina Bay, Oregon. Individuals from these populations are morphologically similar, but differ somewhat in size. Cultures from both sources produced many successive generations in the laboratory, but interbreeding with production of viable offspring did...
Axenic cultures of 25 species of unicellular marine algae were tested for their ability to utilize nine common amino acids, supplied at high concentrations in batch culture, as a nitrogen source; most species were able to use several amino acids, although growth was often slower than on nitrate nitrogen. The...
The seasonal variation in the alongshore velocity field is inferred from direct current observations made over the Oregon continental shelf at various locations and irregular intervals since 1965. Monthly mean currents are computed and compared with earlier studies to give a description of the seasonal variation in the alongshore currents....
A total of 19 species of hyperiid amphipods was collected from 1963 to 1967 off Oregon.
Parathemisto pacifica, Paraphronima gracilis, Streetsia challengeri, Tryphana malmi, Hyperia
medusarum, Hyperoche medusarum, and Primno macropa were common. New distributional
records are reported for Scina crassicornis bermudensis and Lanceola loveni. Abundance and
occurrence of common...
Three general types of swimbladders were found in the eight species of myctophids studied: gas-filled, fat-invested, and atrophied or reduced. Small specimens of all species had thin-walled, gas-filled swimbladders. Large specimens of Stenobrachius leucopsarus had fat-invested swim-bladders and large Diaphus theta had either gas-filled or atrophied swimbladders, as found by...
A new midwater trawl for sampling deepsea nekton from discrete
depths is described. Its mouth area is about 50 m2. The trawl body is
lined with small mesh netting and terminates in a 5-net opening-closing
codend device. Problems of delayed flushing of animals into the codend
and of entanglement of...
Demersal fishes were sampled at seven stations located inshore of Heceta Bank, on Oregon's continental shelf, over a 2-yr period with a 3-m beam trawl designed to catch small fiatfishes. Two general assemblages of fishes were recognized: a shallow water 74-102 m), sandy-bottom association where Pacific sanddab, Citharichthys sordidus,was numerically...
Pandalis jordani Rathbun, like many other species of pandalid shrimps, undergo regular diel changes in their vertical distribution (Tegelberg and Smith 1957; Alverson et al. 1960; Pearcy 1970, 1972; Robinson in press). Little is known, however, about the vertical distribution and diel migrations of larval and juvenile shrimp, or at...
The feeding habits of the Dover sole and rex sole (mainly juveniles) and of slender sole and Pacific sanddab were investigated at seven stations on the continental shelf off central Oregon. Dover sole had a catholic diet, feeding on a large variety of infaunal and epifaunal invertebrates. The composition of...
The existence of a distinct coastal zone is confirmed in Lake Tahoe (California-Nevada) by horizontal transects measuring chlorophyll and temperature simultaneously. Creation of the coastal region is influenced by bottom topography, the nature of the surface wind stress, and the difference between physical processes occurring within a Rossby radius of...
Particle size distributions (8-105-μm diameter), chlorophyll a, and particulate carbon
were measured off the Oregon coast during July 1973. The particle counts were transformed
to volume concentration and then subjected to characteristic vector analysis.
Ninety-two percent of the variance was accounted for by linear combinations of the first
two characteristic...
One hundred and seventy pairs of temperature and light transmission profiles were obtained by simultaneous conductivity-temperature-depth (CTD) and light transmissometer casts in three cruises on the R/V Yaquina over the continental shelf off Oregon. These were analyzed for bottom nepheloid layers (BNL) and bottom mixed layers layers (BML). Supplementing these...
Suspended matter in Astoria canyon was monitored by means of an in situ nephelometer and by means of light-scattering and particle concentration measurements performed aboard ship on water samples. Nephelometer profiles obtained along the axis of the canyon in February and April 1973 indicate that the canyon is divided into...
Measurements of total irradiance versus depth and beam transmission versus depth were made at
stations near shore along the west coast of the North and South American continents. The water types at
each station were optically classified according to the system of Jerlov (1976), thus providing additional
information for the...
The distribution of suspended matter in the Panama basin was determined by means of
light scattering and Coulter counter measurements on water samples collected at 50 hydrographic
stations. The observed distribution indicates three probable sources of suspended
matter: (1) the surface waters throughout the basin; (2) erosion and runoff from...