• A synopsis of the marine prosobranch gastropod and bivalve mollusks in Alaskan waters

      Foster, Nora Rakestraw (1979-12)
      This study presents information on the taxonomv and distribution of the marine prosobranch gastropod and bivalve mollusks from the waters surrounding Alaska. Three hundred fifty-two species of prosobranch gastropods and 202 species of bivalves are reported from these waters. Over 3,000 lots of specimens, representing 330 species and literature sources form the basis of this study. References, synonymy, geographic and bathymetric ranges are provided for each species. Characteristics used to identify the species of 66 genera are presented in tabular form. The greatest number of species is reported from the southern Bering Sea, the fewest from the Beaufort Sea. Most of the species have wide ranges in the eastern or western Pacific. New collecting records reported here extend the known ranges of 27 species. Eight species were previously unknown from Alaskan waters.
    • Zooplankton ecology of Norton Sound, Alaska

      Neimark, Lee Michael (1979-12)
      The zooplankton distribution in Norton Sound was monitored for the Outer Continental Shelf Environmental Assessment Program. Salinity, temperature, and predation were investigated as factors controlling species composition and community structure. Sampling was concentrated along the eastern coast of Norton Sound during July and August, 1976. The copepod Acartia clausi and the cladocerans Evadne sp. and Podon sp. were numerically dominant in the samples. These species are able to tolerate the widely ranging salinities and temperatures of the coastal waters. The A. clausi population abundance was correlated with water temperature, while cladoceran and larval mollusc populations were correlated with salinity. No differences in species composition were discerned between stations along the shallow coast; however, the seaward community contained a greater diversity of organisms supporting a larger planktonic carnivore biomass. Zooplankton was a numerically dominant item in the diets of many fish species, although the epibenthic mysid community was volumetrically most important.
    • The feeding, movement, and growth of pink salmon, Oncorhynchus gorbuscha, fry released from a hatchery in Prince William Sound, Alaska

      Urquhart, David Lindsay (1979-12)
      As part of a study that investigated the ability of Prince William Sound to support large numbers of juvenile salmon, the movements, feeding, and growth of pink salmon, Oncorhynchus gorbuscha, fry released in the springs of 1977 and 1978 from the Port San Juan hatchery, are described. Fry were released in Sawmill Bay but preferred the waters of adjacent Elrington Passage where they remained for up to two months. Nursery areas in the Passage established by the fry in 1977 were not occupied to the same degree in 1978. Fry fed initially on epibenthic harpacticoid copepods but soon switched to feeding on calanoid copepods. Fry growth rates and diet are comparable with results of other studies. Fry behavior affected sampling and may account for between-year differences detected in growth. Weather, food abundance, and the condition of out-migrants may also account for between-year differences in fry behavior and growth.
    • Light adaptations of plants: a model based on seagrass Zostera Marina L.

      Dennison, William (1979-12)
      Adaptations to light by a temperate seagrass, Zostaro: marina L. (eelgrass), were investigated along a depth transect representing a gradient of plant development. Various light adaptive strategies are proposed in a conceptual model and tested along the natural gradient and under in situ light manipulation experiments. The major light capturing strategy which Zostera employs is that of changing leaf area. Chlorophyll a to b ratios and amounts, measures of adaptation to light quality and quantity, demonstrated little or no adaptive trends when integrative samples were used. The altered light experiments did not affect chlorophyll content but did affect leaf production rates. Although the relative vertical distribution of leaf area is constant along the transect, the absolute leaf area varies, as measured by leaf area index (LAI = area of leaves/area of bottom). A measured maximum LAI of 17 is higher than other aquatic and most terrestrial ecosystems.
    • Diving physiology of the ringed seal: adaptations, capability and implications

      Ferren, Howard Jennings (1980-08)
      Adaptations that influence duration of diving in the ringed seal, Phoaa (Pusa) hispida were examined. Mean blood volume was 234 ml/kg lean body mass (LBM) and oxygen capacity was 30.7 ml O2/100 ml of whole blood, yielding a total blood oxygen capacity of 70 ml O2/kg LBM. Abrupt and prolonged bradycardia occurred upon submersion. Experimental dives indicated submersion durations of up to 18 minutes before the onset of physiological dysfunction. The percentage of LBM represented by the brain is least in the relatively large Weddell seal (0.2%), greater in the harbor seal (0.7%) (the compared species) and greatest in the ringed seal (1.4%); this sets the requirement for minimum obligatory oxygen consumption. The differences observed in diving durations between the three species is considered to be mainly the consequence of brain/body size relationship.
    • Phosphorus metabolism of several aquatic microorganisms

      Lang, Douglas; Brown, E. J. (1980-12)
      Several taxonomically diverse aquatic microplankton were described growing at phosphorus (P) concentrations that limit growth in many natural aquatic systems. Because natural aquatic systems are subject to periodic fluctuations in P levels, both steady-state (via continuous culture) and transient (via batch culture) growth were described. Complete growth kinetic descriptions of Synechococcus Nageli (strain A) and Scenedesmus quadricauda were used to predict the relative competitive abilities of these species when P was the growth-limiting nutrient. These descriptions, coupled to their morphological characteristics, were used to construct partial physiological profiles for each organism. The profiles indicate that S. Nageli (strain A) (a small unicellular blue-green alga) is better suited for growth in P-limited oligotrophic niches than is S. quadricauda (a green alga). However, results from kinetic experiments with these and several other microplankton, show that such physiological profiles are not necessarily indicative of profiles for taxonomically related species.
    • The Concept Of Microbial Affinity For Limiting Nutrients In Steady State And Rhythmic Systems

      Molot, Lewis Arnold; Brown, E. J. (1981)
      To evaluate the role of biological rhythms in competition for survival, rhythms in cell division and limiting nutrient transport ability induced by light/dark (LD) cycles were investigated for three species of pelagic, freshwater algae growing in phosphoruslimited continuous and serially diluted batch (SDB) cultures. Nutrient transport ability of nutrient-starved microbial populations was measured as the initial slope (affinity) of a plot of limiting nutrient transport rate (V) versus extracellular limiting nutrient concentration (S). A method was devised for the determination of the affinity in continuous culture (a(,T)) by monitoring S with time. Cell division was asynchronous for the green alga, Selenastrum capricornutum, grown in LD continuous cultures and a rhythm in a(,T) for soluble reactive phosphate (Pi) was greatly affected by choice of biomass parameter. Division was strongly phased in LD SDB culture and weakly phased in continuous light (LL) SDB culture, indicating that nutrient perturbations have a greater effect on phasing of division than LD cycles for S. capricornutum. A rhythm in Pi transport rate in LD SDB culture was similar to the rhythm in continuous culture a(,T) when expressed per cell volume or cell dry weight but not when expressed per cell number. Cell division was phased for the green alga, Scenedesmus quadricauda, grown in LD continuous culture. A rhythm in a(,T) for Pi was not greatly affected by choice of biomass parameter. Cell division was also rhythmic in LD for the blue-green alga, Synechococcus Nageli. Synechococcus was an extremely efficient Pi transporter at low Pi concentrations in LD continuous culture, indicating that it should be widespread in oligotrophic systems and has probably been overlooked in past floristic studies.
    • Toxins And Toxicity Of Protogonyaulax From The Northeast Pacific

      Hall, Sherwood (1982)
      Dinoflagellates of the genus Protogonyaulax contain a group of substances that can be lethal to many creatures, including man, and may accumulate at many points in the food web. The substances are most familiar as paralytic shellfish poison (PSP), which occurs sporadically in bivalves. The present study was undertaken because previous work left in doubt both the origin and chemical nature of the toxins along the Alaskan coast. To investigate the problem, dinoflagellates were isolated from locations along the Pacific coast ranging from San Francisco to Dutch Harbor. Most isolates were obtained by incubating subtidal sediments to germinate resting cysts. Toxic isolates were obtained from most locations sampled. On the basis of morphology, all toxic isolates fell within the genus Protogonyaulax. The growth and toxicity of one clone (PI07) was studied under a variety of culture conditions. Toxicity was greatly suppressed under the conditions traditionally employed for culturing Protogonyaulax, suggesting that the toxicity of cells in nature may in general be higher than has been recognized. Chemical studies of the toxins extracted from Protogonyaulax revealed that the six toxins previously known (saxitoxin, its N-1-hydroxyl and 11-hydroxysulfate derivatives) are generally accompanied by somewhat larger amounts of their 21-sulfo derivatives. These have likely not been recognized in past studies due to their greatly reduced toxicity, facile hydrolysis, and altered chromatographic properties. The toxin composition of several isolates was determined and indicates that toxin composition is a conservative property of each clone and that there are regional populations of Protogonyaulax with uniform toxin composition, but that toxin composition differs substantially among regions. This pattern of variation, coupled with the great differences in the properties of the toxins, indicates that the nature of PSP will similarly vary from one region to another but will be uniform within each.
    • Bathymetry of Alaskan arctic lakes: a key to resource inventory with remote-sensing methods

      Mellor, Jack C. (1982-05)
      Water depth is a major factor in predicting resources associated with tens-of-thousands of uninventoried Alaskan arctic lakes. Lakes were studied for physical, chemical, and biological resources related to water depth in 3 specific areas along a north/south transect extending from Pt. Barrow on the Arctic Ocean to the foothills of the Brooks Range. Side-Looking Airborne Radar (SLAR) imagery was acquired over the same study transect to investigate its application for determining lake depth. Ice thicknesses, necessary for the interpretation of depth contours from SLAR imagery, were measured along with other parameters in the study lakes throughout the winter 1978-79. This ice-thickness data and sequential SLAR images are used to illustrate a method of contouring water depths in arctic lakes. This is based on changes in intensity of SLAR signal return which define the zone at which ice cover contacts the bottom. This intensity is a function of physical and dielectric properties of the snow, ice, water, bottom substrates, and ice inclusions within these lakes. A computer program was developed to manipulate Landsat satellite digital data and compile a master file of lakes and their computer-calculated surface features (i.e. area, perimeter, crenulation, and centroid). The master file uniquely identifies each computer catalogued lake by latitude and longitude and stores the calculated features in a data base that can be retrieved for a specified geographic ABSTRACT area. Each lake record also provides storage space for resource data collected outside the computer generated data. The application of these remote-sensing tools and the knowledge of aquatic resources associated with bathymetry add to our ability for regional inventory, classification, and management of arctic lake resources.
    • Satellite evidence of physical features and processes in the Bering Sea

      Paluszkiewicz, Theresa (1982-05)
      Satellite infrared imagery is used to study temporal and spatial relationships of physical features and processes in the Bering Sea. A two-year collection of enhanced infrared imagery reveals that the maximum extent of the ice corresponds with the location of the Bering Slope current. Sea surface temperature patterns visually correlate with the 50-m and 70-m bathymetric contours. Processes which establish fronts in these regions are possible explanations for this correlation. Warm surface water extending from the Gulf of Alaska, through the Aleutian passes into the Bering Sea, is found simultaneously with warm surface water and eddies along the shelf break. Spatial and temporal relationships of these patterns imply surface circulation in the Bering Sea basin with inflow of Gulf of Alaska water through the Aleutian passes, cyclonic flow in the basin, and flow along the shelf by the Bering Slope current. Several generating mechanisms for the eddies are proposed.
    • The Geochemistry Of Manganese, Iron And Phosphorus In An Arctic Lake

      Cornwell, Jeffrey Clayton (1983)
      Sediment redox processes were investigated in an oligotrophic, arctic lake containing metal oxide crusts in oxidizing surficial sediments (up to 22% Mn and 26% Fe). Toolik Lake, Alaska, a 12,000 year old kettle lake, has the lowest Pb-210 derived sedimentation rates reported for any lake (27 g m('-2) yr('-1)). Three independent methods for estimation of Mn, Fe and P retention within the lake (stream budgets, sediment traps and sediment burial rates) provide similar rates. Of the amounts entering the lake, 28% of P, 50% of Mn and 55% of Fe are retained. Common water column removal mechanisms for these elements and organic C are suggested by sediment trap data. A steady state diagenetic model with terms for diffusion, reduction and oxidation shows that Mn and Fe crusts migrate within surficial sediments. Metal oxide burial rates are equivalent to oxide dissolution rates (reduction), rates of upward diffusion of soluble divalent metals and metal precipitation rates (oxidation). High inputs of labile Mn and Fe from streams, plus low sedimentation and organic matter oxidation rates are important for crust formation. Approximately 12% of Mn and 2% of acid reducible Fe retained by the lake since its formation exist as diagenetic oxides; the rest is buried within reducing sediment. Sediment inorganic P migrates with Fe to form P enriched sediment zones with pore water PO(,4) concentrations beneath these zones regulated by vivianite (Fe(,3)(PO(,4))(,2) 8H(,2)O) formation. The migration of Mn and Fe within sediments results in the enrichment of Ba, Co, Ca, Ni, Ra-226 and carbonate in metal oxide enriched sediments. Barium is enriched in Mn crusts because of diagenetic migration.
    • Hemocyte and tissue changes by crude oil in the blue mussel Mytilus edulis

      McCormick-Ray, M. Geraldine (1983)
      This study examines the effects of Prudhoe Bay crude oil on the number and types of circulating hemocytes, on the phagocytic response, on spawning progression, and on internal structural changes. The number of hemocytes was reduced with 4-5 week exposure to 1000 nL/L of oil; a significant number of individuals showed a higher than average cell count with longer exposure. An increase in agranulocytes in the 8-9 week control population does not occur in populations exposed to 1000 nL/L and 500 nL/L of oil for 8-9 weeks, but, the phagocytic response was significantly depressed. The Chi-square test showed that oil interferes significantly with progression of spawning. Analysis of internal tissue structure indicates that oil can affect adipogranular storage cells, vesicular tissue, and digestive tubule cells. The changes occurring in circulating hemocytes are not necessarily consistent with changes in internal morphology.
    • The effects of water temperature on the seasonal distribution and growth of walleye pollock, Theragra chalcogramma (Pallas), in the southeast Bering Sea

      Chen, Lih-Feng (1983-05)
      The distribution and growth of walleye pollock, Theragva ohalaogvamna (Pallas), were studied in relation to bottom water temperatures, in an area between latitude 54°30'N and 57°30'N and longitude 160°W and 170°W, from the data collected from 1976 to 1980. The annual variations of bottom temperature distribution, including mean temperature, are described. It is found that temperature boundaries regulate spawning aggregation areas and feeding distribution of adult pollock. Young pollock were distributed in a wider temperature range and revealed a clearer feeding migration pattern than the adults. The weight growth for walleye pollock aged 2 to 4 was determined. The growth rate varied with age, sex and year. The relative growth rate was related to the initial weight of the fish and the mean temperature. Additional seasonal variations in the length-weight relationship and condition factor were observed.