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Ferromanganese Micronodules From The Surficial Sediments Of Georges Bank, L. J. Poppe, R. F. Commeau, J. A. Commeau, F. T. Manheim, P. J. Aruscavage Jan 1984

Ferromanganese Micronodules From The Surficial Sediments Of Georges Bank, L. J. Poppe, R. F. Commeau, J. A. Commeau, F. T. Manheim, P. J. Aruscavage

Journal of Marine Research

Ferromanganese micronodules have been found on Georges Bank, off the U.S. northeast coast, distributed throughout the surficial sediments within an area about 125 km long and at least 12 km wide. These coarse, sand-sized concretions have precipitated from metal-rich interstitial waters and contain many of the textural and structural features common to other neritic nodules. Most of the nodules have accreted around detrital grains, and X-ray powder diffraction analyses indicate the presence of geothite and vernadite (δ-MnO2) in the ferromanganese layers. Chemical analyses of the micronodules, when compared with similar data on deep-sea manganese nodules, reveal …

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The Importance Of Microalgae, Bacteria And Particulate Organic Matter In The Somatic Growth Of Hydrobia Totteni, Thomas S. Bianchi, Jeffrey S. Levinton Jan 1984

The Importance Of Microalgae, Bacteria And Particulate Organic Matter In The Somatic Growth Of Hydrobia Totteni, Thomas S. Bianchi, Jeffrey S. Levinton

Journal of Marine Research

Laboratory microcosm experiments reveal that benthic microalgae (filamentous blue-green and diatoms) probably constitute the bulk of nutrition in the somatic growth of the deposit feeding mud snail Hydrobia totteni. Despite an apparent excess of nitrogen in the particulate fraction of the sediment, H. totteni grows only about 42% as much in the dark as in the light. Growth in the dark is probably explained by the utilization of filamentous blue greens and, to a lesser extent, bacteria. The additional growth in the light is probably explained by benthic diatoms, as shown in previous studies. Standing-stocks of micro-organisms (bacteria and …

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Reflection Of Low-Frequency Equatorial Waves At Arbitrary Western Boundaries, Mark A. Cane, Peter R. Gent Jan 1984

Reflection Of Low-Frequency Equatorial Waves At Arbitrary Western Boundaries, Mark A. Cane, Peter R. Gent

Journal of Marine Research

Procedures are developed for calculating effects of western boundaries of arbitrary geometry on low-frequency equatorial waves. We show that the mass flux incident at the coast is all returned eastward by equatorial Kelvin waves. Short Rossby waves generated as part of the reflection serve only to redistribute mass along the coast. For the case of a uniformly sloping coast we present formulae and graphical results for the amplitude of the equatorial Kelvin wave reflected at the coast due to incident free Rossby waves. Results are shown to depend on the single parameter γω where γ is the slope of the …

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Abyssal Eddy Kinetic Energy In The North Atlantic, William J. Schmitz Jr. Jan 1984

Abyssal Eddy Kinetic Energy In The North Atlantic, William J. Schmitz Jr.

Journal of Marine Research

Both eddy and mean fields have similar zonal and meridional scales of geographical variation in the mid-latitude North Atlantic. The first map of the North Atlantic that contained estimates of the intensity of the abyssal eddy field is now several years old, and in the interim the relevant data base has increased roughly six-fold. Contemporary charts are presented, containing these more recent observations, along with some new styles of data presentation. The basic picture of maximum abyssal eddy kinetic energy near the fully developed Gulf Stream is consistently substantiated, along with a two order or magnitude latitudinal decay (from about …

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Effects Of Velocity Fluctuations On Vertical Distributions Of Phytoplankton, Greg Holloway Jan 1984

Effects Of Velocity Fluctuations On Vertical Distributions Of Phytoplankton, Greg Holloway

Journal of Marine Research

Effects of vertical velocity oscillations (associated with high frequency internal gravity waves) upon the vertical distribution of horizontally averaged phytoplankton concentration are considered. It is suggested that such effects have been systematically misrepresented in previous modeling efforts. Correction terms are derived both for averaged quasi-Lagrangian (isopycnal) models and for averaged Eulerian models. In quasi-Lagrangian models, an apparent modification to growth rate coefficient is obtained. In Eulerian models, velocity fluctuations are shown to induce a net vertical transport which can be described by a “virtual velocity” and which is seen as a correction to eddy diffusivity parameterizations. Difficulties such as negative …

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Influence Of Residents On The Development Of A Marine Soft-Bottom Community, William G. Ambrose Jr. Jan 1984

Influence Of Residents On The Development Of A Marine Soft-Bottom Community, William G. Ambrose Jr.

Journal of Marine Research

Field experiments in a Maine estuary were designed to follow community development in newly exposed sediment to determine if resident infauna affect the settlement and survivorship of colonizing infauna and thereby effect changes in community structure. Sets of buckets consisting of control buckets (buckets with previously dried sediment) and two experimental treatments (Nereis virens or Glycera dibranchiata added to dried sediment) were exposed on three dates between June and October 1979 and sampled after 8, 16 and/or 24 weeks. At each sampling, new buckets were established. The index of proportionate similarity comparing the infaunal community of exposure periods with …

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Community Unity: Experimental Evidence For Meiofauna And Macrofauna, Susan S. Bell, Sarah A. Woodin Jan 1984

Community Unity: Experimental Evidence For Meiofauna And Macrofauna, Susan S. Bell, Sarah A. Woodin

Journal of Marine Research

The response of two different size classes of marine benthos, macrofauna and meiofauna, to manipulation of disturbance/predation and size specific utilization of biogenic structural refuges by each benthic size category were studied in an intertidal sandflat in Virginia. A field investigation was conducted during August and September 1980 in the same Diopatra tube system which Woodin (1978; 1981) previously utilized for macrofauna I experiments. Predator/disturber exclusion cages were employed to experimentally evaluate changes in patterns of abundance of both meiofauna and macrofauna in areas of varying Diopatra tube densities (0, 1, 3 or 6 Diopatra 0.01 m–2). Samples …

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Cycling Of Nitrogen By Plankton: A Hypothetical Description Based Upon Efficiency Of Energy Conversion, Dale A. Kiefer, C. Allen Atkinson Jan 1984

Cycling Of Nitrogen By Plankton: A Hypothetical Description Based Upon Efficiency Of Energy Conversion, Dale A. Kiefer, C. Allen Atkinson

Journal of Marine Research

Numerous studies of the nitrogen cycle in the upper ocean have shown that the growth of oceanic phytoplankton is often largely supported by the supply of ammonium excreted by herbivorous zooplankton and members of other tropic levels. Despite considerable knowledge of the growth and metabolic responses of phytoplankton and herbivorous zooplankton to supplies of energy and nutrients, no general quantitative description of nitrogen cycling in the planktonic community has been proposed. Here we present a hypothetical description of a closed, steady state, and well mixed water column in which nitrogen is cycled between a nutrient pool, the crop of phytoplankton, …

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Sediment-Water Exchange In Shallow Water Estuarine Sediments, Steven Emerson, Richard Jahnke, David Heggie Jan 1984

Sediment-Water Exchange In Shallow Water Estuarine Sediments, Steven Emerson, Richard Jahnke, David Heggie

Journal of Marine Research

Pore water profiles in shallow estuarine sediments of Puget Sound show the characteristics of enhanced interstitial-water transport by animal activity. Using an in situ 3H experiment and dissolved silicate profiles we evaluate the transport parameter due to animal activity in the surface 20 cm of sediments to be 1–5 × 10–7 s–1 which is in the range of similar parameters determined in other nearshore environments in the U.S. The fluxes of alkalinity, ammonia and silicate across the sediment-water interface due to biological processes are greater than that by one-dimensional molecular diffusion. For the metals Fe, Mn, Cu, …

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Oxalic, Glyoxalic And Pyruvic Acids In Eastern Pacific Ocean Waters, Spencer M. Steinberg, Jeffrey L. Bada Jan 1984

Oxalic, Glyoxalic And Pyruvic Acids In Eastern Pacific Ocean Waters, Spencer M. Steinberg, Jeffrey L. Bada

Journal of Marine Research

A sensitive high performance liquid chromatographic (HPLC) technique has been used to determine the concentration and distribution of several α-keto acids and oxalic acid in seawater samples from a station (28°29′N, 128°38′W) in the eastern Pacific Ocean. Glyoxalic, pyruvic and oxalic acids were found to be present. Although the pyruvic acid profile at this station was in general featureless, the profiles for glyoxalic and oxalic acids showed variations which could be attributed to both primary production and heterotropic activity. Surface waters were found to have a combined concentration of glyoxalic and oxalic acids of ∼300 to 400 nm/liter which makes …

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On The Equatorial Pacific Response To The 1982/1983 Ei Nino—Southern Oscillation Event, T. Y. Tang, R. H. Weisberg Jan 1984

On The Equatorial Pacific Response To The 1982/1983 Ei Nino—Southern Oscillation Event, T. Y. Tang, R. H. Weisberg

Journal of Marine Research

The ocean's response to the 1982/83 EI Nino—Southern Oscillation event was the largest ever documented. In this paper we explore the effects of certain details of the observed zonal wind stress anomaly field upon the ocean's response using a linear, adiabatic, reduced gravity, analytical model. The increase in magnitude of the downwelling response over the composite of previous EI Nino events is attributed to the eastward translation of the observed westerly wind anomaly and the double peaked downwelling at the South American coast is attributed to the amplitude modulation of this anomaly. Effects of an easterly anomaly which appeared to …

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Observations Of An Internal Resonance In A Fjord, J. R. Keeley Jan 1984

Observations Of An Internal Resonance In A Fjord, J. R. Keeley

Journal of Marine Research

Current meter, CTD and tide gauge data collected in a sill fjord in northern British Columbia are considered. Annual changes in stratification are such that the natural internal period of oscillation of the fjord matches that of the semidiurnal tide in both the spring and fall of the year. Evidence of a semidiurnal internal resonance is sought by calculating the ratio of energy and the relative phase of vertical current shear and the barotropic tide. It is possible to show a strong response in the fall coincides with a phase shift of 180° which is the signature of a resonance. …

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The Effect Of Summertime Shelf Break Upwelling On Nutrient Flux In Southeastern United States Continental Shelf Waters, Larry P. Atkinson, Patrick G. O'Malley, James A. Yoder, Gustav A. Paffenhöfer Jan 1984

The Effect Of Summertime Shelf Break Upwelling On Nutrient Flux In Southeastern United States Continental Shelf Waters, Larry P. Atkinson, Patrick G. O'Malley, James A. Yoder, Gustav A. Paffenhöfer

Journal of Marine Research

Gulf Stream-induced upwelling at the shelf break of the South Atlantic Bight (SAB) presents water which, in summer, can intrude onto the continental shelf. In July 1979, an XBT survey of the continental shelf revealed such an intrusion of cold water off St. Augustine, Florida. From weekly mappings, it was determined that Gulf Stream water <22.5°C covered 3280 km2 and occupied 38 km3 shoreward of the 42 m isobath. Using temperature and nitrate distributions and the T°C:NO3 relationship, we determined that 3200 metric tons of nitrate-nitrogen were advected into the study area. Net nitrate-nitrogen fluxes were 32 μmoles · m …

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Disturbance, Sediment Stability, And Trophic Structure Of Soft-Bottom Communities, P. K. Probert Jan 1984

Disturbance, Sediment Stability, And Trophic Structure Of Soft-Bottom Communities, P. K. Probert

Journal of Marine Research

Previous studies of marine soft-bottom communities have shown (1) that natural disturbances (especially biologically-mediated disturbances, which are usually localized and recur reasonably frequently) help maintain spatio-temporal heterogeneity of communities, and (2) that biogenic modification of sediment can affect sediment stability with respect to fluid forces and geotechnical properties and that this is an important factor in community organization, particularly in the trophic structure of the macrofauna. It is argued in this paper that natural disturbances, and the ensuing biogenic alterations to sediment stability, may be important in maintaining trophically-mixed communities where deposit feeders do not have an overriding influence on …

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Seasonal And Geographic Variation In The Shell Microstructure Of A Salt-Marsh Bivalve (Geukensia Demissa (Dillwyn)), Richard A. Lutz, George R. Clark Ii Jan 1984

Seasonal And Geographic Variation In The Shell Microstructure Of A Salt-Marsh Bivalve (Geukensia Demissa (Dillwyn)), Richard A. Lutz, George R. Clark Ii

Journal of Marine Research

The microstructure of the inner shell layer of Geukensia demissa (Dillwyn) varies with both the season of calcium carbonate deposition (or dissolution) and the latitude of sampled populations. Living specimens (n = 510) were sampled at monthly and, occasionally, biweekly intervals over a 3-year period from a natural intertidal population in Gulf of Maine estuarine waters. Scanning electron microscopic examination of the inner shell layer growth surface and fractured shell sections of the sampled specimens suggests that the observed structural changes reflect seasonal cycles of aragonite deposition and dissolution. Discrete nacreous tablets generally are deposited during the warmer months …

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Summer Phytoplankton Assemblages And Their Environmental Correlates In The Southern California Bight, D. Goodman, R. W. Eppley, F. M. H. Reid Jan 1984

Summer Phytoplankton Assemblages And Their Environmental Correlates In The Southern California Bight, D. Goodman, R. W. Eppley, F. M. H. Reid

Journal of Marine Research

Weekly observations of chemical and physical variables, and of phytoplankton abundances, were made over a 21-week period at three stations in the Southern California Bight. Principal component analysis was employed to resolve four phytoplankton assemblages among the 25 taxa with the highest variances for their log transformed abundances. Two of these components were described by the abundance of taxa characteristic of upwelling assemblages—both dominated by diatoms. A third assemblage was dominated by the "red tide" dinoflagellate, Gonyaulax polyedra, along with some small diatoms and a coccolithophorid.Canonical correlation analysis of the four phytoplankton components against 13 environmental variables revealed distinct sets …

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Particulate Amino Acids In The Sea: Effects Of Primary Productivity And Biological Decomposition, Cindy Lee, Carolyn Cronin Jan 1984

Particulate Amino Acids In The Sea: Effects Of Primary Productivity And Biological Decomposition, Cindy Lee, Carolyn Cronin

Journal of Marine Research

We measured the flux of amino acids associated with sinking particles collected by sediment traps at two Pacific Ocean sites. These results were compared with results from six other sites where we and others have measured amino acid fluxes. This comparison shows that the flux of amino acids on sinking particles is related to primary productivity. This relationship exists in spite of differences in the oceanic regimes sampled and in the sediment traps, bactericides, and amino acid analysis techniques used. The amount of particulate amino acids leaving the euphotic zone in areas of higher productivity is a higher proportion of …

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The Significance Of Subsurface Chlorophyll, Nitrite And Ammonium Maxima In Relation To Nitrogen For Phytoplankton Growth In Stratified Waters Of The Gulf Of Maine, P. M. Holligan, W. M. Balch, C. M. Yentsch Jan 1984

The Significance Of Subsurface Chlorophyll, Nitrite And Ammonium Maxima In Relation To Nitrogen For Phytoplankton Growth In Stratified Waters Of The Gulf Of Maine, P. M. Holligan, W. M. Balch, C. M. Yentsch

Journal of Marine Research

Data on the distributions in summer of phytoplankton and inorganic nutrients in the Gulf of Maine and across Georges Bank are presented. The chlorophyll maximum represents a phytoplankton biomass maximum and occurs at a depth where both light and nitrate availability allow net growth of the population. The dominant species were generally flagellates and included the toxic dinoflagellate, Gonyaulax tamarensis var. excavata, at some stations. The ammonium and nitrite profiles suggest that nitrification is occurring at the base of the pycnocline below the chlorophyll maximum, and this may be an important source of nitrate during the summer months. The highest …

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Bioturbation Processes In Continental Slope And Rise Sediments Delineated By Pb-210, Microfossil And Textural Indicators, J. N. Smith, C. T. Schafer Jan 1984

Bioturbation Processes In Continental Slope And Rise Sediments Delineated By Pb-210, Microfossil And Textural Indicators, J. N. Smith, C. T. Schafer

Journal of Marine Research

Measurements of Pb-210 activities, in conjunction with micropaleontological, geotechnical and sedimentological observations, on sediment cores have been used to characterize two distinctive bioturbation regimes on the continental slope and rise east of Newfoundland. On the rise (2600 m), excess Pb-210 is confined to the upper few centimeters of the coarser-grained sediments underlying the axis of the Western Boundary Undercurrent. The geological and geochemical evidence for a low rate of bioturbation in this high bottom current regime is consistent with a reduced population of deeper burrowing macrofauna, particularly the species Maldane sarsi. In contrast, a higher flux of organic-rich, fine-grained …

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Fisheries Report No 60 - Amateur Net Fishing Survey Of Two Western Australian South Coast Estuaries In January 1981, D. I. Heald Jan 1984

Fisheries Report No 60 - Amateur Net Fishing Survey Of Two Western Australian South Coast Estuaries In January 1981, D. I. Heald

Fisheries Research Reports

Following the return of the administration of fishing activities in Wellstead estuary and Beaufort Inlet to the Western Australian Government in October 1980, a survey of the amateur net fishing in these two estuaries was undertaken in January 1987, The purpose of the survey was to document usage, species catches and size composition of fish caught in respect of mesh size used and the success rate of amateur net fishermen as compared to their expectation. At the time of the survey, Wellstead estuary had been closed to the sea for 13 months and Beaufort Inlet for 27 months and the …

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Double Kelvin Waves In A Two-Layer Sea, S. A. W. Bondok, H. G. Pinsent Jan 1984

Double Kelvin Waves In A Two-Layer Sea, S. A. W. Bondok, H. G. Pinsent

Journal of Marine Research

It is shown that a depth change such as a fault line acts as a wave guide to long period waves in a two-layer rotating sea, in a similar way to the Double Kelvin waves of Longuet-Higgins (1968a, b) for a homogeneous sea. For a sea with a step discontinuity in depth, the effect of an extra layer leads to only small changes in the dispersion characteristics. For a continuous monotonic depth change taking place over a width l it is found that as l increases the Double Kelvin wave period increases, and the elevation at the interface decreases relative …

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An Unstable Uniform Slab Model Of The Mixed Layer As A Source Of Downward Propagating Near-Inertial Motion Part 2: Unsteady Mean Flow, John Kroll Jan 1984

An Unstable Uniform Slab Model Of The Mixed Layer As A Source Of Downward Propagating Near-Inertial Motion Part 2: Unsteady Mean Flow, John Kroll

Journal of Marine Research

The model of the uniform slab model of the mixed layer which was previously analyzed for stability (Kroll, 1982) is modified to include inertial oscillations in the mean flow. The results reflect the nature of the parallel flow instability produced by the steady component of the mean flow combined with the nature of a parametric instability produced by the oscillating component of the mean flow. This model is much more likely to produce unstable perturbations with a near-inertial frequency than the steady mean model which reinforces the contention that the instability can be a source of vertically propagating inertial oscillations. …

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Variations In Primary Production And Particulate Carbon Flux Through The Base Of The Euphotic Zone At The Site Of The Sediment Trap Intercomparison Experiment (Panama Basin), James K. B Bishop, John Marra Jan 1984

Variations In Primary Production And Particulate Carbon Flux Through The Base Of The Euphotic Zone At The Site Of The Sediment Trap Intercomparison Experiment (Panama Basin), James K. B Bishop, John Marra

Journal of Marine Research

C primary production data collected during the deployment and recovery cruises of STIE in 1979 showed a simple relationship with light and nutrient concentrations in the euophotic zone. A simple empirical relationship, calibrated using these data, was derived so that weekly averaged observations of fractional cloudiness, sea-surface temperature and mixed layer depth could be used to estimate primary production on a weekly basis for the years 1976–1979. 15N-uptake measurements, which estimate new production, were combined with the 14C data to estimate particulate carbon fluxes from the euphotic zone. Results of calculations showed that production may vary by a …

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An Estimate Of Bottom Frictional Dissipation By Gulf Stream Fluctuations, Georges L. Weatherly Jan 1984

An Estimate Of Bottom Frictional Dissipation By Gulf Stream Fluctuations, Georges L. Weatherly

Journal of Marine Research

Using published values of the kinetic energy per unit mass of fluctuating motions for the deep western North Atlantic an estimate is made of the energy dissipation rate from fluctuations by bottom friction for the Gulf Stream System. It appears that bottom friction may account for all the energy input by the wind, and that this dissipation occurs in only about 20% of the areal extent of this gyre.

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In Situ Effects Of Selected Preservatives On Total Carbon, Nitrogen And Metals Collected In Sediment Traps, George A. Knauer, David M. Karl, John H. Martin, Craig N. Hunter Jan 1984

In Situ Effects Of Selected Preservatives On Total Carbon, Nitrogen And Metals Collected In Sediment Traps, George A. Knauer, David M. Karl, John H. Martin, Craig N. Hunter

Journal of Marine Research

The concentration and chemical composition of preservative or poison to use in sediment trap studies continue to present an important unresolved question. Past laboratory/field experiments designed to answer this question are difficult to interpret, because so-called analogs have been used instead of actual trap materials, which are compositionally complex. This paper presents our results on the in situ effects of formalin, azide and mercuric ion on material collected in MULTITRAPS set at 100 and 300 m for a period of six days in a coastal environment, and at 150 m for a period of 20.6 days in an oligotrophic environment. …

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Geostrophic Transport In The Warm Water Sphere Of The Eastern Subtropical North Atlantic, Lothar Stramma Jan 1984

Geostrophic Transport In The Warm Water Sphere Of The Eastern Subtropical North Atlantic, Lothar Stramma

Journal of Marine Research

Geostrophic transports in the eastern subtropical North Atlantic computed from historic hydrographic data and recent CTD measurements show a mean transport in the subtropical gyre of 11 ± 1.5 × 106 m3 s–1 in the upper 1000 m between 35W and the African coast. The dynamic method was used in conjunction with a conservation of mass scheme (Fiadeiro and Veronis, 1982) to determine the level of no motion. This level lies in the 1200 m depth near the Azores and drops to 1500 m in the tropics. The main inflow enters south of the Azores as a …

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Episodic Nutrient Supply To A Kelp Forest Ecosystem In Southern California, Richard C. Zimmerman, James N. Kremer Jan 1984

Episodic Nutrient Supply To A Kelp Forest Ecosystem In Southern California, Richard C. Zimmerman, James N. Kremer

Journal of Marine Research

Temporal patterns of nutrient input into a Southern California kelp forest were measured using traditional hydrocast sampling coupled with high frequency temperature profiling. Patterns of nutrient input were related to growth rates of Macrocystis pyrifera located in an adjacent kelp forest. There were 2 distinct components to the pattern of nutrient availability. The long term, or seasonal, component was consistent with large-scale storm-induced mixing and horizontal advection during winter months. In addition, vertical motions of the thermocline, bringing nutrients into the kelp forest, occurred throughout the year with a frequency of about 2 per day and were strongest during the …

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Wave Propagation And Growth On A Surface Front In A Two-Layer Geostrophic Current, Peter D. Killworth, Nathan Paldor, Melvin E. Stern Jan 1984

Wave Propagation And Growth On A Surface Front In A Two-Layer Geostrophic Current, Peter D. Killworth, Nathan Paldor, Melvin E. Stern

Journal of Marine Research

We study analytically and numerically small amplitude perturbations of a geostrophically balanced semi-infinite layer of light water having a surface front and lying above a heavier layer of finite vertical thickness which is at rest in the mean. In contrast with previous studies where the latter layer was infinitely deep we find that the equilibrium is always unstable regardless of the distribution of potential vorticity, and the maximum growth rates are generally much larger than in the "one-layer" case. The amplifying ageostrophic wave transfers kinetic energy from the basic shear flow as well as potential energy. Good quantitative agreement is …

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Effects Of Predators And Food Resources On The Macrobenthos Of Salt Marsh Creeks, Wendy I. Wiltse, Kenneth H. Foreman, John M. Teal, Ivan Valiela Jan 1984

Effects Of Predators And Food Resources On The Macrobenthos Of Salt Marsh Creeks, Wendy I. Wiltse, Kenneth H. Foreman, John M. Teal, Ivan Valiela

Journal of Marine Research

We tested whether predation, disturbance and food resources controlled the density and taxonomic composition of benthic macrofauna in salt marsh tidal creeks by manipulating predator and food abundance. Cages that excluded fish, crabs, and shrimp were placed in two urea fertilized and two control creeks at Great Sippewissett Marsh, MA, in late May 1979 and were sampled over a 15-week period.Densities of macrofauna peaked in early summer, then decreased markedly in natural sediments and inside partial cages that provided access to predator/disturbers. Inside predator exclusion cages, macrofaunal densities increased and remained high throughout the experiment. Comparisons of densities in natural …

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The Role Of Bacterial Exopolymer And Suspended Bacteria In The Nutrition Of The Deposit-Feeding Clam, Macoma Balthica, Ronald W. Harvey, Samuel N. Luoma Jan 1984

The Role Of Bacterial Exopolymer And Suspended Bacteria In The Nutrition Of The Deposit-Feeding Clam, Macoma Balthica, Ronald W. Harvey, Samuel N. Luoma

Journal of Marine Research

Potential nutritional contributions of bacterial exopolymer and suspended bacteria to the detritus feeding estuarine clam, Macoma balthica, were examined separately in laboratory 14C labelling experiments. Significant removal and assimilation of suspended bacteria by M. balthica was observed within two days, although the low clearance rates suggested planktonic bacteria may not be among its major food sources. Sediment-bound and dissolved bacterial exopolymer did not appear to be directly metabolized by M. balthica, as evidenced by the 1–2 week lag in 14C uptake into clam tissue.

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