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The Mythical Thermohaline Oscillator?, Barry Ruddick, Lingqi Zhang Jan 1989

The Mythical Thermohaline Oscillator?, Barry Ruddick, Lingqi Zhang

Journal of Marine Research

The system discussed by Stommel (1987) and Welander (1982), in which heating and evaporation at the surface of the ocean are balanced by vertical turbulent mixing, is studied analytically and numerically for mixing laws appropriate to salt fingers, rather than mechanical turbulence. Stommel and Welander found for mechanically-driven turbulent mixing that a limit cycle of T and S exists (that is, T and S oscillate) in the presence of steady forcing. We find that the usual salt finger parameterizations, in which salinity flux coefficient and buoyancy flux ratio decrease with increasing density ratio, do not allow a limit cycle. This …

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Lead-210 And Polonium-210 In Pteropod And Heteropod Mollusc Shells From The North Pacific: Evaluation Of Sample Treatments And Variation With Shell Size, Victoria J. Fabry, Margaret L. Delaney Jan 1989

Lead-210 And Polonium-210 In Pteropod And Heteropod Mollusc Shells From The North Pacific: Evaluation Of Sample Treatments And Variation With Shell Size, Victoria J. Fabry, Margaret L. Delaney

Journal of Marine Research

Lead-210 activities in carefully cleaned size groups of pteropod and heteropod shells from the eastern equatorial Pacific were typically 0.3 dpm/g shell, similar to those reported in other biogenic calcium carbonates. However, 210Po activities were in excess of levels expected from the decay of shell-incorporated 210Pb, with (210Po/210Pb) activity ratios ranging from 20 to 28 in size-fractionated samples. Sample treatment procedures were examined using pteropod shells collected from diverse locations of the North Pacific. Possible sources of 210Po in excess of 210Pb in shells include inclusion of 210Po in the organic …

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Mechanisms Of Subsurface Thermal Structure And Sea Surface Thermohaline Variabilities In The Southwestern Tropical Pacific During 1975-85, Thierry Delcroix, Christian Hénin Jan 1989

Mechanisms Of Subsurface Thermal Structure And Sea Surface Thermohaline Variabilities In The Southwestern Tropical Pacific During 1975-85, Thierry Delcroix, Christian Hénin

Journal of Marine Research

Major features of the southwestern tropical Pacific (SWTP), defined between 160E–140W and 24S–10S, are brought to light through analysis of surface water samples (23000) and temperature/depth observations (8500), both collected by ship of opportunity programs during the 1979–85 period. The mean vertical thermal structure (and its related parameters), mean sea surface temperature (SST) and salinity (SSS) are first portrayed, to further quantify the 1979–85 variability. It is demonstrated that the observed seasonal and interannual variabilities, the latter being associated with the strong 1982–83 EI Niño Southern Oscillation (ENSO) event, are mostly governed by specific mechanisms involving varying wind field and …

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The Response Of The Coastal Ocean To Strong Offshore Winds: With Application To Circulations In The Gulfs Of Tehuantepec And Papagayo, Julian P. Mccreary Jr., Hyong S. Lee, David B. Enfield Jan 1989

The Response Of The Coastal Ocean To Strong Offshore Winds: With Application To Circulations In The Gulfs Of Tehuantepec And Papagayo, Julian P. Mccreary Jr., Hyong S. Lee, David B. Enfield

Journal of Marine Research

Two ocean models are used to investigate the response of the coastal ocean to strong offshore winds: a linear 1½-layer model, and a nonlinear 1½-layer model that allows entrainment of cool water into the surface layer. The models are forced by wind stress fields similar in structure to the intense winter-time, mountain-pass jets (∼20 dyne/cm2) that appear in the Gulfs of Tehuantepec and Papagayo for periods of 3–10 days. Solutions are arranged in a hierarchy of increasing dynamical complexity, in order to illustrate the important physical processes. They compare favorably with observations in several ways. Some properties of …

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Longitudinal Dispersion Of Suspended Particles In Oscillatory Currents, Hidekazu Yasuda Jan 1989

Longitudinal Dispersion Of Suspended Particles In Oscillatory Currents, Hidekazu Yasuda

Journal of Marine Research

This study has investigated theoretically longitudinal dispersion of suspended fine particles with settling velocity and revealed the dispersing behavior from the initial to the stationary stages in tidal oscillatory currents. A Stokes layer of the oscillatory current plays a remarkably significant role on dispersion of settling particles when the mixing time in cross-section is larger than the period of tidal oscillation. When the settling velocity exceeds a certain value, however, the dispersion coefficient of particles decreases with increasing settling velocity. In an oscillatory current with linear profile, settling velocity of dispersing particles decreases the value of the dispersion coefficient all …

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Microscale And Finescale Variations Of Small Plankton In Coastal And Pelagic Environments, R. W. Owen Jan 1989

Microscale And Finescale Variations Of Small Plankton In Coastal And Pelagic Environments, R. W. Owen

Journal of Marine Research

Small-interval water sampling in oceanic subsurface layers in a variety of macroenvironments for microplankton and for characteristics of their environment revealed concentration variations that often exceed errors of sampling and measurement. I report incidence and degree of microscale and finescale organism patchiness and their dependency on the local environment and on certain characteristics of the organisms themselves. Scale analysis indicates that patchiness occurs below as well as above the 20 cm intervals sampled. Incidence and degree of patchiness were about the same in separate eastern boundary regions, off California and Perú. Effects of environmental characteristics on organism patchiness are clearly …

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Derivative Analysis Of Spectral Absorption By Photosynthetic Pigments In The Western Sargasso Sea, R. R. Bidigare, J. H. Morrow, D. A. Kiefer Jan 1989

Derivative Analysis Of Spectral Absorption By Photosynthetic Pigments In The Western Sargasso Sea, R. R. Bidigare, J. H. Morrow, D. A. Kiefer

Journal of Marine Research

Concurrent measurements of the spectral absorption coefficient and photosynthetic pigmentation of natural particulates were performed to determine the principal pigments responsible for the absorption of spectral irradiance in seawater. The spectral absorption coefficient, Ap(λ), was then analyzed by taking the second and fourth derivatives with respect to wavelength. The wavelength and magnitude of these derivative values provide useful information regarding the identification and quantification of phytoplankton pigments responsible for a given spectral signature. Linear relationships were examined and established between derivative values at selected wavelengths and concentrations of the major tetrapyrrole pigments, specifically chlorophylls a, b, and …

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Wind-Driven Ocean Circulation And Equilibrium Statistical Mechanics, Annalisa Griffa, Rick Salmon Jan 1989

Wind-Driven Ocean Circulation And Equilibrium Statistical Mechanics, Annalisa Griffa, Rick Salmon

Journal of Marine Research

In this paper, we show that numerical solutions of the single-layer quasigeostrophic equation in a beta-plane basin approach the state predicted by equilibrium statistical mechanics when the forcing and dissipation are (unrealistically) zero. This equilibrium state, which we call Fofonoff flow, consists of a quasi-steady uniform westward interior flow closed by inertial boundary layers. When wind stress and bottom drag are switched on, we find that the nonlinear terms in the quasigeostrophic equation still try to drive the flow toward Fofonoff flow, but their success at this depends strongly on the geometry of the wind stress. If the prescribed wind …

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On The Interaction Of Wind And Buoyancy Driven Gyres, Alain Colin De Verdière Jan 1989

On The Interaction Of Wind And Buoyancy Driven Gyres, Alain Colin De Verdière

Journal of Marine Research

The steady large scale oceanic response to wind stress and a surface buoyancy flux is studied by making use of a numerical model based upon the planetary geostrophic equations for which scales of motions smaller than the internal Rossby radius of deformation have been filtered out. In regions of both heat gain and Ekman convergence, the forcings combine to create a strong subtropical gyre in the upper thermocline. The north-south symmetry imposed by the wind pattern is broken because in a region of heat loss the density field shoals through the action of convection and the result is a broad …

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Large-Scale Sst Anomalies Associated With Subtropical Fronts In The Western North Atlantic During Fasinex, George R. Halliwell Jr., Peter Cornillon Jan 1989

Large-Scale Sst Anomalies Associated With Subtropical Fronts In The Western North Atlantic During Fasinex, George R. Halliwell Jr., Peter Cornillon

Journal of Marine Research

We describe the large-scale variability of sea surface temperature (Ts) and fronts in the western North Atlantic Subtropical Convergence Zone from January–June 1986 within an approximately 11° longitude by 10° latitude domain. Fronts were primarily found within interconnected bands separated by <500 km that tended to be located on the periphery of anisotropic Ts spatial anomaly features that propagated westward at about 3 km day–1. Relatively weak and strong (small or large |∇Ts|) segments of the dominant zonally-oriented frontal band (the Subtropical Frontal Zone, or SFZ) shifted westward with these anomaly features, which had characteristic peak-to-peak space scales of up to ≈800 km …

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Density Of The Major Size Groups Of Benthic Fauna And Trophic Input In Deep Basins Of The Atlantic Ocean, Myriam Sibuet, Claude E. Lambert, Roger Chesselet, Lucien Laubier Jan 1989

Density Of The Major Size Groups Of Benthic Fauna And Trophic Input In Deep Basins Of The Atlantic Ocean, Myriam Sibuet, Claude E. Lambert, Roger Chesselet, Lucien Laubier

Journal of Marine Research

Seven deep-sea areas were studied in the Atlantic Ocean. An intensive and comparable benthic sampling program was conducted during several deep-sea biology cruises with IFREMER research ships and mainly with the RV Jean Charcot, in the Norwegian Sea, the Bay of Biscay, the Porcupine Seabight, the Vema Fracture Zone, the Demerara abyssal plain, the Cape Verde Basin, the Angola and Cape basins near the Walvis Ridge. A synthesis of community structure data has been realized and the benthic fauna, quantitatively sampled, was separated into three main size categories (meiofauna, macrofauna sensu stricto and megafauna). Comparison of population densities in …

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Maximal Quantum Yield Of Photosynthesis In The Northwestern Sargasso Sea, J. S. Cleveland, M. J. Perry, D. A. Kiefer, M. C. Talbot Jan 1989

Maximal Quantum Yield Of Photosynthesis In The Northwestern Sargasso Sea, J. S. Cleveland, M. J. Perry, D. A. Kiefer, M. C. Talbot

Journal of Marine Research

The magnitude and variability of the maximal quantum yield of photosynthesis were examined in the northwestern Sargasso Sea in April 1985. Maximal quantum yield was calculated from light-limited photosynthetic rates and spectrally-weighted absorption coefficients. The absorption by total particulates collected on a glass fiber filter was partitioned into two components, one associated with living phytoplankton and one associated with other absorbing particles. Two types of maximal quantum yield were calculated: one from the absorption by total particulates and one from the absorption by the phytoplanktonic component alone. Maximal quantum yield calculated from absorption by total particulates was low [0.014 to …

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The Mode Site Revisited, William J. Schmitz Jr. Jan 1989

The Mode Site Revisited, William J. Schmitz Jr.

Journal of Marine Research

In the 1970's, an intense physical oceanographic effort was focused on the MODE Area (centered at 28N, 70W) to study mesoscale eddies and their effect on the larger-scale longer-term (or general) interior ocean circulation. At that time there was considerable discussion as to the typicality of these results. It has become clear that the time-dependent field is horizontally inhomogeneous; eddies have a geography related to the general circulation. In some areas, significant temporal inhomogeneity (nonstationarity) has been observed, but this issue has not yet been clarified for the MODE Area. Recently, a collective experiment to study the effect of fronts …

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Interaction Of Internal Waves And Mean Flow Observed Near A Coast, Pijush K. Kundu, Richard E. Thomson, Barbara M. Hickey, Paul H. Leblond Jan 1988

Interaction Of Internal Waves And Mean Flow Observed Near A Coast, Pijush K. Kundu, Richard E. Thomson, Barbara M. Hickey, Paul H. Leblond

Journal of Marine Research

Vortex stretching has been proposed as a possible mechanism by which internal waves can extract energy from the mean flow. Relationships between the slowly varying (ω < 0.25 cpd) and rapidly varying (0.13 cph < ω < 0.5 cph) components of the flow have been examined in a 4-month-long data set taken off the coast of British Columbia. The rapidly varying component of horizontal velocity generally rotates clockwise, and is in rough agreement with internal wave dynamics. It is horizontally incoherent within a distance of 10 km and is vertically coherent across the water column with a nearly 180° phase change. Scatter plots show that the wavefield is anisotropic, with the Reynolds stresses generally obeying uv < 0, vw < 0 and uw > 0, where (u, v, w) are the fluctuating velocity components in the (onshore, alongshore, upward) directions. Instances have been found in which time variations of uv and the mean horizontal shear rate Vx are negatively correlated, with an implied horizontal viscosity of VH ∼ (3 ± 2) × 105 cm2/s. No correlation of vw and the mean vertical shear V …

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A Numerical Model Study Of Internal Tides On The Australian Northwest Shelf, Peter D. Craig Jan 1988

A Numerical Model Study Of Internal Tides On The Australian Northwest Shelf, Peter D. Craig

Journal of Marine Research

Models of internal tides have been difficult to apply to realistic ocean situations because of restrictive assumptions on the form of either the bottom topography or the vertical density structure. A numerical model, based on the analytic model of Craig (1987a), is applied to a section through the Australian Northwest Shelf, and the results compared with data collected at the North Rankin location. The model simulates accurately the amplitude and phase structure of the internal tide. The predicted temperature and current amplitudes are within one-third of those observed, but the phase relationship between the temperature and surface tide is different …

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Cross-Phyletic Patterns Of Particle Selection By Deposit Feeders, Robert F. L. Self, Peter A. Jumars Jan 1988

Cross-Phyletic Patterns Of Particle Selection By Deposit Feeders, Robert F. L. Self, Peter A. Jumars

Journal of Marine Research

In controlled laboratory experiments using a wide array of exotic sediments of known characteristics (glass and plastic beads) we studied the mechanical, evolutionarily-fixed component of particle selection for ingestion in 5 surface and 6 subsurface deposit feeders, from 3 phyla (Annelida, Mollusca and Arthropoda). Three species were nonselective within all or part of the 3-324 μm particle size range tested, while the remaining 8 species exhibited unimodal patterns of size selection, peaking near 6 μm. In addition, the surface deposit feeders displayed a strong preference for particles of low specific gravity. Particle selection in tube construction by the polychaetes …

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On The Surface Drift Of The Southern Ocean, J. R. E. Lutjeharms, L. V. Shannon, L. J. Beekman Jan 1988

On The Surface Drift Of The Southern Ocean, J. R. E. Lutjeharms, L. V. Shannon, L. J. Beekman

Journal of Marine Research

Drift rates of the sea surface have been calculated for the South Atlantic and South Indian Ocean sectors of the Southern Ocean using drift cards and FGGE buoys. Drift patterns and drift rates, based on results from 40,000 plastic drift cards placed from 1978 to 1981, indicate significant equatorward surface exchange between the Southern Ocean and subtropical ocean gyres. Card drift rates increase with latitude up to the 40-45S zone. Average zonal drift rates lie between 10.3 cm/s and 16.4 cm/s. Zonally averaged drift rates of FGGE buoys are also at a maximum between 40 and 45S but are 15% …

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Buoyancy Driven Planetary Flows, A. Colin De Verdière Jan 1988

Buoyancy Driven Planetary Flows, A. Colin De Verdière

Journal of Marine Research

The large scale flow patterns driven by surface buoyancy flux are obtained as numerical solutions of the planetary geostrophic equations to which dissipation and diffusion have been appended. Within a cartesian β plane, square box geometry, the solution is made of gyres of the largest possible size with western and northern intensification, anticyclonic above the main thermocline, cyclonic below. Within regions of heat gain, the classical equilibrium between downward eddy diffusion and vertical upwelling is approximately observed in the main thermocline. As a consequence the abyssal circulation (southern interior and western boundary current) behave according to the early Stommel-Arons' ideas. …

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Recent Moored Current Meter And Sofar Float Observations In The Eastern Atlantic Near 32n, William J. Schmitz Jr., James F. Price, Philip L. Richardson Jan 1988

Recent Moored Current Meter And Sofar Float Observations In The Eastern Atlantic Near 32n, William J. Schmitz Jr., James F. Price, Philip L. Richardson

Journal of Marine Research

Basic flow statistics from the two-year deployment of a mooring in the vicinity of 32N and 24W are presented, along with intercomparisons between SOFAR float results concurrent with the first year of moored instrument data. Current-temperature meters were deployed in the main thermocline (∼500 m depth), in Mediterranean Water (1000–1100 m depth) along with the SOFAR floats, and at an abyssal (∼3000 m) level. The float and current meter averages over a common time interval are at least roughly the same, with eddy field intercomparisons being better than those for mean flow. Strong year-to-year variability in the time-averaged flow and …

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Microbial-Meiofaunal Interrelationships In Some Tropical Intertidal Sediments, Daniel M. Alongi Jan 1988

Microbial-Meiofaunal Interrelationships In Some Tropical Intertidal Sediments, Daniel M. Alongi

Journal of Marine Research

Interrelationships among microbial and meiofaunal communities were examined for one year at four intertidal mangrove and sandflat habitats in tropical northeastern Australia. None of the microbial and meiofaunal communities correlated with physical factors over the year as densities of most microbial and meiofaunal groups, bacterial productivity and specific growth rates (μ) of bacteria fluctuated significantly over time at each habitat with no distinct seasonality. However, over a tidal cycle, bacterial growth rates were significantly affected by tidal flooding and exposure on the sandflat; bacterial growth rates increased with increasing sediment temperatures upon exposure during daylight. Protozoan and meiofaunal …

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Cold-Seep Benthic Communities In The Japan Subduction Zones: Geological Control Of Community Development, Myriam Sibuet, S. Kim Juniper, Guy Pautot Jan 1988

Cold-Seep Benthic Communities In The Japan Subduction Zones: Geological Control Of Community Development, Myriam Sibuet, S. Kim Juniper, Guy Pautot

Journal of Marine Research

A large number of Calyptogena-dominated benthic communities, apparently chemosynthetically-based, were discovered at methane-rich pore-water seeps in the Japan subduction zones (3850–6000 m depth). Photographic and video surveys from four submersible dives were analyzed to study the influence of faulting, topography and substratum on exploitation of cold seeps by megafauna. Pore-water seepage occurred in a variety of geological settings, including subduction-erosion and accretionary prism formation, always in association with major faults which likely facilitated upward migration of fluids from a deep high-pressure zone. Sediment cover and manganese crusts on the seafloor appeared to block pore-water discharge, except where interrupted by …

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Phytoplankton Species Composition And Abundance In A Gulf Stream Warm Core Ring. I. Changes Over A Five Month Period, Richard W. Gould Jr., Greta A. Fryxell Jan 1988

Phytoplankton Species Composition And Abundance In A Gulf Stream Warm Core Ring. I. Changes Over A Five Month Period, Richard W. Gould Jr., Greta A. Fryxell

Journal of Marine Research

During the spring and summer of 1982, Gulf Stream warm core ring (WCR) 82B was sampled during four cruises from April to August to investigate the changes in the phytoplankton flora with time. Discrete water samples from 28 stations were collected for identification and enumeration of phytoplankton. The spring increase in WCR 828 occurred from late April to mid-May and was multiphasic; early periods were dominated by the diatoms Minidiscus trioculatus (4–5 μm diam.) and a small Thalassiosira, possibly T. bulbosa, while later periods were dominated by a small (2–3 μm) biflagellate. In June, another diatom …

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A Provisional Diagenetic Model For Ph In Anoxic Porewaters: Application To The Foam Site, Bernard P. Boudreau, Donald E. Canfield Jan 1988

A Provisional Diagenetic Model For Ph In Anoxic Porewaters: Application To The Foam Site, Bernard P. Boudreau, Donald E. Canfield

Journal of Marine Research

This paper presents a diffusion-advection-reaction model for the pH of anoxic porewaters in nonirrigated sediments. Because of the couplings demanded by the organic-matter decay reaction, various acid-base interconversions, dissolved-iron generation, and CaCO3 and FeS precipitation, the model does not consider H+ alone, but deals simultaneously with 17 dissolved species. The complex and largely unknown kinetics of some of the processes affecting these species have been approximated by simple ad hoc formulations. For this reason, the model must be considered provisional. We have also made extensive use of the local (partial) equilibrium assumption to circumvent the computational problems generated …

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Eddy-Wall Interactions, Doron Nof Jan 1988

Eddy-Wall Interactions, Doron Nof

Journal of Marine Research

A nonlinear one and a half-layer model is considered to examine the collision of isolated eddies with vertical walls. The round undisturbed eddies are allowed to have relatively large amplitudes; they are bounded by a free streamline beyond which the ocean is stagnant. The inviscid interaction is examined by, conceptually, “cutting” the eddies with a straight vertical wall. The resulting events are studied using a perturbation expansion in ε, the nondimensional penetration of the wall into the vortices, i.e., “weak” interactions are examined. Two class of eddies are considered. The first consists of linear quasi-geostrophic eddies (i.e., small amplitude …

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Mesoscale Heterogeneity Of The Wind-Driven Mixed Layer: Influence Of A Quasigeostrophic Flow, Patrice Klein, Bach Lien Hua Jan 1988

Mesoscale Heterogeneity Of The Wind-Driven Mixed Layer: Influence Of A Quasigeostrophic Flow, Patrice Klein, Bach Lien Hua

Journal of Marine Research

Weller (1982) and Kunze (1985) have shown that the presence of a geostrophic flow may be responsible for a large part of the observed mesoscale heterogeneity and intermittency of inertial oscillations. In this paper, the effects of this influence on the dynamics of the wind-driven mixed-layer (ML), in particular on entrainment and ML depth evolution, are analytically derived. A simple ML model including these effects is coupled with the quasigeostrophic numerical model of Hua and Haidvogel (1986) in order to investigate and characterize the specific effects of a quasigeostrophic flow on the ML spatial heterogeneity. Numerical results clearly show that …

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Field Assessment Of Sediment Trap Efficiency Under Varying Flow Conditions, Edward T. Baker, Hugh B. Milburn, David A. Tennant Jan 1988

Field Assessment Of Sediment Trap Efficiency Under Varying Flow Conditions, Edward T. Baker, Hugh B. Milburn, David A. Tennant

Journal of Marine Research

Knowledge of the collection efficiency of sediment traps, particularly under conditions of varying current speed, is presently more a matter of hope than confidence. We report here on a field experiment designed to determine, for a particular trap geometry, the effect of current speed and particle fall velocity on the collection efficiency of a moored trap relative to the presumably unbiased efficiency of an identical drifting trap. The experiment was performed in a deep estuarine tidal passage where a smoothly varying unidirectional flow and a spatially homogenous particle population mimicked laboratory flume conditions. A multiple-sample sediment trap integrated to a …

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Functional Response Of The Euphausiid Thysanoessa Raschii Grazing On Small Diatoms And Toxic Dinoflagellates, Sam Mcclatchie Jan 1988

Functional Response Of The Euphausiid Thysanoessa Raschii Grazing On Small Diatoms And Toxic Dinoflagellates, Sam Mcclatchie

Journal of Marine Research

The functional response of T. raschii feeding on monocultures of small phytoplankton at 0.4–14 μg pigment liter–1 was determined using a time-series method in a large volume flow-through grazing system. A model-free robust regression procedure aided by graphical and statistical methods was used to compare Ivlev, Michaelis-Menten, linear, Disk equation and Holling type III models. Ivlev, Michaelis-Menten and Disk equation models were less preferable to a linear model because their parameters were highly correlated and could not be uniquely determined, although they appear to fit the data graphically. Holling type III model did not fit the data. A …

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Response Of Small Motile Epifauna To Complexity Of Epiphytic Algae On Seagrass Blades, Margaret O. Hall, Susan S. Bell Jan 1988

Response Of Small Motile Epifauna To Complexity Of Epiphytic Algae On Seagrass Blades, Margaret O. Hall, Susan S. Bell

Journal of Marine Research

Field collections and experiments were performed to examine the relationship between the biomass of epiphytic algae (= habitat complexity) on Thalassia testudinum blades and the density of associated motile epifauna. Samples collected at Egmont Key, Florida indicated a significant positive association between the density of harpacticoid copepods, the most numerous taxon on seagrass blades, and biomass of the dominant epiphyte, Giffordia mitchelliae. Similar results were noted for nematodes, amphipods, and crustacean nauplii. Seagrass blades with large amounts of epiphytic algae are often older than blades with lesser amounts of algae, and have had a longer time to be colonized by …

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The Northern Limit Of Spawning By Atlantic Eels (Anguilla Spp.) In The Sargasso Sea In Relation To Thermal Fronts And Surface Water Masses, Robert C. Kleckner, James D. Mccleave Jan 1988

The Northern Limit Of Spawning By Atlantic Eels (Anguilla Spp.) In The Sargasso Sea In Relation To Thermal Fronts And Surface Water Masses, Robert C. Kleckner, James D. Mccleave

Journal of Marine Research

American and European eels (Anguilla rostrata and A. anguilla) spawn in a large poorly defined area east of the Bahamas between about longitude 50W and 75W in the Sargasso Sea. We use the distribution of tiny Anguilla larvae taken in ichthyoplankton collections and associated characterizations of hydrography to test two hypotheses concerning distribution of water masses and the northern limit of spawning by both species. Data are presented from four transects of closely spaced stations conducted during February and April 1983 which refute our hypothesis that a positive correlation exists between the distribution of the Subtropical Underwater and …

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The Comparison Of Macrobenthic Recolonization Patterns Near And Away From Crab Burrows On A Sublittoral Sand Flat, Simon F. Thrush Jan 1988

The Comparison Of Macrobenthic Recolonization Patterns Near And Away From Crab Burrows On A Sublittoral Sand Flat, Simon F. Thrush

Journal of Marine Research

This study assessed the influence of crab burrows (Macrophthalmus hirtipes) on localized patterns of macrobenthic colonization on a sand flat at 6 m depth in Otago Harbor, New Zealand. 150 m2 of surface sediments were artifically disturbed to simulate a storm and core samples were collected 2, 4, and 30 days later. At each time, samples were randomly collected near and away from crab burrows. A general pattern of high abundances away from burrows was apparent for most common taxa, number of taxa, number of individuals, and dominant polychaete feeding guilds. The differences in abundance near and …

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