Marine Biology Commons^™

Nutrient Provinces In The Sea: Concentration Ratios, Reaction Rate Ratios, And Ideal Covariation, Kent A. Fanning

Marine Science Faculty Publications

Global distributions of the ratios of the concentrations of nitrate + nitrite (= [N]) and phosphate (= [P]) are evaluated from Geochemical Ocean Sections Study (GEOSECS) and Transient Tracers in the Ocean (TTO) data sets. If large oceanic regions (or provinces) can be identified on the basis of constant [N]:[P] ratios, then the distribution equation for a reactive variable shows that the ratio of the net reaction rates involving N and P in each one is equal to its concentration ratio. Organisms within the interiors of the provinces would then be in balance with the ratios in which the nutrients …

Simulation Of The 1979 Spring Bloom In The Mid-Atlantic Bight: A Coupled Physical/Biological/Optical Model, Watson W. Gregg, John J. Walsh

Marine Science Faculty Publications

A coupled physical/biological/optical model was developed to investigate the causes of phytoplankton variability in the spring 1979 Mid-Atlantic Bight (MAB) as observed in Coastal Zone Color Scanner (CZCS) imagery, and to estimate the magnitude and variability of primary production. The model incorporated advection, mixing, sinking, growth as a function of light, temperature, and nutrient availability, and death as a function of ingestion. These variables were assumed to determine the large-scale, low-frequency variability of phytoplankton distributions the model also contained two phytoplankton groups, netplankton and nanoplankton, which differed in maximum growth rate, sinking rate, and specific light absorption. The model produced …

Concentration Of Microbial Populations From Aquatic Environments By Vortex Flow Filtration, Sunny C. Jiang, Jennifer M. Thurmond, Scott L. Pichard, John H. Paul

Marine Science Faculty Publications

Vortex Flow Filtration was used to concentrate particulate DNA, chlorophyll a and bacteria from freshwater, estuarine, coastal and oligotrophic marine environments. A Membrex Benchmark System with either a 100 kD or a 0.45-mu-m filter and a large-scale Pacesetter System with a 100 kD filter were used. The Benchmark System is ideal for processing 100 ml to 50 l of water, while the Pacesetter is designed for working with volumes from 20 l up to hundreds of liters. The Benchmark System with a 100 kD filter yielded an average recovery of 81.7, 83.3 and 80.5% respectively for particulate DNA, chlorophyll a …

The Phytoplankton Bloom In The Northwestern Arabian Sea During The Southwest Monsoon Of 1979, John C. Brock, Charles R. Mcclain, Mark E. Luther, William W. Hay

Marine Science Faculty Publications

The biological variability of the northwestern Arabian Sea during the 1979 southwest monsoon has been investigated by the synthesis of satellite ocean color remote sensing with analysis of in situ hydrographic and meteorological data sets and the results of wind-driven modeling of upper ocean circulation. The phytoplankton bloom in the northwestern Arabian Sea peaked during August-September, extended from the Oman coast to about 65-degrees-E, and lagged the development of open-sea upwelling by at least 1 month. In total, the pigment distributions, hydrographic data, and model results all suggest that the bloom was driven by spatially distinct upward nutrient fluxes to …

Reflectance Model For Quantifying Chlorophyll-A In The Presence Of Productivity Degradation Products, Kendall L. Carder, S. K. Hawes, K. A. Baker, R. C. Smith, R. G. Steward, B. G. Mitchell

Marine Science Faculty Publications

Marine colored dissolved organic matter (CDOM) (also gilvin or yellow substance) absorbs light at an exponentially decreasing rate as a function of wavelength. From 410 nm to about 640 nm, particulate phytoplankton degradation products including pheopigments, detritus, and bacteria have absorption curves that are similar in shape to that of CDOM. In coastal areas and areas downstream from upwelling regions, these constituents of seawater often absorb much more light than do living phytoplankton, leading to errors in satellite-derived chlorophyll estimates as high as 133%. Proposed NASA sensors for the 1990s will have spectral channels as low as 412 nm, permitting …

15N/14N And 13C/12C In Weddell Sea Invertebrates: Implications For Feeding Diversity, Greg H. Rau, Thomas L. Hopkins, Joseph J. Torres

Marine Science Faculty Publications

Biomass delta-C-13, delta-N-15, and C/N were measured for each of 29 taxa of pelagic invertebrates sampled from the Weddell Sea in March 1986. The delta-C-13 values of these animals ranged from -33.2 to -23.9 parts per thousand, and a significant negative logarithmic relationship was observed between these values and biomass C/N. This implies that the relative proportion of carbon-rich C-13-depleted lipid in these animals significantly influenced the delta-C-13 of their bulk biomass. No such relationship with C/N is evident with respect to biomass delta-N-15 where values ranged from -1.2 to +7.3 parts per thousand. This spread of values reflects a …

On The Seasonal Phytoplankton Concentration And Sea Surface Temperature Cycles Of The Gulf Of Mexico As Determined By Satellites, Frank E. Muller-Karger, John J. Walsh, Robert H. Evans, Mark B. Meyers

Marine Science Faculty Publications

Monthly climatologies of near‐surface phytoplankton pigment concentration and sea surface temperature (SST) were derived for the Gulf of Mexico from multiyear series of coastal zone color scanner (CZCS) (November 1978 to November 1985) and advanced very high resolution radiometer (AVHRR) (January 1983 to December 1987) images. We complement these series with SST from the comprehensive ocean‐atmosphere data set (1946–1987) and Climate Analysis Center (1982–1990), and hydrographic profile data from the NOAA National Oceanographic Data Center (1914–1985). The CZCS ocean color satellite data provide the first climatological time series of phytoplankton concentration for the region. The CZCS images show that seasonal …

On The Annual Cycle Of Equatorial Upwelling In The Central Atlantic-Ocean, Thomas J. Weingartner, Robert H. Weisberg

Marine Science Faculty Publications

The annual cycle of the upper ocean's vertical velocity component (w) on the equator at 28°W is examined by integrating the continuity equation using current meter data from the Seasonal Response of the Equatorial Atlantic Experiment. The annual cycle consists in part of an intense, but brief (∼1 month), upwelling season beginning with the onset of strong easterly wind stress in boreal spring. This upwelling is followed by weaker downwelling during the summer despite the persistence of strong easterly wind stress. The record-length averaged w profile shows that maximum upwelling (0.6 x 10^-3cm s^-1) …

A Description Of The Annual Cycle In Sea Surface Temperature And Upper Ocean Heat In The Equatorial Atlantic, Thomas J. Weingartner, Robert H. Weisberg

Marine Science Faculty Publications

Temperature and velocity time series, obtained by surface moorings during the Seasonal Response of the Equatorial Atlantic Experiment, are used to investigate the role of ocean dynamics upon the annual cycle of equatorial sea surface temperature (SST) and upper ocean heat. The annual cycle in SST is explained by different mechanisms, each operant at different phases of the cycle. The boreal springtime decrease in SST results from upwelling in response to the seasonal intensification of easterly wind stress. This upwelling causes the seasonal formation of the cold tongue along the equator in the central and eastern portions of the basin. …

A Linear Analysis Of Equatorial Atlantic Ocean Thermocline Variability, Robert H. Weisberg, T. Y. Tang

Marine Science Faculty Publications

Observed variations in the Atlantic Ocean's equatorial thermocline are compared at four locations with simultations using an analytical reduced-gravity model. The comparison shows the essential features of the seasonal wind-forced thermocline response to be accounted for by a linear superposition of equatorial long waves, evolving basinwide, tending to bring the zonal pressure gradient into balance with the wind stress. A frequency response function is derived whose properties provide a basis for discussing the large scale features of the equatorial Atlantic Ocean's seasonal cycle-for example, its evolution along the equator, the maximum upwelling region observed in the Gulf of Guinea and …

Aspects Of The Ecology Of The Mesopelagic Fish Gonostoma Elongatum (Gonostomatidae, Stomiiformes) In The Eastern Gulf Of Mexico, Thomas M. Lancraft, Thomas L. Hopkins, Joseph J. Torres

Marine Science Faculty Publications

Gonostoma elongatum is an important mesopelagic fish found throughout the world at subtropical-tropical latitudes. This study examined its distribution, abundance and life history in the eastern Gulf of Mexico. The species was a strong diel migrator, found from 25 to 325 m at night and from 425 to 725 m during the day with small fish occurring shallower than large fish. Numerical abundance and biomass were high, rivaling the dominant species of myctophids in the Gulf of Mexico. There no obvious seasonal fluctuations in population abundance. G. elongatum is a protandric hermaphrodite whose population breeds throughout the year and females …

Instability Waves In The Equatorial Atlantic Ocean, Robert H. Weisberg, T. J. Weingartner

Marine Science Faculty Publications

Evidence is presented for the generation of planetary waves by barotropic instability within the cyclonic shear region of the Atlantic Ocean's South Equatorial Current (SEC). Immediately following the springtime intensification of the southeast trade wind, which accelerates the SEC westward, a packet of waves with central periodicity of around 25 days is observed lasting for about three cycles. Independent wavenumber analyses on 1983 and 1984 data give newly identical zonal wavelengths and phase speed estimates of around 1100 km and −50 cm s⁻¹. The waves are anisotropic and spatially inhomogeneous with generation confined primarily to the mixed layer. …

Vertical Structure Of Low-Frequency Variability In The Eastern Equatorial Pacific Ocean, T. Y. Tang, Robert H. Weisberg, D. Halpern

Marine Science Faculty Publications

The vertical structure of low frequency velocity and temperature variability in the eastern equatorial Pacific Ocean is examined using surface and subsurface moored current meter data from 0°, 110°W between 20 and 3027 m depths over the period 30 March 1980 to 2 February 1981. Three methods of analysis are employed: vertical coherence, empirical orthogonal functions, and linear least-squares dynamical mode decompositions. Direct evidence is given for the existence of first baroclinic mode Kelvin waves in the east component of velocity and vertical displacement (estimated from temperature) in that the vertical displacement is coherent and in phase over the water …

Distribution And Molecular Weight Of Dissolved Dna In Subtropical Estuarine And Oceanic Environments, Mary F. Deflaun, John H. Paul, Wade H. Jeffrey

Marine Science Faculty Publications

Dissolved DNA and a series of microbial biomass and activity parameters were measured in offshore, coastal, estuarine and coral reef environments of the southeast Gulf of Mexico. Oceanic concentrations of dissolved DNA ranged from 0.2 to 19 μg 1^-1 and decreased as a function of distance from shore and depth in the water column. Dissolved DNA concentrations were greater than half the particulate DNA content in offshore environments (̄x̄ = 63 ± 45 %) but were a smaller percentage of particulate DNA in nearshore and estuarine environments (̄x̄ = 35 ± 21 %). Dissolved DNA correlated better with bacterial …

Velocity And Temperature Observations During The Seasonal Response Of The Equatorial Atlantic Experiment At 0 Degrees, 28 Degrees W, Robert H. Weisberg, J. H. Hickman, T. Y. Tang, T. J. Weingartner

Marine Science Faculty Publications

Continuous 2.7‐year time series of upper ocean currents and temperature at 0°, 28°W collected during the Seasonal Response of the Equatorial Atlantic Experiment are presented. The thermocline underwent distinctive annual cycles in response to forcing by the surface wind stress, and the core of the Equatorial Undercurrent tracked the thermocline. While the vertical position of the thermocline and the undercurrent appear to be simply related, the transport of the undercurrent did not show a replicating annual cycle, and the speed at the undercurrent core remained relatively constant. Near surface flow when averaged over the 2.7 years was not statistically different …

M2 Tidal Currents In The Eastern Equatorial Pacific Ocean, Robert H. Weisberg, D. Halpern, T. Y. Tang, S. M. Hwang

Marine Science Faculty Publications

Current meter measurements recorded over the water column at 10 depths ranging from 20 m to 3027 m using surface and subsurface moorings near 0°, 110°W are analyzed for the M₂ tidal current over a 10‐month sampling interval. A kinematical description is given by month and depth, followed by a decomposition into a barotropic mode and three baroclinic modes. The barotropic tide was dominant, and its hodograph was stable over the 10 months sampled. The baroclinic tide was random, isotropic, and without mode preference.

Further Studies On The Response Of The Equatorial Thermocline In The Atlantic Ocean To The Seasonally Varying Trade Winds, Robert H. Weisberg, T. Y. Tang

Marine Science Faculty Publications

Upper ocean temperature data obtained during the Seasonal Response of the Equatorial Atlantic experiment and the Francais Ocean et Climat dans l'Atlantique Equatorial program are used to describe the variations of the thermocline observed along the equator from February 1983 to September 1984. In response to rapid seasonal changes in zonal wind stress, the thermocline underwent sequences of upwelling followed by downwelling or conversely, depending upon whether the winds were intensifying or relaxing. These sequences increased systematically in magnitude and duration to the east. Both the sequential behavior and its zonal inhomogeneity represent departures from the slowly varying and in-phase …

Elevated Levels Of Microbial Activity In The Coral Surface Microlayer, John H. Paul, Mary F. Deflaun, Wade H. Jeffrey

Marine Science Faculty Publications

No abstract provided.

Stable Hydrogen And Carbon Isotopic Compositions Of Biogenic Methanes, Roger Allen Burke Jr.

USF Tampa Graduate Theses and Dissertations

Stable hydrogen and carbon isotopic compositions of biogenic methanes collected from the sediments of several deep-sea, nearshore marine-estuarine, and freshwater environments were determined. The isotopic compositions of methane samples from eight different DSDP Sites (mean σD-CH₄ = -185⁰>/∞, std. dev. = 7⁰>/∞, n = 75; mean σ¹³C-CH₄ = -71.3⁰/∞, std. dev. = 6.3⁰/∞, n = 44) are generally typical of methane formed via C0₂ reduction in deep-sea sediments.

Methane collected from several freshwater environments was D-depleted (mean σD-CH₄ = -300⁰>/∞ , std. dev. = …

Uptake Of Zn65 And Mn54 Into Body Tissues And Renal Granules By The Southern Quahog, Mercenaria Campechiensis, William Lynn Miller Jr.

USF Tampa Graduate Theses and Dissertations

A study was conducted to examine the influence of elevated inorganic phosphate and trace metal concentrations on the uptake and distribution of Zn⁶⁵ and Mn⁵⁴ into the body tissue and phosphoritic renal concretions of a subtropical estuarine bivalve, Mercenaria campechiensis. Chronological sampling of gills, mantle, adductor muscle, viscera, kidneys, and renal granules using gamma ray spectrometry allowed examination of both tissue distribution and accumulation patterns over time. The kidney was the principal site of Mn⁵⁴ accumulation whereas Zn⁶⁵ was concentrated in both the gill and the kidney. The gill initially accumulated zn65 three times faster …

On The Response Of The Equatorial Thermocline In The Atlantic Ocean To The Seasonally Varying Trade Winds, Robert H. Weisberg, T. Y. Tang

Marine Science Faculty Publications

Measurements made during the Seasonal Response of the Equatorial Atlantic experiment in 1983, when the easterly trade winds near the equator ceased and then intensified as part of their annual cycle, show a sequence of events leading to an adjusted thermocline. Both the duration and extent of the downwelling and upwelling associated with the adjustment process were zonally inhomogeneous along the equator. An analytical reduced gravity model was driven by a hierarchy of easterly wind stress forcing functions representative of the Atlantic to compare the integral nature of the forced long-wave responses with the observations. Qualitative agreement was found with …

Equatorial Atlantic Velocity And Temperature Observations: February-November 1981, Robert H. Weisberg

Marine Science Faculty Publications

Upper ocean velocity and temperature measurements were obtained in the central equatorial Atlantic using surface moored current meters from February to November 1981. Distinct seasonal variations were observed in the zonal momentum and temperature on the equator of both the surface South Equatorial Current (SEC) and the subsurface Equatorial Undercurrent (EUC). After initially intensifying during boreal spring the SEC halted abruptly in early summer and the signature associated with this change progressed. At the observational depth of 100 m both speed and temperature increased during early summer with eastward progression and then decreased in fall. Higher frequency motions were also …

Factors Influencing The Degree Of Saturation Of The Surface And Intermediate Waters Of The North Pacific Ocean With Respect To Aragonite, Richard A. Feely, Robert H. Byrne, Peter R. Betzer, James F. Gendron, James G. Acker

Marine Science Faculty Publications

New carbonate chemistry data obtained during a 1982 cruise have been combined with earlier GE‐OSECS and INDOPAC data to determine the degree of aragonite saturation of surface and intermediate waters of the North Pacific. Large gradients in saturation state occur in the region of the Subarctic Front in the north‐south direction and across the Subtropical Gyre in the east‐west direction. These gradients are primarily due to the extensive mixing that occurs in the intermediate waters of the western North Pacific. The major variations in saturation state were primarily related to the carbonate ion concentration, which, in turn, is primarily a …

Trophodynamics Of The Fish Valenciennellus Tripunctulatus. I. Vertical Distribution, Diet And Feeding Chronology, Thomas L. Hopkins, Ronald C. Baird

Marine Science Faculty Publications

The adult and juvenile life stages of the small (~25mm) zooplanktivorous mesopelagic fish Valenciennellus tripunctulatus (Esmark) are found at depths of 200-600m throughout the diel period. Average population density was estimated to be 5 fish (104m³)^-1 and the maximum density recorded was 11 fish (104m³)^-1. Copepods constituted ~95% of all food items identified and Pleuromamma was the principal forage genus, contributing 31% and 56% to numbers and biomass of food items, respectively. Ontogenetic changes in diet were observed, the percentage of larger copepods increasing in the diet with increasing fish size. Food items …

Trophodynamics Of The Fish Valenciennellus Tripunctulatus. Ii. Selectivity, Grazing Rates And Resource Utilization, R. C. Baird, Thomas L. Hopkins

Marine Science Faculty Publications

Various patterns of resource utilization in the feeding strategy of Valenciennellus tripunctulatus, a small mesopelagic fish of tropical-subtropical oceans, were explored. Ivlev electivity indices suggest that copepods in general and the genus Pleuromamma in particular are being actively selected. Prey-size selection was apparent and strong negative indices were calculated for all plankton smaller than 1 mm. Non-crustacean prey in all size classes also gave negative indices. Strong positive indices were indicated for prey size classes greater than 2 mm. A model was developed to estimate grazing rates and efficiencies which is linearly influenced by swimming speed and plankton abundance, …

Trophodynamics Of The Fish Valenciennellus Tripunctulatus Iii Energetics, Resources And Feeding Strategy, Ronald C. Baird, Thomas L. Hopkins

Marine Science Faculty Publications

A model was constructed which relates energy in diet to metabolic requirements for the mesopelagic zooplanktivore fish Valenciennellus tripunctulatus. Linear and Von Bertalanffy growth models were used to explore the energetic consequences of a number of feasible age/growth strategies. Maxlmum efficiencies were obtained with linear growth to about 30 mm in 1 y. Efficiencies declined rapidly for slower growth strategies. It was hypothesized that an 'annual' life history strategy was optimum based on energetic considerations. Copepod prey in the 1-2 mm size class were an order of magnitude more abundant and over 4 times higher in caloric content than …

Reproductive Variability In Lytechinus Variegatus (Echinodermata: Echinoidea) From Different Habitats In A Florida West Coast Estuary, Robert G. Ernest

USF Tampa Graduate Theses and Dissertations

Lytechinus variegatus (Lamarck, 1916) is a sea urchin inhabiting shallow sub-littoral environments from Beaufort, North Carolina to southern Brazil. Although it has been collected extensively for embryological material in the southeastern United States (Harvey, 1956; Brookbank, 1968). there have been relatively few studies of its reproduction. Gonad indices were used to follow its annual reproductive cycle at Bermuda and Miami (Moore et al., 1963; Moore and Lopez, 1972), while elsewhere, only observations of spawn- ing have been reported (Boolootian, 1966).

In the Anclote estuary near Tarpon Springs, Florida, Lytechinus is the most conspicuous of the macroepibenthic invertebrates, and where requisite …