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Showing papers in "Oceanographic Literature Review in 1995"



Journal Article
TL;DR: In this paper, complete optical absorption and fluorescence spectra were collected for a diverse suite of 0.2-μm-filtered marine, riverine, and estuarine waters, as well as for colored dissolved organic matter (CDOM) isolated from several of these waters by solid phase C 18 extraction.
Abstract: Complete optical absorption and fluorescence spectra were collected for a diverse suite of 0.2-μm-filtered marine, riverine, and estuarine waters, as well as for colored dissolved organic matter (CDOM) isolated from several of these waters by solid-phase C 18 extraction. Absorption and fluorescence parameters for these samples are reported. For surface waters, variations in the fluorescence quantum yields obtained with 355- and 337-nm excitation fell within a narrow window (< 2.5-fold variation about the mean values), demonstrating that fluorescence measurements can be used to determine absorption coefficients of CDOM in the ultraviolet region with reasonably good accuracy. Methods for predicting absorption coefficients and line shapes from the fluorescence data are introduced and tested. The absorption and fluorescence spectra of CDOM extracted from some seawaters differed significantly from those of the original waters, demonstrating that material isolated by hydrophobic adsorption is not necessarily representative of the suite of colored organic matter present in aquatic systems. These results clearly illustrate that great care must be taken when extracted material is used to infer the optical properties of natural waters

678 citations


Journal Article
TL;DR: In this article, a new parameterization of oceanic boundary layer mixing is developed to accommodate some of this physics, including a scheme for determining the boundary layer depth h, where the turbulent contribution to the vertical shear of a bulk Richardson number is parameterized.
Abstract: If model parameterizations of unresolved physics, such as the variety of upper ocean mixing processes, are to hold over the large range of time and space scales of importance to climate, they must be strongly physically based. Observations, theories, and models of oceanic vertical mixing are surveyed. Two distinct regimes are identified: ocean mixing in the boundary layer near the surface under a variety of surface forcing conditions (stabilizing, destabilizing, and wind driven), and mixing in the ocean interior due to internal waves, shear instability, and double diffusion (arising from the different molecular diffusion rates of heat and salt). Mixing schemes commonly applied to the upper ocean are shown not to contain some potentially important boundary layer physics. Therefore a new parameterization of oceanic boundary layer mixing is developed to accommodate some of this physics. It includes a scheme for determining the boundary layer depth h, where the turbulent contribution to the vertical shear of a bulk Richardson number is parameterized. Expressions for diffusivity and nonlocal transport throughout the boundary layer are given. The diffusivity is formulated to agree with similarity theory of turbulence in the surface layer and is subject to the conditions that both it and its vertical gradient match the interior values at h. This nonlocal “K profile parameterization” (KPP) is then verified and compared to alternatives, including its atmospheric counterparts. Its most important feature is shown to be the capability of the boundary layer to penetrate well into a stable thermocline in both convective and wind-driven situations. The diffusivities of the aforementioned three interior mixing processes are modeled as constants, functions of a gradient Richardson number (a measure of the relative importance of stratification to destabilizing shear), and functions of the double-diffusion density ratio, Rρ. Oceanic simulations of convective penetration, wind deepening, and diurnal cycling are used to determine appropriate values for various model parameters as weak functions of vertical resolution. Annual cycle simulations at ocean weather station Papa for 1961 and 1969–1974 are used to test the complete suite of parameterizations. Model and observed temperatures at all depths are shown to agree very well into September, after which systematic advective cooling in the ocean produces expected differences. It is argued that this cooling and a steady salt advection into the model are needed to balance the net annual surface heating and freshwater input. With these advections, good multiyear simulations of temperature and salinity can be achieved. These results and KPP simulations of the diurnal cycle at the Long-Term Upper Ocean Study (LOTUS) site are compared with the results of other models. It is demonstrated that the KPP model exchanges properties between the mixed layer and thermocline in a manner consistent with observations, and at least as well or better than alternatives.

409 citations


Journal Article
TL;DR: In this article, the mean flow and turbulence in a wave flume for a spilling breaker and a plunging breaker were studied, and the results indicated that there are fundamental differences in the dynamics of turbulence between spilling and plunging breakers, which can be related to the processes of wave breaking and turbulence production.
Abstract: Undertow and turbulence in the surf zone have been studied in a wave flume for a spilling breaker and a plunging breaker. Fluid velocities across a 1 on 35 sloped false bottom were measured using a fiber-optic laser-Doppler anemometer, and wave decay and set-up were measured using a capacitance wave gage. The characteristics of mean flow and turbulence in spilling versus plunging breakers were studied. The mean flow is the organized wave-induced flow defined as the phase average of the instantaneous velocity, while the turbulence is taken as the deviations from the phase average. It was found that under the plunging breaker turbulence levels are much higher and vertical variations of undertow and turbulence intensity are much smaller in comparison with the spilling breaker. It was also found that turbulent kinetic energy is transported seaward under the spilling breaker and landward under the plunging breaker by the mean flow. The study indicates that there are fundamental differences in the dynamics of turbulence between spilling and plunging breakers, which can be related to the processes of wave breaking and turbulence production. It is suggested that the types of beach profile produced by storm and swell waves may be the results of different relationships between mean flow and turbulence in these waves.

363 citations


Journal Article
TL;DR: The role of water in the evolution of planetary atmospheres is discussed in this paper, where models of ocean and atmospheric and oceanic data and models of the coupled system are used to perform systematic analyses of hydrological processes and their role in system interaction.
Abstract: Earth is unique among the planets of the solar system in possessing a full hydrological cycle. The role of water in the evolution of planetary atmospheres is discussed. As the atmospheres of the planets developed and modified the early climates of the planets, only the climate trajectory of Earth intercepted the water phase transitions near the triplet point of water, thus allowing the full gamut of water forms to coexist. As a result, transitions between the water phases pervade the entire system and probably are responsible for the creation of a unique climate state. The interactions between the components of the climate system are enriched by the nonlinearity of the water phase transitions. The nonlinear character of the phase transitions of water suggests that the climate should be particularly sensitive to hydrological processes, especially in the tropics. Signatures of the nonlinearity are found in both the structures of the oceans and the atmosphere. Models of the ocean and atmospheric and oceanic data and models of the coupled system are used to perform systematic analyses of hydrological processes and their role in system interaction. The analysis is extended to consider the role of hydrological processes in the basic dynamics and thermodynamicsmore » of oceanic and atmospheric systems. The role hydrological processes play in determining the scale of the major atmospheric circulation patterns is investigated. Explanations are offered as to why large-scale convection in the tropical atmosphere is constrained to lie within the 28{degrees}C sea surface temperature contour and how hydrological processes are involved in interannual climate variability. The relative roles of thermal and haline forcing of the oceanic thermohaline circulation are discussed. Hydrological processes are considered in a global context by the development of a conceptual model of a simple planetary system. 94 refs., 38 figs., 5 tabs.« less

297 citations


Journal Article
TL;DR: Geomorphology and sedimentology of estuaries - an introduction, GME Perillo definitions and geomorphologic classifications as mentioned in this paper, an introduction to the geomorphological and sedimentological classification of the seafloor of mangroves.
Abstract: Geomorphology and sedimentology of estuaries - an introduction, GME Perillo definitions and geomorphologic classifications of estuaries, GME Perillo sedimentary systems of coastal-plain estuaries, H Bokuniewicz geomorphology and sedimentology of rias, P Castaing and A Guilcher sedimentology and geomorphology of fjords, JPM Syvitski and J Shaw tide-dominated estuaries and tidal rivers, JT Wells delta front estuaries, BS Hart structural estuaries, M Pinto Quivira coastal lagoons, FI Isla siliciclastic tidal flats, CL Amos salt marshes, JL Luternauer et al geomorphology and sedimentology of mangroves, PGEF Augustinus estuarine dunes and bars, RW Dalrymple and RN Rhodes sediment transport processes in estuaries, KR Dyer

285 citations



Journal Article
TL;DR: The regional tectonic stress field, basin development, and crustal deformation of the NE Japan arc in the interval between 32 Ma to the Quaternary can be synthesized based on dike, vein, and fault orientation data, as well as on the compilation of the regional geology.
Abstract: The regional tectonic stress field, basin development, and crustal deformation of the NE Japan arc in the interval between 32 Ma to the Quaternary can be synthesized based on dike, vein, and fault orientation data, as well as on the compilation of the regional geology. An extensional stress field became prevalent from 32 Ma, and major normal faulting started at 25–20 Ma, which resulted from back arc rifting. Normal faulting, trending nearly parallel to the arc, propagated from the present Japan Sea coast to the forearc side, following the trenchward migration of the main volcanic field. From 20 to 15 Ma, normal faults with an oblique trend to the arc developed due to the counterclockwise rotation of NE Japan. The rapid clockwise rotation of SW Japan since 16 Ma produced a NW-SE directed transtensional stress regime in the NE Japan arc. Due to crustal stretching associated with this pull-apart movement, the back arc side of the NE Japan arc subsided rapidly to middle bathyal environments. After the termination of the opening of the Japan Sea at about 14 Ma, a neutral stress regime prevailed, which included phases of both weak extension and compression. Lithospheric cooling eventually led to thermal subsidence of the back arc region, and igneous underplating caused uplift of the axial zone of the volcanic arc. The increase in velocity of the westward motion of the Pacific plate at around 4 Ma produced strong compression across the arc, reactivating most of the Miocene normal faults, and uplifting the volcanic arc. The greatest crustal shortening occurred in areas that were stretched the most in the Miocene within the volcanic arc, which implies tectonic inversion.

271 citations


Journal Article
TL;DR: In this article, polycyclic aromatic hydrocarbons (PAH) concentrations were measured in sediments and porewaters isolated from three cores from Boston Harbor, MA, and they were significantly lower than the concentrations predicted by two-and three-phase equilibrium partitioning models.
Abstract: Polycyclic aromatic hydrocarbon (PAH) concentrations were measured in sediments and porewaters isolated from three cores from Boston Harbor, MA. Measured porewater PAH concentrations were significantly lower than the concentrations predicted by two- and three-phase equilibrium partitioning models. We hypothesize that only a fraction of the measured sediment PAH concentrations was available to partition rapidly into sediment porewaters.

264 citations


Book ChapterDOI
TL;DR: This article showed that passive uptake of the lipophilic complexes (primarily HgCl2 and CH3HgCl) results in high concentrations of both inorganic and MMHg in phytoplankton.
Abstract: The factors controlling the accumulation of mercury in fish are poorly understood. The oil invoked lipid solubility of MMHg is an inadequate explanation because inorganic Hg complexes, which are not bioaccumulated, are as lipid soluble as their MMHg analogs and, unlike other hydrophobic compounds, MMHg in fish resides in protein rather than fat tissue. We show that passive uptake of the lipophilic complexes (primarily HgCl2 and CH3HgCl) results in high concentrations of both inorganic and MMHg in phytoplankton. However, differences in partitioning within phytoplankton cells between inorganic mercury — which is principally membrane bound — and MMHg — which accumulates in the cytoplasm — lead to a greater assimilation of MMHg during zooplankton grazing. Most of the discrimination between inorganic and MMHg thus occurs during trophic transfer while the major enrichment factor is between water and phytoplankton. As a result, MMHg concentrations in fish are ultimately determined by water chemistry which controls MMHg speciation and uptake at the base of the food chain.

237 citations


Journal Article
TL;DR: It is argued, however, that the microbial food web during summer stratification has a net accumulation of dissolved organic carbon (DOG) and DOP, and limited data available suggest a high DOC:DOP value which would make downwards transport of DOC with winter deep water formation a potentially effective mechanism in C sequestration from the atmosphere.
Abstract: In light of evidence suggesting that both phytoplankton and bacteria in the Mediterranean Sea are limited by the availability of phosphorus rather than of nitrogen, and that most of the P in the photic zone during summer stratification exists as dissolved organic compounds (DOP), we address the question of how these observations may interact with the 'biological pump' transporting carbon to deep waters. From theoretical considerations, the C storage via sinking particles should function better in a P- than in an N-limited system. It is argued, however, that the microbial food web during summer stratification has a net accumulation of dissolved organic carbon (DOG) and DOP. The limited data available suggest a high DOC:DOP value which would make downwards transport of DOC with winter deep water formation a potentially effective mechanism in C sequestration from the atmosphere. Part of the DOC accumulating in the photic zone appears to be readily biodegradable. This is in conflict with a simple model of phytoplankton-bacterial competition for phosphate since phytoplankton, as an inferior competitor, would be expected to be reduced in biomass until autochthonous production of organic C falls to a level where bacteria become C-limited. The conflict is resolved by including microzooplankton grazing as a controlling factor of bacterial biomass.

Journal Article
TL;DR: Closing the cycle Global Transfer of Phosphorus in Fertilizer Materials PHosphorus Fertility Management in Agroecosystems Heavy Metal and Radionuclide Contaminants Rehabilitation of Anthropic Savannah Phosphorous Transfer from Terrestrial to Aquatic Ecosystems Riverine Transport and Transformation of PHPOSorus Nutrient Limitation of Phytoplankton and Eutrophication of Estuarine and Marine Waters as discussed by the authors
Abstract: Closing the Cycle Global Transfer of Phosphorus in Fertilizer Materials Phosphorus Fertility Management in Agroecosystems Heavy Metal and Radionuclide Contaminants Rehabilitation of Anthropic Savannah Phosphorus Transfer from Terrestrial to Aquatic Ecosystems Riverine Transport and Transformation of Phosphorus Nutrient Limitation of Phytoplankton and Eutrophication of Estuarine and Marine Waters.


Journal Article
TL;DR: The seasonal growth pattern of the seagrass Posidonia oceanica (L.) Delile was examined in 5 meadows in NE Spain to assess the relative importance of large-scale versus local factors in controbng the seasonal patterns observed as discussed by the authors.
Abstract: The seasonal growth pattern of the seagrass Posidonia oceanica (L.) Delile was examined in 5 meadows in NE Spain to assess the relative importance of large-scale versus local factors in controbng the seasonal patterns observed. Large-scale seasonal forcing, resulting from changes in light and temperature associated with the solar cycle, was assessed from the coherence of seasonal growth palterns among the meadows and accounted for 46 and 43% of variability in shoot size and growth, respectively. The local component of seasonality, which results from local variation in environmental variables (e.g. nutrients, dissolved inorganic carbon, redox potential) was assessed as the differences in the annual time course of shoot size and growth among the meadows, and accounted for 9 and 12% of the variability, respectively. These results support the contention that seagrass seasonality is primarily controlled by the solar cycle, and secondarily by seasonal changes in the environment which are at leas1 in part caused by the temporal variability of seagrass growth. This indirect link between light and temperature and local conditions needs to be taken into account to interpret correlations between such variables and seagrass growth.

Journal Article
TL;DR: The results demonstrate that spatial patterning of the habitat, independent of structural characteristics of the seagrass, can alter rates of predation on segrass inhabitants and that very patchy seagRass beds may provide habitats where transfer of secondary production to higher trophic levels is great.
Abstract: Landscape ecology includes the study of the effects of spatial patterning of habitats on biotic and abiotic processes. Seagrass beds occur in a variety of spatial configurations providing a model system to test how spatial patterning of habitats influences ecological processes. We established four replicate plots over very patchy (22% cover), patchy (70% cover), and continuous (97% cover) seagrass beds so that each plot contained approximately 100 m 2 of vegetated bottom. Fifty individually marked scallops were placed within the seagrass in each plot and their survivorship monitored over three replicate 24-h periods, and growth and survival monitored over an additional four-week period. There was no pattern in survivorship with differences in habitat configuration over the first three 24-h of the experiment. By four weeks, more scallops were lost to predation in the very patchy seagrass beds than in the patchy or continuous beds. There was a non-significant trend for increased growth of juvenile scallops with increased patchiness of the seagrass habitat. Vegetation characteristics such as shoot density, biomass, and blade length, which have been shown to affect survival of seagrass-associated invertebrates, were not significantly different among seagrass beds with different spatial configurations. Our results demonstrate that spatial patterning of the habitat, independent of structural characteristics of the seagrass, can alter rates of predation on seagrass inhabitants. This implies that habitat utilization and/or foraging strategies of predators change with the spatial patterning of the vegetation and that very patchy seagrass beds may provide habitats where transfer of secondary production to higher trophic levels is great

Journal Article
TL;DR: In this paper, the behavior of a multiple bar system in the nearshore zone of the island of Terschelling, the Netherlands, was investigated on the time scale of years using a data set of soundings.
Abstract: The behaviour of a multiple bar system in the nearshore zone of the island of Terschelling, the Netherlands, is investigated on the time scale of years using a data set of soundings. The data set covers the period from 1965 to 1993. The behaviour is analysed in terms of bar crest position and in terms of morphometric parameters, such as bar crest depth, height, width, and volume. Two or three breaker bars are permanently present in the study area. Each individual bar passes through three stages during its existence: (1) generation close to the shore, (2) seaward migration and (3) degeneration at the outer margin of the nearshore bar zone. The key factor controlling the behaviour of the inner bars is the crest depth of the outer bar. Three different couplings between the behaviour of the individual bars have been observed: (1) bar stage changes due to the degeneration of the outer bar, (2) prevention of the transition of an inner bar from the first to the second stage, caused by the appearance from alongshore of a new outer bar having a small crest depth and (3) difference in mean annual seaward migration rate caused by the possible presence of a more seaward positioned bar. It is hypothesized that the crest depth of the outer bar governs the relative importance of processes inducing shoreward and seaward migration in the inner nearshore bar zone and therefore controls the behaviour of the nearshore bar zone on the time scale of years.


Journal Article
TL;DR: In this article, the authors proposed a power model for estimating the feeding of fish in the wild, which is more accurate than the linear model of the Gastric Evacuation Model (GEM).
Abstract: 1. The foundation of the method for estimating feeding using gastric evacuation studies lies in the input = output rule. More complex models may have specialized uses, for example where there are marked short-term fluctuations in feeding. 2. There is a lack of standardization in experimental design, data analysis and terminology which hampers comparative studies of gastric evacuation and often leads to unnecessary confusion. 3. Most gastric evacuation models are based on single-meal experimental designs, even though it is well documented that a second meal can alter the evacuation pattern of the first meal. 4. Assessment of the best-fitting gastric evacuation model is usually arrived at by choosing the model that gives the highest r2. This does not necessarily indicate whether one model offers significant improvements over another, and it does not indicate whether the resulting feeding model can be applied in practice to give improved estimates of feeding for natural fish populations as a whole. 5. Censoring and other biases can distort the results of gastric evacuation experiments so that the observed model of gastric evacuation becomes increasingly misrepresentative of the functional gastric evacuation relationship. Most published studies have not attempted to accommodate for these effects and are likely to overemphasize the curvature of evacuation and under-estimate evacuation at low levels of stomach fullness. 6. The acceptance of a power model over a linear model results in the need for accurate estimates of the mean and variance of stomach contents of fish in the wild. There do not appear to have been any attempts to determine whether this can be achieved with sufficient accuracy for the power model to give more reliable estimates of feeding than the simpler linear model. 7. There are many opportunities for bias in estimating the stomach contents of fish in the field, many of which do not appear to have been given a great deal of attention in most studies. 8. One of the biggest sources of potential error in the process of estimating feeding can be generated by errors and biases in the estimate of population size. Errors in the estimate of population size directly influence the estimate of total consumption of fish populations and, in turn, the size of future populations. 9. There is a need for models based on feeding patterns more akin to those occurring naturally, rather than on experimental designs based almost entirely on single meals containing only one type of prey.

Journal Article
TL;DR: The hypothesis that male reproductive success in this species is principally determined by dominance rank, which, in turn, is affected by male size is supported, but it is suggested that large size is just one of a number of important factors that affect the outcome of male intra-sexual competition and hence, reproductive success.
Abstract: Abstract Abstract. The relationship between size, dominance and copulatory success was investigated in male northern elephant seals to determine the importance of size in male intra-sexual competition for mates. The study was conducted over four breeding seasons at the Ano Nuevo rookery in central California. Mass was estimated using a photogrammetrical technique in three seasons and measured directly in one. Copulatory success was positively correlated with size (mass and length). This correlation was mediated through the positive effect of size on dominance rank; variation in arrival mass, for example, accounted for 29-44% of the variation in dominance. Copulatory success was positively correlated with dominance rank for mid- to high-ranking males, but not for low-ranking males, which obtained few copulations. Copulatory success was not significantly correlated with size when the effect of dominance was removed statistically. These results support the hypothesis that male reproductive success in this species is principally determined by dominance rank, which, in turn, is affected by male size. However, they also suggest that large size is just one of a number of important factors that affect the outcome of male intra-sexual competition and hence, reproductive success.


Journal Article
TL;DR: High-resolution studies of North Atlantic deep sea cores demonstrate that prominent increases in iceberg calving recurred at intervals of 2000 to 3000 years, much more frequently than the 7000-to 10,000-year pacing of massive ice discharges associated with Heinrich events.
Abstract: High-resolution studies of North Atlantic deep sea cores demonstrate that prominent increases in iceberg calving recurred at intervals of 2000 to 3000 years, much more frequently than the 7000-to 10,000-year pacing of massive ice discharges associated with Heinrich events. The calving cycles correlate with warm-cold oscillations, called Dansgaard-Oeschger events, in Greenland ice cores. Each cycle records synchronous discharges of ice from different sources, and the cycles are decoupled from sea-surface temperatures. These findings point to a mechanism operating within the atmosphere that caused rapid oscillations in air temperatures above Greenland and in calving from more than one ice sheet.

Journal Article
TL;DR: In this article, a detailed depth-profile of Yttrium in seawater together with the lanthanides in the North Pacific Ocean is presented, showing that the concentrations of Y(III) range 70-290 pmol/kg and show the "nutrient-like" profile best resembling that of Ho(III), amongst the other rare earth elements.
Abstract: Yttrium has long been recognized as an ekalanthanide, because of its chemical contiguity relative to the chemistries of rare earth elements which are, in recent years, intensively utilized for elucidation of metal scavenging processes in the ocean. Here, we present the first detailed depth-profile of Y(III) in seawater together with the lanthanides in the North Pacific Ocean. The concentrations of Y(III) range 70–290 pmol/kg and show the “nutrient-like” profile best resembling that of Ho(III) amongst the other rare earth elements. The results agree well with an expectation based on the similarity in their ionic radii and hence stability constants of complexation with carbonate ions. Yet the Ho(III)/Y(III;) ratios in seawater systematically increase with depth, suggesting that Y and Ho are fractionated during scavenging by natural marine particulates. This is likely to result from the different complexation behavior in that Y(III) is more weakly complexed than Ho(III) with soft organic ligands on the surface of particulate matter during scavenging in the surface water but, once released into seawater in the deep sea, Y(III) is complexed with carbonate ions equally or stronger than Ho. The pattern of deep water enrichment in the lanthanide series appears to be consistent with the recent observation of partitioning between suspended particles and seawater. Our precise measurements also indicated that Pr and Tb best resemble Nd and Dy, respectively in their oceanic behavior, whereas Ho and Tm are intermediate between their neighboring rare earth elements.


Journal Article
TL;DR: In this article, the spectral responses of the eight Sea-viewing Wide Field-of-view Sensor (SeaWiFS) bands were analyzed and a calibration equation was developed that allows conversion of the counts from the radiometer into Earth-exiting radiances.
Abstract: Based on the operating characteristics of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), calibration equations have been developed that allow conversion of the counts from the radiometer into Earth-exiting radiances. These radiances are the geophysical properties the instrument has been designed to measure. SeaWiFS uses bilinear gains to allow high sensitivity measurements of ocean-leaving radiances and low sensitivity measurements of radiances from clouds, which are much brighter than the ocean. The calculation of these bilinear gains is central to the calibration equations. Several other factors within these equations are also included. Among these are the spectral responses of the eight SeaWiFS bands. A band’s spectral response includes the ability of the band to isolate a portion of the electromagnetic spectrum and the amount of light that lies outside of that region. The latter is termed out-of-band response. In the calibration procedure, some of the counts from the instrument are produced by radiance in the out-of-band region. The number of those counts for each band is a function of the spectral shape of the source. For the SeaWiFS calibration equations, the out-of-band responses are converted from those for the laboratory source into those for a source with the spectral shape of solar flux. The solar flux, unlike the laboratory calibration, approximates the spectral shape of the Earth-exiting radiance from the oceans. This conversion modifies the results from the laboratory radiometric calibration by 1–4%, depending on the band. These and other factors in the SeaWiFS calibration equations are presented here, both for users of the SeaWiFS data set and for researchers making ground-based radiance measurements in support of SeaWiFS.

Journal Article
TL;DR: Divergent foraging strategies for terrapins of different head widths may result in habitat partitioning, and food accessibility rather than food abundance may be a limiting factor for Terrapins in areas of high tidal variability.
Abstract: We investigated the foraging ecology of the diamondback terrapin (Malaclemys terrapin) in South Carolina by examining fecal samples for evidence of resource partitioning. From 76-79% of the dietary volume was the salt marsh periwinkle (Littorina irrorata); crabs (Uca pugnax, Sesarma reticulatum, and Callinectes sapidus), barnacles (Balanus), and clams (Polynesoda car- oliniana) constituted the remainder. Dietary partitioning is related to the ontogenetic niche of terrapins. Sexual dimorphism occurs in terrapins with females having larger heads and bodies than males. Terrapins with large head widths ingest significantly larger periwinkles and a wider diversity of prey than terrapins with small head widths. Dietary overlap between males and females is greatest when females are small and decreases as females develop larger enlarged heads. Sexual dimorphism in terrapin trophic structures appears to be partially driven by ecological divergence through resource partitioning. High tides permit terrapins to forage aquatically in upper reaches of the salt marsh. Prey size and distribution are variable and changing tidal heights affect the spatiotemporal availability of prey to foraging terrapins. Divergent foraging strategies for terrapins of different head widths may result in habitat partitioning. Food accessibility rather than food abundance may be a limiting factor for terrapins in areas of high tidal variability. Terrapins are clearly prominent but unrec- ognized macroconsumers in salt marsh ecosystems.

Journal Article
TL;DR: In this article, the authors propose a solution to solve the problem of concurrence of the 2.7.7 dB.0 dB.1 dB.2 dB.5 dB.
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Journal Article
TL;DR: The hypothesis that macroalgal structure may better predict recruitment strength for algal-associated reef fishes that are capable of only limited dispersal than for those that are first subjected to a planktonic dispersive phase was not supported here.

Journal Article
TL;DR: The postglacial succession in the Salmon River incised valley contains two sequences, the upper one incomplete and the lower one accumulated in a wave-dominated estuarine environment under micro-mesotidal conditions.
Abstract: The post-glacial succession in the Cobequid Bay — Salmon River incised valley contains two sequences, the upper one incomplete. The lower sequence contains only highstand system tracts (HST) deposits which accumulated under microtidal, glacio-marine deltaic conditions. The upper sequence contains two, retrogradationally stacked parasequences. The lower one accumulated in a wave-dominated estuarine environment under micro-mesotidal conditions. It belongs to the lowstand system tract (LST) or early transgressive system tract (TST) depending on the timing and location of the lowstand shoreline, and contains a gravel barrier that has been overstepped and preserved with little modification. The upper parasequence accumulated in the modern, macrotidal estuary, and is assignable to the late TST. Recent, net progradation of the fringing marshes indicates that a new HST has begun. The sequence boundary separating the two sequences was formed by fluvial incision, and perhaps also by subtidal erosion during the relative sea level fall. Additional local erosion by waves and tidal currents occurred during the transgression. The base of the macrotidal sands is a prominent tidal ravinement surface which forms the flooding surface between the backstepping estuarine parasequences. Because fluvial deposition continued throughout the transgression, the fluvial-estuarine contact is diachronous and cannot be used as the transgressive surface. The maximum flooding surface will be difficult to locate in the macrotidal sands, but is more easily identified in the fringing muddy sediments. These observations indicate that: (1) large incised valleys may contain a compound fill that consists of more than one sequence; (2) relative sea level changes determine the stratal stacking patterns, but local environmental factors control the nature of the facies and surfaces; (3) these surfaces may have complex origins, and commonly become amalgamated; (4) designation of the transgressive surface (and thus the LST) is particularly difficult as many of the prominent surfaces in the valley fill are diachronous facies boundaries; and (5) the transgression of complex topography may cause geologically instantaneous changes in tidal range, due to resonance under particular geographical configurations.

Journal Article
TL;DR: In this article, the authors present a survey of advances in remote sensing technology and their applications in agriculture, including the development of remote sensing of forest canopy structure and the information extraction problem.
Abstract: Partial table of contents: Advances in Remote Sensing Technology (S. Plummer, et al.). Advances in Field Spectroscopy (E. Milton, et al.). Developments in the Remote Sensing of Forest Canopy Structure (F. Danson). Imaging Spectrometry: A New Tool for Ecology (P. Curran & J. Kupiec). Recent Advances in Understanding SAR Imagery (S. Quegan). Remote Sensing of Geomorphological Processes and Surficial Material Geochemistry in Drylands (A. Millington, et al.). The Remote Sensing of Inland Water Quality (A. Dekker, et al.). Advances in Crop Monitoring by Remote Sensing (M. Steven & K. Jaggard). Remote Sensing and the Information Extraction Problem (F. Danson, et al.). Index.

Journal Article
TL;DR: In this article, the protein, lipid, carbohydrate and chitin composition of 18 species of Antarctic micronektonic crustacea were determined for both fall and winter.
Abstract: Proximate (protein, lipid, carbohydrate and chitin) and elemental (carbon and nitrogen) composition were determined for 18 species of Antarctic micronektonic Crustacea, representing the majority of species found in the Antarctic water column. Individuals used in the analyses were captured during fall and winter; for 8 species data were collected in both seasons. Seven of the 8 species showed some evidence that combustion of body stores were an aid to surviving the winter months; comparison with data from other investigators suggests that most of the species inhabiting shallow and mid-depths exhibit some degree of combustion of body stores during winter. Three types of overwintering stratey e s are proposed for Antarctic zooplankton and micronekton. Type 1, exhibited by some calanoid copepods, is characterized by accumulation of large lipid deposits and a true dormancy, or diapause, during winter. Type 2, exhibited by euphausiids and hyperiid amphipods, is characterized by a marked reduction in metabolic rate, combustion of body substance, opportunistic feeding, but no true dormancy. Type 3, 'business as usual' is exhibited by decapods and gammarid amphipods; it is characterized by an absence of a winter reduction in metabolic rate, combustion of body stores in some species but a lack of combustion or accumulation of energy in others, and opportunistic feeding. Overwintering scenarios computed for Euphausia superba suggest that the impact of the winter season is most severe in the smaller size classes.