Download or read book Physical Processes and Zooplankton Distribution in the Great South Channel written by Ari Wenkart Epstein and published by . This book was released on 1995 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses the question, "How do small-scale physics and biology combine to produce dense aggregations of certain species of zooplankton in the Great South Channel (GSC) of the Gulf of Maine?" The thesis consists of three relatively independent parts: an observational study made while following two right whales as they fed on dense patches of the copepod Galanus finmarchicus in the northern GSC; a detailed description of a tightly integrated set of biological and physical observations made in the GSC by means of a new instrument, the Video Plankton Recorder (VPR); and a two-dimensional Eulerian numerical model that simulates one way in which a physical flow field, combined with a biological behavior pattern, may produce dense plankton patches at a convergent front. Part I: Data from a wide variety of instruments was combined to produce a coherent picture of the physical and biological environment near two feeding right whales observed in June, 1989. Instruments included a CTD (with transmissometer), a MOCNESS net system, a 150-kHz ADCP, and a towed acoustic plankton profiler operating at 120 and 200 kHz. Acoustic data were intercalibrated with net-tow data and with "noise" in the transmissometer signal in order to estimate copepod abundance in the plankton patches on which the whales were feeding. One of the whales was observed to reverse course when copepod abundance dropped below about 1.5- 4.5 x 103 copepods/m3, which is consistent with independent estimates of the density of copepods necessary for a right whale to gain more energy from the prey it ingests than it loses to the extra hydrodynamic drag it experiences while feeding. Part II: The VPR is a towed underwater microscope designed to image plankton non-invasively with sufficient resolution to obtain information on the spatial distribut ion of organisms on scales ranging from millimeters to hundreds of kilometers. CTD instrumentation mounted on the VPR makes it possible to correlate biological and hydrographic data with great precision. This study reports data from one transect made across the GSC in May, 1992. The data show close correlations between hydrographic features (such as fronts, plumes and water masses) and broad-scale plankton distribution. In addition, it was possible to correlate the fine-scale (order tens of meters) patchiness in plankton distribution with the local stability of the water column (as indicated by gradient Richardson number). In one case, biological data provided an aid in determining the origin of one of the observed water masses. Part III: This chapter presents a two-dimensional Eulerian numerical model that shows how depth-keeping swimming behavior on the part of an organism, combined with a convergent flow field at a surface front, can create dense patches of the organism. In this model a steady-state flow field and vertical diffusivity field are prescribed, along with the initial distribution of the plankton. The plankton swim vertically with speeds that depend only on depth, but the form of that depth-dependence may take into account such factors as the vertical variation in light level or in the concentration of some prey organism. An analysis of various nondimensional parameters associated with the model illustrates the roles played in determining the final structure of the patch by such factors as diffusion, water velocity and details of the animals' swimming behavior. Output from the model is compared with data taken at a dense plankton patch observed near a front in the northern Great South Channel in early June, 1989

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Occurrence Abundance and Seasonal Distribution of the Zooplankton of the Great South Bay Long Island New York written by Philip G. Wendt and published by . This book was released on 1973 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlantic Update written by and published by . This book was released on 1986 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical and Biological Controls of Copepod Aggregation and Baleen Whale Distribution written by and published by . This book was released on 2009 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our long-term goal is to develop a fundamental understanding of the physical and biological mechanisms that aggregate zooplankton on spatial scales of hundreds of meters to hundreds of kilometers. These aggregation processes have a profound effect on the distribution, movements, and behavior of top predators, including those that feed directly on zooplankton (e.g., basking sharks, manta rays, right whales). While all marine mammals rely on prey aggregation processes for their survival, baleen whales are perhaps most dependent upon these processes because of the enormous quantities of food they must consume daily. Therefore, we have chosen to focus our long-term research efforts on the interactions between baleen whales, zooplankton, and ocean physics to better understand the environmental factors that influence marine mammal distribution. The specific objectives of this study are as follows: (1) to elucidate the mechanisms of copepod aggregation in the Great South Channel, a major springtime feeding area for right, sei, humpback, and fin whales in the southwestern Gulf of Maine; and (2) to examine the relationship between these mechanisms and the distribution and abundance of baleen whales.

Download or read book Kinetic Processes of Mantle Minerals written by Kenneth Tadao Koga and published by . This book was released on 2000 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation discusses the experimental results designed to constrain the processes of MORB generation. The main focus of this study is to investigate the location and the related processes of the transformation boundary from spinel to garnet peridotite facies at subsolidus conditions, because the presence of garnet in melting residues has significant influence to the conclusion drawn from geochemical/geophysical observations. Using an approach that monitors the rate of reaction progresses, the experimental results confirmed the presence of a region that garnet and spinel coexist in peridotite compositions. The trace element distribution among the product phases (opx and cpx) subsequent to the garnet breakdown reaction is in disequilibrium, due to the differences of diffusivity between major and trace elements. The presence of disequilibrium distribution in nature may be used to infer time scales of geodynamic processes. Diffusion coefficients of A1 in diopside are experimentally determined, and used for modeling the equilibration of major elements in pyroxene during MORB genesis. In summary, this dissertation contributes two major inferences: the location of the transformation boundaries of the gamet-spinel peridotite; the presence of disequilibrium trace elements distribution with equilibrium major elements distribution in mantle pyroxenes.

Download or read book Biological Chemical Oceanography Program Abstract Book written by and published by . This book was released on 1994 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book American Doctoral Dissertations written by and published by . This book was released on 1994 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Pacific Arctic Region written by Jacqueline M. Grebmeier and published by Springer. This book was released on 2014-06-10 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Pacific Arctic region is experiencing rapid sea ice retreat, seawater warming, ocean acidification and biological response. Physical and biogeochemical modeling indicates the potential for step-function changes to the overall marine ecosystem. This synthesis book was coordinated within the Pacific Arctic Group, a network of international partners working in the Pacific Arctic. Chapter topics range from atmospheric and physical sciences to chemical processing and biological response to changing environmental conditions. Physical and biogeochemical modeling results highlight the need for data collection and interdisciplinary modeling activities to track and forecast the changing ecosystem of the Pacific Arctic with climate change.

Download or read book ICES Zooplankton Methodology Manual written by Roger Harris and published by Elsevier. This book was released on 2000-02-14 with total page 707 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term "zooplankton" describes the community of floating, often microscopic, animals that inhabit aquatic environments. Being near the base of the food chain, they serve as food for larger animals, such as fish. The ICES (International Council for the Exploration of the Sea) Zooplankton Methodology Manual provides comprehensive coverage of modern techniques in zooplankton ecology written by a group of international experts. Chapters include sampling, acoustic and optical methods, estimation of feeding, growth, reproduction and metabolism, and up-to-date treatment of population genetics and modeling. This book will be a key reference work for marine scientists throughout the world. - Sampling and experimental design - Collecting zooplankton - Techniques for assessing biomass and abundance - Protozooplankton enumeration and biomass estimation - New optical and acoustic techniques for estimating zooplankton biomass and abundance - Methods for measuring zooplankton feeding, growth, reproduction and metabolism - Population genetic analysis of zooplankton - Modelling zooplankton dynamics This unique and comprehensive reference work will be essential reading for marine and freshwater research scientists and graduates entering the field.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996-09 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Marine Pollution Program written by and published by . This book was released on 1988 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Influence of the Loop Current on the Diversity Abundance and Distribution of Zooplankton in the Gulf of Mexico written by Katie Rathmell and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Physical processes in the Gulf of Mexico (GOM) and mesoscale (10-300 km) processes associated with the Loop Current are fairly well known. However, little is known about the physical/ biological interactions of the frontal boundary system of the Loop Current. Zooplankton abundance and distribution was determined at 28 stations in the vicinity of the Loop Current. Species richness was high at all stations. Copepods comprised 60% of the total zooplankton collected. Oithona plumifera, Nannocalanus minor and Euchaeta marina were the most abundant copepods. Chaetognaths and ostracods were also very abundant and made up 11 and 5 % respectively of the zooplankton total. Total zooplankton abundance was higher at the boundary of the LC than it was inside the LC but not significantly different from abundances outside of the LC. Stations in the western Gulf of Mexico and on the western boundary had the highest abundances of zooplankton overall. The chlorophyll concentrations at the chlorophyll maximum were higher at the boundary of the LC than inside the LC. Physical-biological processes associated with the frontal boundary of the LC appear to influence the abundance and distribution of zooplankton in the GOM.

Download or read book The Biomass Spectrum written by S. R. Kerr and published by Columbia University Press. This book was released on 2001-08-29 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kerr and Dickie propose the development of a new ecological theory, one that can lead to a more effective remedy for the drastic effects of heavy fishing on natural communities of organisms in both marine and freshwater environments. By plotting the densities of the biomass of all organisms in a given community by body-size classes, the authors provide empirical evidence of what they term "the biomass body-size spectrum" in the world's oceans. After examining this evidence, they propose an underlying theory of predator-prey energy transfer: larger species eat smaller species, providing energy exchange across all species within an ecosystem. Providing the first comprehensive synthesis of the energy flow within the biomass spectrum, this book demonstrates not only a new understanding of the self-organizing properties of ecological production systems but also the potential of the biomass spectrum methodology for offering practical remedies when these natural systems are exploited by humans.

Download or read book The Journal of Cetacean Research and Management written by and published by . This book was released on 2000 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Biology of Calanoid Copepods written by and published by Academic Press. This book was released on 1998-06-02 with total page 721 pages. Available in PDF, EPUB and Kindle. Book excerpt: This special volume of Advances in Marine Biology covers in detail the biology of calanoid copepods. Copepods are probably the most numerous multicellular organisms on earth. They are aquatic animals that live in both marine and fresh water, and are of prime importance in marine ecosystems as they form a direct link between phytoplankton and fish. This volume is essential for all marine biologists.Advances in Marine Biology contains up-to-date reviews of all areas of marine science, including fisheries science and macro/micro fauna. Each volume contains peer-reviewed papers detailing the ecology of marine regions.

Download or read book Marine Research written by and published by . This book was released on 1969 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: