Download or read book Estimating Gulf of Maine Zooplankton Distributions Using Multiple Frequency Acoustic Video and Environmental Data written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2001.
Download or read book Estimating Gulf of Maine Zooplankton Distributions Using Multiple Frequency Acoustic Video and Environmental Data written by Joseph David Warren and published by . This book was released on 2001 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis develops methods useful for estimating zooplankton distributions in the field by combining acoustic scattering models and an integrated set of field data. The accuracy of existing scattering models for fluid-like and elastic-shelled animals is determined by analysis of scattering data from individual animals in a laboratory tank. Results indicate that simple two-ray scattering models are accurate and allow predictions of size or orientation of an animal to be made for certain animal orientations. A scattering model for gas-bearing zooplankton is compared with in situ multiple frequency acoustic measurements from siphonophores. Estimates of the numerical density of these animals are made using echo integration data from a scientific echo-sounder. Multiple frequency acoustic scattering data from a survey of an internal wave are analyzed to determine the contributions from biological and physical sources. Net tow data provide information about biological scatterers while temperature and salinity profiles are used with a theoretical scattering model to predict contributions from physical sources. Results indicate that scattering from physical sources is comparable to that from biological sources in certain regions and that scattering spectra may be used to distinguish these sources. Improved estimates of biomass from acoustic scattering data were made by accounting for the scattering contributions from physical sources. This is the first work to quantify the scattering contributions from biological and physical sources of scattering in a field study.
Download or read book Estimating Gulf of Marine Zooplankton Distributions Using Multiple Frequency Acoustic Video and Environmental Data written by and published by . This book was released on 2001 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis develops methods useful for estimating zooplankto distributions in the field by combining acoustic scattering models and an integrated set of field data. The accuracy of existing scattering models for fluid-like and elastic-shelled animals is determined by analysis of scattering data from individual animals in a laboratory tank, Results indicate that simple two-ray scattering models are accurate and allow predictions of size or orientation of an animal to be made for certain animal orientations. A scattering model for gas-bearing zooplankton is compared with in situ multiple frequency acoustic measurements from siphonophores. Estimates of the numerical density of these animals are made using echo integration data from a scientific echo-sounder. Multiple frequency acoustic scattering data from a survey of an internal wave are analyzed to determine the contributions from biological and physical sources. Net tow data provide information about biological scatterers while temperature and salinity profiles are used with a theoretical scattering model to predict contributions from physical sources. Results indicate that scattering from physical sources is comparable to that from biological sources in certain regions and that scattering spectra may be used to distinguish these sources. Improved estimates of biomass from acoustic scattering data were made by accounting for the scattering contributions from physical sources. This is the first work to quantify the scattering contributions from biological and physical sources of scattering in a field study.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2002 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impact of Littoral Environmental Variability on Acoustic Predictions and Sonar Performance written by Nicholas G. Pace and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: The limiting influence of the environment on sonar has long been recognised as a major challenge to science and technology. As the area of interest shifts towards the lit toral, environmental influences become dominant both in time and space. The manyfold challenges encompass prediction, measurement, assessment and adaptive responses to maximize the effectiveness of systems. Although MCM and ASW activities are dom inated in different ways and scales by the environment, both warfare areas have had to consider the significantly changing requirements posed by operations in the littoraL The fundamental scientific issues involved in developing models relating acoustics to the environment are matched in difficulty by the need for data for their validation and eventual practical use for prediction. In many instances the need is for on-line adaptation of systems to changing circumstances whilst other needs are for the Ionger term planning activities. This book and the attached full-color CD are the proceedings of a conference organ ised by the SACLANT Undersea Research Centre, held at Villa Marigola, Lerici, Italy, on 16-20 September 2002. The fundamental problems associated with environmental 1 variability and sonar were explored at a previous SACLANTCEN conference in 1990. These problems have not gone away but, on the one hand are exaggerated by the move to the littoral and on the other hand, are open to treatrnent in new ways that advances in technology and computer power allow.
Download or read book 2000 Ocean Sciences Meeting written by and published by . This book was released on 2000 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Canadian Journal of Fisheries and Aquatic Sciences written by and published by . This book was released on 2003 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S GLOBEC Biological and Physical Studies of Plankton Fish and Higher Trophic Level Production Distribution and Variability in the Northeast Pacific written by Harold P. Batchelder and published by . This book was released on 2005 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Small and Mesoscale Processes and Their Impact on the Large Scale written by Hans van Haren and published by . This book was released on 2004 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Distribution Patchiness and Behavior of Antarctic Zooplankton Assessed Using Multi frequency Acoustic Techniques written by Gareth L. Lawson and published by . This book was released on 2006 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: The physical and biological forces that drive zooplankton distribution and patchiness in an antarctic continental shelf region were examined, with particular emphasis on the Antarctic krill, Euphausia superba. This was accomplished by the application of acoustic, video, and environmental sensors during surveys of the region in and around Marguerite Bay, west of the Antarctic Peninsula, in the falls and winters of 2001 and 2002. An important component of the research involved the development and verification of methods for extracting estimates of ecologically-meaningful quantities from measurements of scattered sound. The distribution of acoustic volume backscattering at the single frequency of 120 kHz was first examined as an index of the overall biomass of zooplankton. Distinct spatial and seasonal patterns were observed that coincided with advective features. Improved parameterization was then achieved for a theoretical model of Antarctic krill target strength, the quantity necessary in scaling measurements of scattered sound to estimates of abundance, through direct measurement of all necessary model parameters for krill sampled in the study region and survey period.
Download or read book Proceedings of the International Conference on Remote Sensing for Marine and Coastal Environments written by and published by . This book was released on 2000 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spring Meeting written by American Geophysical Union. Meeting and published by . This book was released on 1998 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book World Atlas of Seagrasses written by Frederick T. Short and published by Univ of California Press. This book was released on 2003 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seagrasses are a vital and widespread but often overlooked coastal marine habitat. This volume provides a global survey of their distribution and conservation status.
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 710 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 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 Life in the World s Oceans written by Alasdair McIntyre and published by John Wiley & Sons. This book was released on 2010-11-18 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Life in the World's Oceans: Diversity, Abundance and Distribution is a true landmark publication. Comprising the synthesis and analysis of the results of the Census of Marine Life this most important book brings together the work of around 2000 scientists from 80 nations around the globe. The book is broadly divided into four sections, covering oceans past, oceans present, oceans future and a final section covering the utilisation of the data which has been gathered, and the coordination and communication of the results. Edited by Professor Alasdair Mcintyre, Marine Life is a book which should find a place on the shelves of all marine scientists, ecologists, conservation biologists, oceanographers, fisheries scientists and environmental biologists. All universities and research establishments where biological, earth and fisheries science are studied and taught should have copies of this essential book on their shelves. A true landmark publication One of the most important marine science books ever published Contributions from many world leading researchers Synthesis of a huge amount of important data Represents the culmination of 10 years' research by 2000 scientists from 80 countries
