Hypoxia occurs when dissolved oxygen falls below the level necessary to sustain most animal life, often due to fertilizer run-off. This volume reviews how the expanding hypoxic zone in the northern Gulf of Mexico has affected living resources in the Louisiana/Texas shelf. Topics of the 23 chapters include impacts of changing Si/N ratios and phytoplankton species composition, the effect of hypoxia and anoxia on the supply and settlement of benthic invertebrate larvae, and ecological effects of hypoxia in fish, sea turtles, and marine mammals. c. Book News Inc.
Coastal eutrophication has been and still remains an important issue for the scientific community. Despite many efforts to mitigate coastal eutrophication, the problems associated with eutrophication are still far from being solved. This book focusses on the most recent scientific results in relation to specific eutrophication issues, e.g. definition(s) and causes; nutrient loads, cycling and limitation; reference conditions, primary effects and secondary effects; trend reversal (oligotrophication), as well as links to other pressures (climate change and top/down control). It also focusses on monitoring and modelling of coastal eutrophication, and adaptive and science-based nutrient management strategies. The book is based on selected papers from the Second International Symposium on Research and Management of Eutrophication in Coastal Ecosystems, held 20-23 June 2006 in Nyborg, Denmark.
This book provides a snapshot of representative modeling analyses of coastal hypoxia and its effects. Hypoxia refers to conditions in the water column where dissolved oxygen falls below levels that can support most metazoan marine life (i.e., 2 mg O2 l-1). The number of hypoxic zones has been increasing at an exponential rate since the 1960s; there are currently more than 600 documented hypoxic zones in the estuarine and coastal waters worldwide. Hypoxia develops as a synergistic product of many physical and biological factors that affect the balance of dissolved oxygen in seawater, including temperature, solar radiation, wind, freshwater discharge, nutrient supply, and the production and decay of organic matter. A number of modeling approaches have been increasingly used in hypoxia research, along with the more traditional observational and experimental studies. Modeling is necessary because of rapidly changing coastal circulation and stratification patterns that affect hypoxia, the large spatial extent over which hypoxia develops, and limitations on our capabilities to directly measure hypoxia over large spatial and temporal scales. This book consists of 15 chapters that are broadly organized around three main topics: (1) Modeling of the physical controls on hypoxia, (2) Modeling of biogeochemical controls and feedbacks, and, (3) Modeling of the ecological effects of hypoxia. The final chapter is a synthesis chapter that draws generalities from the earlier chapters, highlights strengths and weaknesses of the current state-of-the-art modeling, and offers recommendations on future directions.
A comprehensive volume providing broad and detailed coverage of marine mussels Marine Mussels: Ecology, Physiology, Genetics and Culture provides readers with in-depth, fully up-to-date information on all major aspects of marine mussels. Written by an internationally renowned expert in the field, this authoritative volume addresses morphology, ecology, feeding, phylogeny and evolution, reproduction and larval development, settlement and recruitment, genetics, disease, management of culture systems and more. The book encompasses many different species of marine mussels: genus Mytilus, other important commercial marine genera such as Perna, Aulacomya and Choromytilus, and non-commercial genera including Modiolus, Geukensia, Brachidontes and hydrothermal vent Bathymodiolus. Comprising twelve extensively cross-referenced chapters, the book discusses a diversity of integrated topics that range from fundamental physiology of marine mussels to new techniques being applied in their biology and ecology. Author Elizabeth Gosling reviews contemporary developments and issues in the field such as the use of DNA genetic markers in detecting and diagnosing different strains of pathogenic bacteria, the use of mussels as monitors of marine contaminants, sophisticated modelling techniques that simulate disease and forecast outbreaks, and the impacts of global warming, ocean acidification and hypoxia on marine mussels. Presenting an inclusive, highly detailed treatment of mussel biology, physiology, genetics, and culture, this invaluable resource: Contains thorough descriptions of external and internal anatomy, global and local distribution patterns, the impacts of mussels on marine ecosystems, and the processes of circulation, respiration, excretion and osmoregulation Reflects significant advances in mussel science and new areas of research in marine mussels Describes the fundamentals of mussel aquaculture, the types and levels of contaminants in the marine environment and new approaches for sustainable aquaculture development Discusses the application of genetic methods, population genetics, global breeding programmes and the emerging area of bivalve genomics Addresses the role of mussels in disease transmission to humans, including production and processing controls, regulation of monitoring and quality control Marine Mussels: Ecology, Physiology, Genetics and Culture is essential reading for biological scientists, researchers, instructors and advanced students in the fields of biology, ecology, aquaculture, environmental science, toxicology, genetics, pathology, taxonomy and public health.
During the recent decades, social, political and academic endeavours have been made to improve environmental quality and reduce pollution. In particular, the ocean, sea and coastal areas show varying degrees of impact from the multiple human activities carried out in the terrestrial as well as in the aquatic environment. Ecology is a science which studies the relationship between organisms and the surrounding environment and in the modern era, the marine world is getting increasing attention. For centuries it has been the final reservoir of human garbage; later it became an oil farm with a concomitant increase of coastal population growth and unplanned growth of the fishing industry and the increasing use of sea routes for cargo transport and recreational uses (cruises). All this led to rising contamination with negative effects on biota and even human health. It is then imperative to know the current situation of the world's oceans: that is the main purpose of this book, to document at a glance the latest research in the field of ocean pollution.
Environmental problems in coastal ecosystems can sometimes be attributed to excess nutrients flowing from upstream watersheds into estuarine settings. This nutrient over-enrichment can result in toxic algal blooms, shellfish poisoning, coral reef destruction, and other harmful outcomes. All U.S. coasts show signs of nutrient over-enrichment, and scientists predict worsening problems in the years ahead. Clean Coastal Waters explains technical aspects of nutrient over-enrichment and proposes both immediate local action by coastal managers and a longer-term national strategy incorporating policy design, classification of affected sites, law and regulation, coordination, and communication. Highlighting the Gulf of Mexico's "Dead Zone," the Pfiesteria outbreak in a tributary of Chesapeake Bay, and other cases, the book explains how nutrients work in the environment, why nitrogen is important, how enrichment turns into over-enrichment, and why some environments are especially susceptible. Economic as well as ecological impacts are examined. In addressing abatement strategies, the committee discusses the importance of monitoring sites, developing useful models of over-enrichment, and setting water quality goals. The book also reviews voluntary programs, mandatory controls, tax incentives, and other policy options for reducing the flow of nutrients from agricultural operations and other sources.
In the marine environment, single-celled, microscopic, plant-like organisms naturally occur in the well-lit surface layer of any body of water. These organisms, referred to as phytoplankton or microalgae, form the base of the food web upon which nearly all other marine organisms depend. Algal bloom is a rapid increase in or accumulation of the population of about 300 species of algae due to excess nutrients (eutrophication), and is of major global interest as it causes reduction in species diversity, abrupt changes in water quality, and discoloration of the water (green, yellow, brown or red) depending on the species of algae and the type of pigments they contain. Dying blooms can also be an environmental concern as when the cells sink and decay, bacteria break down the organic material, which in turn strips oxygen from the water. This microbial oxygen demand at times leads to very low oxygen levels in the bottom waters, harming aquatic life. Documentation of this sporadic high abundance of algae, together with the significant species richness of the diatoms, requires comprehensive studies in the Sundarban coastal environment, which is facing severe degradation due to natural & anthropogenic stressors. In addition, a better understanding of the effects of algal blooms on seafood quality, the complex biological, chemical and physical interactions and subsequent effects on trophodynamics is needed to develop strategies for effective coastal zone management. The book discusses the occurrence of harmful algal blooms (HABs) caused by the dinoflagellates of the genus Alexandrium and Karenia, or diatoms of the genus Pseudo-nitzschia, which have large and varied impacts on marine ecosystems (such as large-scale marine mortality events that have been associated with various types of shellfish poisonings) depending on the species involved, the environment where they are found, and the mechanism by which they exert negative effects. HABs represent a major environmental problem in all regions of the U.S., and their occurrence is on the rise due to increased nutrient pollution. HABs have severe impacts on human health, aquatic ecosystems, and the economy. Such blooms, known colloquially as red tides due to their red or brown hues, are increasing in frequency and magnitude worldwide as a result of changes in oceanic climate, increased coastal eutrophication and enhanced long-distance dispersal in ballast water. As such, the book offers an in-depth account of the complex biological, chemical and physical interactions of the algal blooms (both innocuous and harmful ones). It also discusses the highly topical issue of the impact of global climate change on the frequency and severity of HABs in the context of alterations in temperature, stratification, light and ocean acidification. Focusing on both basic and applied limnology, this book is a reliable and up-to-date reference resource for students, teachers and researchers engaged in the field of coastal research/management at regional and global scales.
This book is a product of the joint JGOFS (Joint Global Ocean Flux Study)/LOICZ (Land–Ocean Interactions in the Coastal Zone) Continental Margins Task Team which was established to facilitate continental margins research in the two projects. It contains signi cant information on the physical, biogeochemical, and ecosystems of continental margins nationally and regionally and provides a very valuable synthesis of this information and the physical, biogeochemical and ecosystem processes which occur on continental margins. The publication of this book is timely as it provides a very strong foundation for the development of the joint IMBER (Integrated Marine Biogeochemistry and Ecosystems Research)/LOICZ Science Plan and Implemen- tion Strategy for biogeochemical and ecosystems research in the continental margins and the impacts of global change on these systems. This initiative will move forward integrated biogeochemical and ecosystems research in the continental margins. We thank all the contributors to this volume and especially Kon-Kee Liu who has dedicated a great deal of time to ensuring a high-quality book is published. IMBER Scienti c Steering Committee Julie Hall LOICZ Scienti c Steering Committee Jozef Pacyna v 1 Preface In general, interfaces between the Earth’s larger material reservoirs (i. e. , the land, atmosphere, ocean, and sediments) are important in the control of the biogeoche- cal dynamics and cycling of the major bio-essential elements, including carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and silicon (Si), found in organic matter and the inorganic skeletons, shells, and tests of benthic and marine organisms.
