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.
Since 1985, scientists have been documenting a hypoxic zone in the Gulf of Mexico each year. The hypoxic zone, an area of low dissolved oxygen that cannot s- port marine life, generally manifests itself in the spring. Since marine species either die or ee the hypoxic zone, the spread of hypoxia reduces the available habitat for marine species, which are important for the ecosystem as well as commercial and recreational shing in the Gulf. Since 2001, the hypoxic zone has averaged 2 1 16,500 km during its peak summer months , an area slightly larger than the state 2 2 of Connecticut, and ranged from a low of 8,500 km to a high of 22,000 km . To address the hypoxia problem, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force (or Task Force) was formed to bring together represen- tives from federal agencies, states, and tribes to consider options for responding to hypoxia. The Task Force asked the White House Of ce of Science and Technology Policy to conduct a scienti c assessment of the causes and consequences of Gulf hypoxia through its Committee on Environment and Natural Resources (CENR).
Most water resources managers, scientists, and other experts would agree that nonpoint source pollution is a more pressing and challenging national water quality problem today than point source pollution. Nonpoint sources of pollutants include parking lots, farm fields, forests, or any source not from a discrete conveyance such as a pipe or canal. Of particular concern across the Mississippi River basin (MRB) are high levels of nutrient loadings--nitrogen and phosphorus--from both nonpoint and point sources that ultimately are discharged into the northern Gulf of Mexico (NGOM). Nutrients emanate from both point and nonpoint sources across the river basin, but the large majority of nutrient yields across the MRB are nonpoint in nature and are associated with agricultural activities, especially applications of nitrogen-based fertilizers and runoff from concentrated animal feeding operations. Improving Water Quality in the Mississippi River Basin and Northern Gulf of Mexico offers strategic advice and priorities for addressing MRB and NGOM water quality management and improvements. Although there is considerable uncertainty as to whether national water quality goals can be fully realized without some fundamental changes to the CWA, there is general agreement that significant progress can be made under existing statutory authority and budgetary processes. This book includes four sections identifying priority areas and offering recommendations to EPA and others regarding priority actions for Clean Water Act implementation across the Mississippi River basin. These sections are: USDA's Mississippi River Basin Healthy Watersheds Initiative; Numeric Water Quality Criteria for the northern Gulf of Mexico; A Basinwide Strategy for Nutrient Management and Water Quality; and, Stronger Leadership and Collaboration.
Since 1985, scientists have been documenting a hypoxic zone, an area of low dissolved oxygen that cannot support marine life, in the Gulf of Mexico each year. Since marine species either die or flee the hypoxic zone, the spread of hypoxia reduces the available habitat for marine species, which are important for the ecosystem as well as commercial and recreational fishing in the Gulf. To address the hypoxia problem, the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force was formed to bring together representatives from federal agencies, states and tribes to consider options for responding to hypoxia. This book summarises major findings and recommendations with regard to hypoxia in the Northern Gulf of Mexico.
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 classroom resource provides clear, concise scientific information in an understandable and enjoyable way about water and aquatic life. Spanning the hydrologic cycle from rain to watersheds, aquifers to springs, rivers to estuaries, ample illustrations promote understanding of important concepts and clarify major ideas. Aquatic science is covered comprehensively, with relevant principles of chemistry, physics, geology, geography, ecology, and biology included throughout the text. Emphasizing water sustainability and conservation, the book tells us what we can do personally to conserve for the future and presents job and volunteer opportunities in the hope that some students will pursue careers in aquatic science. Texas Aquatic Science, originally developed as part of a multi-faceted education project for middle and high school students, can also be used at the college level for non-science majors, in the home-school environment, and by anyone who educates kids about nature and water. To learn more about The Meadows Center for Water and the Environment, sponsors of this book's series, please click here.
A comprehensive, state-of-the-art synthesis of biogeochemical dynamics and the impact of human alterations at major river-coastal interfaces for advanced students and researchers.
Dead zones are on the rise... Human activity has caused an increase in uninhabitable, oxygen-poor zones--also known as "dead zones"--in our waters. Oxygen is the third most abundant element in the universe, and it is a necessity for nearly all life on Earth. Yet many rivers, estuaries, coastal waters, and parts of the open ocean lack enough of it. In this book, David L. Kirchman explains the impacts of dead zones and provides an in-depth history of oxygen loss in water. He details the role the agricultural industry plays in water pollution, showcasing how fertilizers contaminate water supplies and kickstart harmful algal blooms in local lakes, reservoirs, and coastal oceans. Algae decomposition requires so much oxygen that levels drop low enough to kill fish, destroy bottom-dwelling biota, reduce biological diversity, and rearrange food webs. We can't undo the damage completely, but we can work together to reduce the size and intensity of dead zones in places like the Gulf of Mexico, Chesapeake Bay, and the Baltic Sea. Not only does Kirchman clearly outline what dead zones mean for humanity, he also supplies ways we can reduce their deadly impact on human and aquatic life. Nutrient pollution in some regions has already begun to decline because of wastewater treatment, buffer zones, cover crops, and precision agriculture. More needs to be done, though, to reduce the harmful impact of existing dead zones and to stop the thousands of new ones from cropping up in our waters. Kirchman provides insight into the ways changing our diet can reduce nutrient pollution while also lowering greenhouse gasses emitted by the agricultural industry. Individuals can do something positive for their health and the world around them. The resulting book allows readers interested in the environment--whether students, policymakers, ecosystem managers, or science buffs--to dive into these deadly zones and discover how they can help mitigate the harmful effects of oxygen-poor waters today.
