This book elucidates the vital but often neglected relationship between bottom soil and water quality. An understanding of this important connection is essential for maintaining water quality within optimum ranges for shrimp and fish. It is the first volume to provide information on topics from soil science essential to pond aquaculture. The impact of soil-water interactions on water quality is examined, and the volume provides important methods for enhancing the soil conditions in ponds.

Aquaculture pond managers measure water-quality variables and attempt to maintain them within optimal ranges for shrimp and fish, but surprisingly little attention is paid to pond soil condition. Soil-water interactions can strongly impact water quality, and soil factors should be considered in aquaculture pond management. The importance of soils in pond management will be illustrated with an example from pond fertilization and another from aeration. Pond fertilization may not produce phytoplankton blooms in acidic ponds. Total alkalinity is too low to provide adequate carbon dioxide for photosynthesis, and acidic soils adsorb phosphate added in fertilizer before phytoplankton can use it. Agricultural lime stone application can raise total alkalinity and neutralize soil acidity. The amount of limestone necessary to cause these changes in a pond depends on the base unsaturation and exchange acidity of the bottom soil. Two ponds with the same total alkalinity and soil pH may require vastly different quantities of limestone because they differ in exchange acidity. Aeration enhances dissolved oxygen concentrations in pond water and permits greater feed inputs to enhance fish or shrimp production. As feeding rates are raised, organic matter accumulates in pond soils. In ponds with very high feeding rates, aeration may supply enough dissolved oxygen in the water column for fish or shrimp, but it may be impossible to maintain aerobic conditions in the surface layers of pond soil. Toxic metabolites produced by microorganisms in anaerobic soils may enter the pond water and harm fish or shrimp.

Aquaculture pond managers measure water-quality variables and attempt to maintain them within optimal ranges for shrimp and fish, but surprisingly little attention is paid to pond soil condition. Soil-water interactions can strongly impact water quality, and soil factors should be considered in aquaculture pond management. The importance of soils in pond management will be illustrated with an example from pond fertilization and another from aeration. Pond fertilization may not produce phytoplankton blooms in acidic ponds. Total alkalinity is too low to provide adequate carbon dioxide for photosynthesis, and acidic soils adsorb phosphate added in fertilizer before phytoplankton can use it. Agricultural lime stone application can raise total alkalinity and neutralize soil acidity. The amount of limestone necessary to cause these changes in a pond depends on the base unsaturation and exchange acidity of the bottom soil. Two ponds with the same total alkalinity and soil pH may require vastly different quantities of limestone because they differ in exchange acidity. Aeration enhances dissolved oxygen concentrations in pond water and permits greater feed inputs to enhance fish or shrimp production. As feeding rates are raised, organic matter accumulates in pond soils. In ponds with very high feeding rates, aeration may supply enough dissolved oxygen in the water column for fish or shrimp, but it may be impossible to maintain aerobic conditions in the surface layers of pond soil. Toxic metabolites produced by microorganisms in anaerobic soils may enter the pond water and harm fish or shrimp.

A comprehensive source of information on all aspects of shrimp production, this reference covers not only the global status of shrimp farming, but also examines shrimp anatomy and physiology. From nutrition to health management and harvesting issues to biosecurity, this well-researched volume evaluates existing knowledge, proposes new concepts, and questions common practices. With an extensive review on worldwide production systems, this compilation will be highly relevant to research scientists, students, and shrimp producers.

The idea of convening an international workshop on hypertrophic ecosystems originated during the 20th S.I.L. Congress in Copenhagen. A group of about 30 delegates met there in an informal gathering to discuss the specific problems of lakes which have reached a noxious stage of eutrophication. This ad hoc group realized its own specific identity within the limnological community and suggested the organization of a specialized future meeting on hypertrophic ecosystems. After two years of preparatory work, the workshop was fmally held in Vaxjo, Sweden, between September 10 and 14, 1979, on the premises of the University campus. The Institute of Limnology, University of Lund (Professor Sven Bjork), undertook the task of host and organizer. The City ofVaxjo and the University of Lund co-sponsored the event, which was held under the auspices and patronage of the Societas Internationalis Limnologiae. The objective of the workshop was to seek better understanding of highly-eutrophic, disturbed and unstable aquatic ecosystems (lakes, reservoirs and ponds developing noxious algal and bacterial blooms, fluctuating in their water quality on a daily and seasonal scale, producing gases, off-flavor and toxic substances, experiencing periodic anoxia and massive fish kills, etc.), Le., systems requiring corrective measures and new concepts for their solution beyond those generally accepted for 'normal' eutrophic systems.

Ponds are a primary production system to a wide variety of freshwater fish species. Each species have specific and unique nutrient needs and successful pond fertilization is critical to a successful aquaculture enterprise. Aquaculture Pond Fertilization: Impacts of Nutrient Input on Production provides state-of-the-art information for successful fertilization strategies for a broad range of pond-raised species. Aquaculture Pond Fertilization attempts to rectify the seemingly contradictory nutrient recommendations by clearly defining the goals of specific types of aquaculture. Chapters are divided into three sections: The first reviews basic concepts in fertilization applicable to all pond-based production. The second looks at specific nutrient management approaches. The third and final section of chapters looks specifically at key freshwater pond species ranging from tilapia to perch and discusses specific fertilization needs for the successful rearing of these in-demand fish. Looking across species with chapters contributed by leaders in the field Aquaculture Pond Fertilization provides succinct single-volume coverage of an oft-neglected, but vitally important topic in aquaculture production.

In 2002, sixty international specialists met to discuss problems of high P-unavailability as a soil nutrient for crops, and the hazards of increased phosphate input to aquatic habitats from industrial and mining activities, sewage disposal, detergents, and other sources. Among the presentations were updated solutions to enhance P-uptake by plants, bioremediation potential in the rehabilitation of ecosystems, taxonomic characterization interactions with mycorrizae, the physiological and molecular basis of PSM, and more.