Sediment Organism Interactions

IN 1998, SCIENTISTS representing more than fifty international research organizations met to seek answers to environmental questions regarding pollution, ocean cleansing, and the impact that changes in sediment layers have on benthic organisms and the ecosystems that depend on them. Their findings consider these topics, identify opportunities for future investigations, and promote active partnerships between federal regulatory agencies and the academic community in order to preserve and enhance natural aquatic resources.

The International Association for Sediment Water Science sponsors a symposium triennially, during which the latest developments in the study of interactions between sediments and their overlying waters are presented. These proceedings are a collection of papers submitted following the 7th Symposium held in Baveno, Italy, during 22nd - 25th September, 1996. The study of sediment/water interactions crosses disciplinary and ecosystem boundaries. The work presented in this volume demonstrates the importance of multidisciplinarity to the field with papers included in the general subject areas of sediment/water dynamics, sediment/contaminant interactions, the role of sediments in element cycles, the use of sediments as historical indicators, sediment/organism interactions, and studies of sedimentary environments in remote areas.

Marine sediments support complex interactions between macro-and microorganisms that have global implications for carbon and nutrient cycles. What is the state of the science on such interactions from coastal and estuarine environments to the deep sea? How does such knowledge effect environmental management? And what does future research hold in store for scientists, engineers, resource managers, and educators?Interactions between Macro- and Microorganisms in Marine Sediments responds to these questions, and more, by focusing on:? Interactions between plants, microorganisms, and marine sediment? Interactions between animals, microorganisms, and marine sediment? Interactions between macro- and microorganisms and the structuring of benthic communities? Impact of macrobenthic activity on microbially-mediated geochemical cycles in sediments? Conceptual and numeric models of diagenesis that incorporate interactions between macro- and microorganismsHere is an authoritative overview of the research, experimentation and modeling approaches now in use in our rapidly evolving understanding of life in marine sediments.

Introduction The Fourth Symposium on Sediment/Water Interactions was held in Melbourne, Australia, February 16-20th, 1987. The previous three symposia were held in Amsterdam, Kingston (Ontario), and Geneva, In keeping with the approach established in Geneva, contributions addressed sediment/water interactions related to both fresh and salt water conditions. More than 160 papers were given in Melbourne, including more than 20 poster presentations, and collected Abstracts are available from Dr. B. T. Hart. A total of 51 papers, subsequently, have been published as proceedings of the Melbourne Symposium; 45 of these appear in this issue of Hydrobiologia. A further six appeared earlier as a selection of papers in J. Environ. Geol. and Water Science (1988, issue # 1); these six papers appear in abstract form, only, in the present pUblication. Although concerned with the global environment, the International Association for Sediment Water Science attempts to ensure that there is a genuine opportunity for participants to focus on regional issues throughout the world and, in particular, to provide a local forum for their presentation. The Melbourne meeting was particularly successful in achieving this objective, and Australasia was well represented by about 36 percent of the contributors. About 27 percent were from Europe, 17 percent from North America, 7 percent from China and Japan, 7 percent from Southeast Asia and India, and about 6 percent came from other areas. In all, 25 countries were represented.

The tidal coastline presents a fascinating ecological world. Rocky shores with their recurrent zonation of algae and sessile invertebrates demonstrate the orderliness of nature, apparently obeying general explan atory principles. The niche theory could just as well have hatched out of the tight species-packing on the coral reef flats. Fluxes of carbon and nitrogen are best studied in mangroves and salt marshes with their outstanding primary productivity; the bare mud and sands of the tidal flats are different. Their ecological treasures are well concealed, and perhaps not to everybody's taste. Pick up a piece of tidal sediment and see how it resembles a large, rotten cheese! It smells, is slimy and sticky, is punched with holes and crowded with various worms. Tidal flats receive detritus from both the land and the sea. They sup port a rich benthic community which attracts birds from far distant breeding grounds, and serves as a nursery for crabs, shrimp and fish. Tidal flats are a busy ecological turntable. They import low valued organic matter, and they export well-fed birds to the land and grown-up fish to the sea. They offer ideal opportunities for aquaculture but are also used as dumping grounds for industrial wastes. All this may call for a marine ecologist to investigate the basic processes involved. Yet there is still another reason.

The papers appearing in this volume reflect the current attention in sediment/water science to five main topics of investigation: Sediment dynamics in estuaries, coastal waters, lakes, reservoirs and rivers; Sediment-associated biological processes; Contaminant accumulation, distribution and geochemistry; Fluxes from sediments; and Element cycling. Contributors address sediment/water interactions related to both fresh and salt water conditions.