Following closure of the Aswan High Dam in 1965 and the elimination of annual flooding of the Nile basin, the Mediterranean Sea fishery off the Egyptian Coast collapsed. Beginning in the mid-1980's, landings began a dramatic recovery and have now reached levels well above those of the pre-dam fishery. Three major hypotheses have been advanced to explain the apparent increase in secondary production on the Egyptian Coast: replacement of the Nile flood nutrients by anthropogenic sources of nitrogen and phosphorous from agricultural drainage and sewage; replacement of Nile nutrients by a change in the large scale circulation of the Eastern Mediterranean waters; and that the apparent increase in production is actually an expansion of fishing effort and improved data collection and statistics.
The principal investigator will track stable nitrogen isotopes from alternate nitrogen sources to the formation of particulate organic matter, fish, and prawns in the large Nile delta lagoons and in fisheries landings from the nearshore Egyptian Shelf waters. Sources include nitrogen derived from land drainage, sewage, Nile water, and Mediterranean Shelf water. Historical changes in inorganic nitrogen over the past century will be examined in sediment cores from delta lagoons and from the near shore shelf. Progress reports will be posted regularly in log form on a website created for middle and secondary public school children. Classroom visits to local Rhode Island schools will emphasize comparing human impacts from sewage, fertilizers, and factories in Narragansett Bay to those in Egypt. With the assistance of colleagues in the National Institute of Oceanography and Fisheries, Egypt, information will be translated into Arabic and published in popular Arabic journals such as Environment & Development Monthly and on heavily visited websites such as Islam Online. Funding for this project is provided by the Office of International Science and Engineering and by the Biological Oceanography Program.
