91桃色

Abstract

Salinity changes in Shatt Al-Arab estuary and North-West Arabian Gulf were monitored and reviewed in terms of the shortage of freshwater inflows to the Shatt Al-Arab estuary. Data from previous and current surveys on marine mammals in the area have also been checked and compared for the purpose of studying the biodiversity under the newly-developed circumstances. One third of the world?s 81 species of cetaceans, are thought to occur off the shores in the area. Dolphins or porpoises are more commonly known as they occur in larger numbers. In general, in the deep waters different species were recorded than warm, sandy shallow waters. The new check list is prepared according to recent surveys in the neighboring Arab Gulf countries and the known checklist of mammals in Iraqi waters. Comparison between the North and South areas of the Gulf showed that the ecosystem of the southern parts of the Gulf were more stable than the Northern part in response to the variable ecosystem of the estuary. Spatial variation of the marine mammals of the southern part was governed by the occurrence of feeding habitats rather than direct response to salinity variations. Alteration of seaweed?s habitats in response to water pollution is reported to have a direct effect on the biodiversity of mammals in the Gulf. Threats from other hazardous factors to mammals of the Gulf were reported. Most of them are related to fishing activities and accidentally killing by ships and boats. The results of this review were discussed in terms of salinity tolerance, hazardous ecological factors and spatial variation

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