AlSammaliah IsJand is one of more than 200 islands belonging to United Arab Emirates in the Arabian Gulf. This inshore shallow island has a surface area of about 32 km2; lies at the north east coast of Abu Dhabi and is connected to the Arabian Gulf through Khor Laffan. The abundance of ciliates at Al-Sammaliah Island water showed an annual cycle with highest ciliate numbers (23 ml-1) in the spring, and lowest values (0.5 ml-1) in summer. The ciliate community was generally dominated by non-loricate oligotrichs, tintinnids, and other planktonic forms but by lower abundance, as well as a seasonally varying numbers of benthic forms. Nanoflagellates that could provide a food supply for the filter -
feeding ciliates were especially numerous in the spring, but this was not the case for bacteria. The high populations of ciliates and flagellates reflect the productivity while the production of bacteria is presumably a more important component at the base of the food chain at the island water. Total nanoflagellates, heterotrophic nanoflagellates and bacteria
were enumerated to gain some indication of the food resources for ciliates. In this connection, the filtration activities of the heterotrophic flagellates and ciliates are compared with the population densities of bacteria, flagellates and filterfeeding ciliates. Moreover, the time required for the whole water body to be filtered by flagellates and ciliates was calculated.