What do we know about Eilat (Red Sea) reef degradation? A critical examination of the published literature

During the last four decades, the coral reef at Eilat, northern Red Sea, has undergone major changes. Increasing impacts from human activities, coupled with those from natural disasters, have set off its current poor state. Here, I critically overview the salient features for Eilat's reef degradation published since the 1960s. Although this reef is one of the most intensively studied small coral reef worldwide, the literature elucidates that the available results are exceedingly fragmented, offering only scanty knowledge for the causes and pathways of the reef deterioration. During the years, 1975-2000, scarcely any reef evaluation had been done and the reef at Eilat was not well characterized to establish baseline data for future evaluations and for analyzing the trends. Even the follow up studies on the extreme low tide episode (occurred during 1970) are limited and localized, and cannot be used as a model case in calibrating Eilat reef status. Natural forces affecting the reef at Eilat are understood only vaguely, and coral assemblages/recruitments, even between neighboring sites, vary markedly in any studied biological-ecological parameter. The importance of the complex networks of interactions between algae, their grazers and corals for structuring coral assemblages, were overlooked, and massive algal growths were mistakenly attributed to anthropogenic impacts alone. Whereas, no long-term study can provide much indication for future prospects, at present, the tourist industry is probably the major cause for reef decline. Surprisingly, the literature further unveils at some sites various ecological properties, such as species diversity and densities of coral species and colonies, similarly to the values recorded decades ago and reveals that the paucity of information has led to conclusions unsubstantiated by robust sets of experiments. At this stage, therefore, decisive conclusions pertaining to the causes and pathways of Eilat reef degradation cannot be reached. Four future prospectuses are outlined, including the need for implementation of active restoration measures.