Historically, the Red Sea Coral Reefs have been known for their high level of coral species diversity and high levels of endemism- and Eilat is no exception. There are more than 270 coral species that are home to more that 2,500 species of underwater organisms, many of which are endemic. Over the years, the unpredictable midday low tides characteristic of this region have actually maintained the diversity of the coral reef; these low tides prevent one species from monopolizing the area. The temporal reproductive isolation of these coral species have also led to high diversity. The most abundant species breed at different times of the year- the case is the same for more minor species as well. Another reproductive mechanism that allows for the large amount of diversity is that the majority of species reproduces during the same time that benthic algae disappears each year. Because space on the reef is an issue, this seasonal disappearance allows for the coral to reproduce and spread out.
Sadly, many of the reefs, like in Eilat, have a tormented history of destruction and degradation. 50 years ago, the reef was much larger than it is today. The reefs have been destroyed over the past three decades, and especially over this last decade. Two events in particular have contributed to the degradation of the reefs in Eilat: an extremely low tide in 1970 and chronic oil spills from 1970-1980. The low tide caused the water level to drop 20-25 cm below the reef flats, exposing the reef to the air and sund for 3-4 hours during the hottest time of the day. This ultimately led to the destruction of 80-85% of the corals. During 1970-1980, oil tankers were causing 2-3 large-scale oil spills each month, completely blackening the reef! Thankfully, since this dark period oil spills have become rare, namely due to the major reduction of oil tankers arriving in Eilat, the establishment of a Pollution Prevention Control Station, and the large fines imposed on shipping companies.
Low tide.
Image taken from: http://www.coralworld.co.il/SiteContent/BankImages/690.jpg
Oil spill.
Image taken from: http://www.tampabay.com/blogs/alleyes/sites/tampabay.com.blogs.alleyes/files/images/typepad-legacy-files/1149.6a00d83451b05569e20133f12d0fd1970b-900wi.jpg
