By Reef Check Executive Director Dr. Gregor Hodgson
A team of eight Reef Check scientists surveyed 50 reefs in the vicinity of Sharm El Sheikh, Egypt in May 2010 to determine what condition the reefs were in with respect to ecological health and carrying capacity. Carrying capacity has been defined in a couple of ways: ecological and social. Ecological carrying capacity is exceeded when additional visits by divers damage the ecology of the reefs whereas social carrying capacity is exceeded when additional visits by divers produce a reduced quality of the experience for the visitors to an area.
This area of the Red Sea has been high on the list of “must see” diving sites since the 1970s. At that time, Sharm was advertized with a “money-back” guarantee to see a shark on every dive. But the demographic has shifted from a few thousand highly trained scuba divers in those early years to over 3 million sun and fun snorkelers and inexperienced divers in 2009. Almost 400 dive boats carrying up to 60 passengers each target about 40 official dive sites. Over ten years ago, scientists familiar with the area predicted serious damage to the reefs as tourism ramped up. But based on the Reef Check surveys, other than sharks and most large predatory fish missing in action, the reefs are healthy. In fact, Sharm is one of the few places in the world where a Napoleon (Humphead) Wrasse – a key Reef Check indicator species – can be seen on almost every dive. The clear water, colorful corals and walls that drop down 100s of meters are sensational. Given the lack of predators, the populations of brilliant red-orange Anthias are probably the highest in the world. The low populations of large giant clams were a puzzle until a local biologist pointed out that they are a favored target of free diving Bedouin tribes who still live along the coast (Fig 1).
As it turns out, the homogeneous structure and composition of the reefs of Sharm El-Sheikh provide some natural protection that is not found elsewhere and that has allowed a huge flow of tourist swimmers, snorkelers and divers to coexist with the reefs without destroying them. Three main features explain this:
- The shallow reef flats are so shallow that snorkelers realize that they are likely to be “scraping bottom” if they try to squeeze in over the reef (Fig 2).
- The reef flat ends in a 90 degree drop off that is covered in branching Millepora fire coral so snorkelers who bump up against it get a nasty sting if they are not completely covered (Fig 3).
- The drop off is typically so steep and covered with sharp appearing corals, that snorkelers and divers can maneuver to avoid it.
Aside from some occasional broken corals and the lack of large predators due to regular fishing, the reefs are still in amazingly good condition when one considers that some individual reefs are visited by more than 1000 people per day. Reef Check will be continuing to work with the authorities in Sharm El Sheikh to come up with plans to help spread some of these impacts and reduce the number of visitors to some reefs and control fishing. But at a time of lots of bad environmental news, the situation in Sharm was a pleasant surprise. Reef Check would like to thank biologists Christian Alter of Red Sea Environmental Centre, Dahab, Melanie Koch, Nina Milton, Dr. Moshira Hassan, Pascal Kriwy, and Anna Roik, as well as Petra Röglin and Rolf Schmidt of Sinai Divers, the crew of the Ghazala boats and to Stephan for photos during the successful survey week.
|Figure 2. The reef flat is extremely shallow and flat, and then drops abruptly in a vertical wall that normally reaches 15 to 20 m depth. The coral living on the reef flat must be highly resistant to extreme environmental changes in salinity, temperature, and even exposure to the air during extreme low tides.|
Figure 3. The reef flat is extremely shallow and flat, and then drops abruptly in a vertical wall that normally reaches 15 to 20 m depth. The coral living on the reef flat must be highly resistant to extreme environmental changes in salinity, temperature, and even exposure to the air during extreme low tides.