October 25, 2016

Oman's Musandam Coral Reefs Weather El Nino

By Biosphere Expeditions

Despite high salinity and water temperatures, even more extreme in the recent El Niño year, Oman's Musandam Peninsula's coral reefs are thriving, according to a recent Reef Check survey conducted by Biosphere Expeditions. Divers observed coral cover ranging between 28 and 78% at shallow (<10m) depths, with little evidence of coral disease, predation, or bleaching. However, the report cautions that additional stress caused by natural or anthropogenic impacts could severely affect coral and other ecosystems, as has been seen in other reefs in the Arabian Peninsula. Additionally, fisheries in the area have undergone a decline. Biosphere Expeditions thus urges the establishment of a number of no-take zones in the northern part of the Peninsula.

The Musandam Peninsula is located at the northernmost point of Oman, at the entrance to the Arabian Gulf, and is in fact separated from the rest of Oman by part of the United Arab Emirates. The 650-mile coastline is characterized by rocks, coves, and steep cliffs and slopes, and the coral reefs remain relatively untouched by human intrusions such as industrial fishing and recreational diving. The reefs face a different challenge in the form of high salinity and temperature. Though moderate in comparison to the Gulf of Arabia, the Gulf of Oman still experiences summer water temperatures between 23 and 31°C, with a maximum temperature of 35°, but due to a strong thermocline this range can be experienced over the course of a single day. Salinity is generally at 36.5% with recorded extremes of 38.9%. Oman's coral reefs have thus been uniquely adaptable, with a resultant variety of coral habitats in the area.

During the last week of October 2015, Biosphere divers used Reef Check methodology to survey eight different dive sites along the northern Musandam coastline. “Corals appeared to be in a healthy 'climax' state on many of the shallow reefs, with many sites hosting very large Porites colonies, indicating no significant damaging events to these corals over the past 400 years,” according to the report.

However, high densities of Diadema urchins are causing structural damage to the reef structure, though no grazing pressure was observed. Additionally, the reduced size and abundance of grouper populations, and the sighting of only one lobster, point to pressures of local fishing. The report expresses concern that continued coastal development in the area will add to overfishing, and thus urges the establishment and enforcement of fishing regulations, as well as the designation of marine protection zones.

Click here to download the full report: www.biosphere-expeditions.org/images/stories/pdfs/reports/report-musandam15.pdf

For more information, please see www.biosphere-expeditions.org/oman.