Status of Coral Reefs of the World 2000

Status of Coral Reefs of the World: 2000
STATUS OF CORAL REEFS
Bahrain
The main coral reefs are limited to a few areas in extreme environmental conditions. Coral
cover is generally low, with evidence of recent, widespread coral mortality. These coral
communities are at the very limits of tolerance to salinity, temperature, and sediment load,
but there are 28 species of coral in Bahrain. The reefs recently experienced two major coral
bleaching events: summer of 1996; and more severely in the summer of 1998. These events
resulted in the complete mortality of corals on Fasht Al Adhom, west Fasht Al Dibal, Khwar
Fasht, north Jabari, Samahij, and Fasht Al Jarim. The only live coral reef surviving in Bahrain is
on Abul Thama, a small raised area surrounded by 50m deep water about 72km north of
the main island. In addition to coral bleaching in 1996, a large fish kill was reported in Ras
Hayan lagoon.
Sea surface temperatures of 38 o C were recorded in 1998 on Hayr Shutaya, about 30km
north of Bahrain, and coral bleaching followed with morality between 85-90% of Fasht Al
Ahdom, Jabari, Samahij, and Fasht Al Dibal. In 1996, corals were 100% bleached at Fasht Al
Adhom, and 40% bleached (with 40% dead coral cover) at Jabari. At west Fasht Al Dibal
there was 80% bleaching, and at Abul Thama corals were 33% bleached, with 33% dead
coral cover. About 95% of the corals were dead on the Half Tanker wreck on Fasht Al
Adhom by late-1996. On Abul Thama the hard corals on the seamount (which comes to
8m of the surface) were in better condition, because they are surrounded by 50m deep
water. The cover of hard coral has remained relatively stable (25–35%), with a greater
diversity of key invertebrate and fish species than Fasht Al Adhom.
The major direct anthropogenic factors impacting on corals in Bahrain are commercial trawl
fishing, dredging and land reclamation, with little consideration given to maintaining the
environment. Prior to 1998, there were about 300 artisanal shrimp trawlers and 6 larger fish
trawlers, which often poached in shallow waters around the coral reefs. The reappearance
of small soft corals and crinoids on Bahrain reefs is linked to the 1998 closure of the
industrial fishery. There are major industrial plants for electricity generation, water
desalination, oil refinery, aluminium refining, and for petrochemicals that discharge heated
seawater, which increases temperatures during the summer months. Land reclamation on
the northern and eastern coasts have increased the area by 11km 2 in less than 10 years,
often covering valuable coastal resources, but not yet directly impacting coral reefs.
However, there are proposals to reclaim part of major coral reef areas at Fasht Al Adhom.
There are government regulations concerning land reclamation, but there is little
enforcement and compliance with these regulations, and many projects are completed
without government approval. Dredging is used to maintain navigation channels and collect
sand for reclamation and construction. About 10 suction dredgers routinely operate in
Bahrain waters, including specialised cutter and suction dredgers. During dredging
operations, large amounts of silt flow directly onto corals from Muharraq dredging area,
with about 182,000m 2 reef area lost between 1985 and 1992.
There was no regular monitoring of coral reefs in Bahrain until 1993, when a volunteer diving
program started with assistance from the Department of Fisheries. These surveys show an
almost total loss of live hard corals on Fasht Al Ahdom, with coral cover declining from 30-
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