In geological terms, the emirate's modern coastline is
extremely young - just 4,000 years old. In that time, somehow its corals have
managed to beat the heat. So has that been a slow process, creating a stable
local stock of heat-resistant corals, or dose each generation in turn find its
own way of coping. The coral live in symbiosis with zooxanthellae, a type of
algae that lives inside the coral's tissue. The algae photosynthesise,
producing sugars that provide up to 90 per cent of the coral's energy, and in
return, the coral provides shelter, nutrients - mostly nitrogen and phosphorus
- and carbon dioxide for photosynthesis. Such a cosy arrangement is not without
pitfalls. So co-dependent are the two species, that if one dies the other is
unable to feed itself to stay alive, leading to coral bleaching. And 2010 was
hot, too, with water temperatures in the Gulf exceeding 37°C. Corals were lost
on many reefs in the southern basin of the Gulf, the waters between Qatar and
Dubai.
Corals reproduce in
one of two ways: through fragmentation or larval production. Fragmentation, is
when a piece of coral breaks off, rolls across the sand, lands somewhere else
and starts growing. The slow rates of recovery suggest that the problem is not
larval production, but more the harsh environments the larvae find when they
land. And with the water already so hot, the corals are at the thresholds of
their tolerance, so even slight increases in stress can push them over the
edge.
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