Geoscience Reference
In-Depth Information
4.3.4 Coral reef ecosystems
A conservative estimate of the total area covered by coral reefs is 62,000 km
2
and the eco-
nomic value of all ecosystem services provided by corals approaches US$ 365 billion per
ats across the world, with coral bleaching, invasive species, and community shifts linked
coral reefs during periods of warmer than normal sea temperatures (Walther
et al.,
2002
;
Przeslawski
et al.,
2008
). Poised near their upper thermal limits, coral reefs have undergone
global mass bleaching events whenever sea temperatures have exceeded long-term summer
most severe period occurred in 1998, during which an estimated 16% of the world's reef-
cases branching acroporid and pocilloporid corals have bleached and/or died, leaving more
massive species like
Porites spp.
intact. In other cases, all coral species have largely been
ness and community structure have changed after bleaching events are generally not avail-
able, but such changes are suspected to be large. When coral loss has been severe, reef fish
loss of key species within critical functional groups, or the complete loss of entire functional