Nutrient deficiency and bleaching

[CRCP]

Debbie, Alina and co.

One interesting observation of the 98 bleaching in western Indian Ocean was
that the marine parks, which have a high biomass of fish, experienced the
highest mortality through bleaching (McClanahan et al. 2001).  This is largely
attributable to the fact that Acropora is more abundant in the parks where as
it seems to be damaged by nets, coral collection and other things outside of
the park.  Also the the very pristine and unfished Maldives and Chagos Islands
experienced terrible bleaching in 98 (Goreau et al. 2000, McClanahan 2000,
Sheppard 1999).   So, these findings would support Alina's contention that
fishing and bleaching effects are not influenced by fish abundance through any
nutrient interactions, but that fishing does affect coral abudance through
direct damage (breaking, collecting..) but also through predator-prey
interactions that  influence bleaching by influencing the abundance of
bleaching and non-bleaching sensitive corals.  Branching corals are most
susceptible to bleaching and also from damage and collection, consequently
parks can increase the abundance of these species and produce the most
dramatic losses when bleaching occurs.


Goreau, T., T. McClanahan, R. Hayes, and A. Strong. 2000. Conservation of
coral reefs after the 1998 global bleaching event. Conservation Biology
14:5-15.

McClanahan, T.R. 2000. Bleaching damage and recovery potential of Maldivian
coral reefs. Marine Pollution Bulletin 40:587-597.

McClanahan, T.R., Muthiga, N.A., Mangi, S.  2001. Coral and algal changes
after the 1998 coral bleaching and mortality: interaction with reef management
and herbivores on Kenyan reefs.  Coral Reefs 19: 380-391

Sheppard, C.R.C. 1999. Coral decline and weather patterns over 20 years in the
Chagos Archipelago, Central Indian Ocean. Ambio 28:472-478.


Tim McClanahan
Coral Reef Conservation Project
The Wildlife Conservation Society
Kibaki Flats #12
Kenyatta Beach, Bamburi
P.O. Box 99470
Mombasa, Kenya
email: crcp at africaonline.co.ke
Tel O: 254 11 485570
Tel H: 486549



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