[Coral-List] Biodiversity extinction (Rodrigo Bustamante)

Rodrigo.Bustamante at csiro.au Rodrigo.Bustamante at csiro.au
Tue Feb 2 00:52:44 EST 2010


Just to point to our recent paper on the subject (ref and abstract below), and of course in the Galapagos, again! Not only this work document global and local extinctions, but also functional extinction on habitat forming species. What did happen with associated biota, no one knows, yet.
As stated by others, marine global extinctions are likely to be more common than our narrow views suugest simply because we are not aware of them due to lack of baseline data, insignificant local/regional monitoring and our meager surveying investment efforts....and btw, is so hard to prove it too.....

The local and functional extinctions are by far more pervasive and we should invest more in those fronts.

Saludos, Rodrigo.
Dr. Rodrigo H. Bustamante
CSIRO Marine & Atmospheric  Research 
PO Box 120, Cleveland, 4163, AUSTRALIA
Tel  61-7-3826-7310  Fax 61-7-3826-7222
Mobile 0408195273 Skype: RHBustamante

Edgar et al. (2009) El Niño, grazers and fisheries interact to greatly elevate extinction risk for Galapagos marine species. Global Change Biology doi: 10.1111/j.1365-2486.2009.02117.x

Comparisons between historical and recent ecological datasets indicate that shallow reef
habitats across the central Galapagos Archipelago underwent major transformation at the
time of the severe 1982/1983 El Nin~o warming event. Heavily grazed reefs with crustose
coralline algae ('urchin barrens') replaced former macroalgal and coral habitats, resulting in
large local and regional declines in biodiversity. Following recent threat assessment workshops,
a total of five mammals, six birds, five reptiles, six fishes, one echinoderm, seven corals,
six brown algae and nine red algae reported from coastal environments in Galapagos are now
recognized as globally threatened. The 2008 International Union for the Conservation of
Nature (IUCN) Red List includes 43 of these species, while two additional species (Galapagos
damsel Azurina eupalama and 24-rayed sunstar Heliaster solaris) not seen for 425 years also
fulfil IUCN threatened species criteria. Two endemic species (Galapagos stringweed Bifurcaria
galapagensis and the damselfish A. eupalama) are now regarded as probably extinct, while
an additional six macroalgal species (Dictyota galapagensis, Spatoglossum schmittii, Desmarestia
tropica, Phycodrina elegans, Gracilaria skottsbergii and Galaxaura barbata) and the
seastar H. solaris are possibly extinct. The removal of large lobster and fish predators by
artisanal fishing probably magnified impacts of the 1982/1983 El Nin~o through a cascade of
indirect effects involving population expansion of grazing sea urchins. Marine protected areas
with adequate enforcement are predicted to ameliorate but not eliminate ecosystem impacts
caused by increasing thermal anomalies associated with El Nin~o and global climate change.

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