[Coral-List] Re: Flameless, cost-free response
beliamall at dhivehinet.net.mv
Thu Mar 4 03:51:18 EST 2004
In some Maldive locations recovery of reefs reduced to less than 1% cover of
bleaching-susceptible corals in 1998, has been very rapid (some now have
100% cover). This rapid recovery has occurred close to reefs that for one
reason or another were relatively little affected by the bleaching. Reefs
farther removed from such sources are recovering more slowly (but the pace
is accelerating and there is no shortage of suitable hardground). This
suggests that recruitment from local sources is very important. Presumably
local sources could have been key in the example Mike cites also. Arguably
conservation with the greatest marginal return on the dollar is the
protection of such bleaching-resistant reefs from anthropogenic damage.
Decisions about the benefits of artificial reefs and coral transplantation
should include that opportunity cost in the calculation.
Rangas, Violet Magu
email: beliamall at dhivehinet.net.mv
On 04/03/02 17:54, "Michael Risk" <riskmj at univmail.cis.mcmaster.ca> wrote:
> Hello Jim, colleagues.
> I supported your original decision, with the proviso that I would like
> to see more sexually-explicit material on the list. I was struck,
> however, by your innocent mention of Nature taking her "slow" course.
> In this broad discussion of means towards reef rehab, it might be
> appropriate to set some upper and lower boundaries for recovery rates.
> We know, from Walter Adey's drilling work, that after a sea-level rise
> reefs will colonise the flooded coastline-AFTER about 1,000 years
> during which the silt etc is reworked out of the shoreline deposits. So
> those who blithely state that reefs will simply expand landward and
> up-latitude following any sea-level rise produced by icecap melting
> don't know what they are talking about. (Either that, or they are very
> patient people...hmm, close to flaming here...)
> So that's the upper limit: at least 1,000 years, following sea-level
> rise. Any future recolonisation would likely take longer, because the
> ocean would have to clean up all the condos and Cadillacs.
> At the lower end: Tom Tomascik has described reef initiation on a lava
> flow in the Banda Islands, Indonesia. From hot lava hitting the ocean
> (the local name for the site is Air Panas-"Hot Water") to 100% cover by
> mostly acroporids was about 5 years. Of course, the human population
> density is almost zero, and the water is dead clean.
> Perhaps this puts the "need" for artificial substrates into
> perspective. We shouldn't need them.
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