[Coral-List] Algae and nutrients and herbivory in oligotrophicwaters
dfenner at blueskynet.as
Sun Jun 22 17:03:28 EDT 2008
Thanks for the more accurate info on Male, Bill! I had gotten my impression from a previous posting some time back, never been there. Doug
----- Original Message -----
From: William Allison
To: Douglas Fenner
Cc: coral-list coral-list
Sent: Sunday, June 22, 2008 8:35 AM
Subject: Re: [Coral-List] Algae and nutrients and herbivory in oligotrophicwaters
Doug - Unless the situation has changed radically since April 2007, and depending on what is meant by "tons of algae" I may disagree with your statement (1) about Male but not with your general thesis. On the reef surrounding Male, algal turf is abundant but not particularly luxuriant, macroalgae scarce except for Halimeda and sometimes Dictyota (which comes and goes in Male and elsewhere), corals are sparse and tend to cycle through pretty quickly, and bioerosion is considerable - probably because the dissolved and particulate nutrients favour algae and borers which are in turn consumed by the many secondary bioeroders feeding on them. I suspect that if grazing pressure was relaxed algae would become a much more important component of benthic biomass but for the time being grazing seems to be controlling it to some degree - at a price to the reef.
(1) "I find the observation that there is tons of algae around Male in the Maldives where the people don't eat reef fish and there are plenty of herbivorous fish, but the city releases tons of untreated sewage, is a convincing demonstation of the effects of nutrients."
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