[Coral-List] Strange algae reported by divers

[Abigail Moore]

Dear Bastiaan

I am not entirely sure but this looks very similar to the sort of blue-green algae (people here call it "lumut") which often covers large areas of coral reefs (and other benthic cover - whatever is there) in Palu Bay and which we have also seen in some areas of Tomini Bay during periods of hot calm weather, especially near nutrient sources (e.g. household waste/sewage or intensive rice-farming areas). It seems to be especially prevalent near the outlet of the powerplant cooling water in Palu Bay. Colour can be grey to black, purplish (from almost black to sometimes quite bright purple) or dark greenish. It can spread very rapidly and usually also disappears quite rapidly when the weather changes. Some of the corals covered bleach and die but most seem to recover although they can be rather pale at first when uncovered again. However this short-term smothering did seem to seriously impede the recovery of reefs where most corals were still juveniles
 after  severe COTS attacks in Palu Bay.


All the best


Abigail

Abigail Moore
Sekolah Tinggi Perikanan dan Kelautan (STPL)
Palu, Central Sulawesi, Indonesia


Message: 1
Date: Thu, 28 Feb 2013 19:57:44 +0100
From: Bastiaan Vermonden <bastiaan.vermonden at gmail.com>
Subject: [Coral-List] Strange algae reported by divers
To: coral-list at coral.aoml.noaa.gov
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Dear Coral-listers

I just came across this question in a linkedin discussion group and thought
I could pose the question here:

"
*Need help identifying this strange black algae looking species growing on
corals in the Philippines. *

This picture was sent to myself as the regional Coordinator of Green fins.
We often get our members sending in strange e-mails but this one has really
got us stuck. It is very fast growing and resembles a smothering blanket
that is covering coral reefs in the Philippines. It is starting to concern
many divers who are seeing more and more of it specifically in the Moalboal
region of Cebu.
http://greenfins.net/Content/Uploads/Unknown%20black%20species.jpg?goback=%2Egmr_49850%2Egde_49850_member_218294623
"
Maybe someone from the coral list is familiar with this phenomena?

Regards,

Bastiaan Vermonden
http://diveselector.com