Back from Fiji
fpl10 at calva.net
Sun Jun 20 03:28:43 EDT 1999
I'm just back from Fiji, and some of you asked me to provide some data, so
here are some.
- The following comments are only based on observations I did (with almost
no tools other than my deep meter, temp meter, and my reef aquarist & Diver
- They are only relevant for the Rainbow reef (between Vanua Levu & Taveuni
islands), because I didn't have the chance to dive elsewhere.
- These information have been gathered during 20 dives and by talking to
- This report is for the period 5/06/99 - 17/06/99
- About coral problems reported below, I assume the following, based on my
- a white coral skeleton implies a death since less than 1 week
- a light yellow coral skeleton implies a death between 1 and 2
weeks (yellow color is given by growth of small filamentous algae)
Overall report :
- The Rainbow reef seems to suffered a lot during the last hurricanes : 40%
of the dive sites have been distroyed, some were displaying large colonies
of Turbinaria reniformis (more than one meter high). However, according to
divers I met and that were also in Fiji 3 years ago, it seems that this
reef has improved (more corals, more bigger fishes)
- I have seen the following corals problems on every sites I went :
* Acanthaster planci : some sites (like the LEDGE) are highly
attacked. I would say that 20% of the hard corals have been parlty or
completely attacked in less than 2 (?) weeks (many skeletons still show a
pure white color). Some Professional Divers try to slow down this problem
by manualy removing Acanthaster from the reef each time they can.
* (R)TN : Aside the Acanthaster attacks, I have seen what I called
(Rapid) Tissue Necrosis, with a Question Mark on "Rapid" because the only
clue I have to say that it's rapid is the skeleton color (pure white). I
have to say that I have seen Snails' Attacks also, but their impact seems
to me different than what I have seen. So, many species are suffering from
this (R)TN, which can be described by a loss of tissue starting from the
base of the small polyped colonies :
- Seriatopora histrix (highly suffering)
- Acropora sp (highly suffering)
- Pocillopora sp
- Stylophora sp
- Herpolitha limax
- Distichopora & Millepora (28 m depth)
- Tubastrea micrantha
on some sites, some colonies have stopped their (R)TN (white skeleton was
no more visible). I would say that (R)TN started early May 99. There was no
WBD, RBD, BBD visible on these colonies...
* Bleaching : Many species are partly or completly bleached.
However, bleaching is very low compared to (R)TN and Acanthaster attacks,
and only few colonies are showing a bleaching :
- Montipora danae
- Acropora sp (only on a site in shallow water (less than 10 m
depth) just near the cost : the rains could be the cause)
- Platygyra daedalea (shallow reefs)
- Sinularia (20 m depth)
The water temp was 26-27° C. It was raining quite often. The visibility is
often equal or under 15 m.
- Sites show between less than 5% to 100% coral coverage on shallow parts
(10 to 4 m depth). On some sites, many new hard coral colonies (Acropora,
Pocilloporidae, Montipora, Porites,...) are visible (meaning less than 10
cm high). On a old dead Acropora table, 1 meter square, I counted about 15
different young colonies.
- high growth rate on SPS is visible, according to tips color.
- 1 site has been reconstructed 5 years ago by a biologist => Acropora
colonies are now 1 meter high and are covering hundreds of square meters.
I've been a bit disappointed by the sites I have seen. I would have bet
that they were amazing, but despite a Great SPS diversity in some (few)
sites, I found them less rich than what I have seen in Philippines for both
Fish and corals. But this conclusion could be false for all the other reefs
of Fiji !!
I'll have soon some underwater photos developped that show (R)TN and
bleaching, for the ones who want them.
If some of you can explain to me what could be the cause of the (R)TN I saw
in Fiji, but also in other countries, that would be great !
Hope this helps
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