The area of reef at East Island was a
fringing reef flat which varied between sandy patches, large coral patches, gentle slopes with
strips of reef running along the length of island, scattered bommies and ridges of reef running outwards from
the island
at all the different places we dived.
Hard coral coverage varied between the different areas, changing between 5
and 30%. This was a very diverse reef - Acropora, Porites, Lobophyllia,
Turbinaria, Echinophyllia and Montipora dominated, each
in a certain area. We also witnessed intense competition between coral
colonies in some areas. The main factors affecting the health of the corals
were
overgrowth by coralline algae, macroalgae and filamentous algae, particularly
Halimeda and Valencia, some areas with 80% cover. There
was also some invertebrate overgrowth. All these conditions were
observed on each dive. It was apparent that this was an old
reef and there were large colonies present of the dominant hard corals
including a Lobophyllia 2m across and large
columnar
Acropora. There was some bleaching an Astreopora at approximately 18m,
also noticeable was the base of some branching Acropora had died off
although we are not sure of the cause.
Reef fish were diverse but not plentiful. Many large commercial fish were
absent but there were many small
reef fish. Throughout these dives we sighted unicornfish, snappers, bluefin trevally,
moustache
triggerfish, several large coral hind, jobfish, emperors and a few enormous
barracuda. Also observed were plentiful and diverse wrasses, abundant
lizardfish along with blue line fusiliers, pipefish, lionfish, black-spotted pufferfish, yellow tailed poison
fanged blenny, many angelfish and butterflyfish, a 1.5m long wahoo, a
barramundi cod, gobies, Moorish idols, 8 enormous bumphead parrotfish, 3
rainbow runners swimming along beneath the divers. The divers also
saw a manta ray at 25m, a blue spotted ribbon tail ray and many garden eels in
the sand patches. Also sighted was a small white tip and a grey reef
shark which is nowhere near the numbers the ship saw when we dived here 3 years
ago.
There was between 20 and 60% soft coral coverage with some very large
colonies and included Xenia,Lobophtium, Clavularia,
Sarcophyton,
Lemnalia, Sinularia,
Dendronephthya, Paracemnalia, Acabaria, Scleronephthya,
Heteroxenia,
Capnella and Imbricata. Some of the colonies were very large.
Invertebrates included giant clams of Tridacna maxima, Tridacna squamosa
and Tridacna
derasa some of which were extremely large. Five were betweenn 1 - 1.5m in
length and approximately 12 between 10-50cms. Altogether 6 nudibranchs
were seen including Phyllidiella, also 2 sea cucumbers including
Synaptula
lampert and Thelenota anax at 120cm. Corallivorous snails,7
oysters, cone snails, hundreds of bioeroding snails and Luffariella covered
in tiny red crabs. Also hydroids, crinoids, brittlestars on Acropora.
There were many spaghettii worms, fan worms, ascidians with many colonies of
Didemnum molle and several
diadem sea urchins. Barrel sponges were large and abundant. There were many
tunicates,1 giant whip coral, vast black sponges and large anemones with
anemone fish.
During all dives here the current varied and was stronger near the surface
in the first few metres. Generally visibility was poor due to a lot of
plankton in the water and overcast skies. The water temperature was 29°C.
This was a platform reef with a gradual 45 degree slope that became steeper
in the deeper zones to a sandy bottom with coral rock patches and scattered bommies.
This area of reef had
10-15% hard coral coverage with Acropora, Porites and Echinopora
dominating but this was a very diverse reef and the corals were
generally healthy. There was some bleaching of Porites and Leptastrea at
approximately 5m and white band disease was observed on
an Acropora. Some areas looked like they had been demolished with overturned Acropora
tables which was possibly due to trawling lines. Generally there was
a 10% coverage of algae particularly Halimeda and some coralline
algae,
however coverage was very high in some areas and there was a low cover of soft coral.
There was a low abundance but good diversity of fish which included green jobfish, rainbow
runners, lots of damsels in Acropora tables, some large sweetlips,
2 dogtooth tuna, many hawkfish, 20 batfish, schools of different unicornfish,
wrasse and trevally species, a small school of fusiliers, a school of
juvenile tuna, a blue spotted ribbontail ray eating in the sand and other
typical small reef fish. There were also some surprises with a school of
midnight snapper of 200-300 fish and 2 separate schools of barracuda. We
saw no live sharks, however one diver unfortunately saw 3 small dead finned sharks, 2
of which had been skinned. They looked to have been killed recently
by shark finners because they had not begun to decompose or been eaten by
scavengers. This was a sad sight for some people on the Heraclitus who
had dived here three years ago and seen an ecosystem full of sharks and
many fish. Since that time the area has been found by local fishermen who
have taken almost all the large fish which have been used as bait to
catch the sharks, almost all of which have been removed.
Approximately 12 giant clams were sighted all between 10-80cm and
included Tridacna squamosa, Tridacna maxima and Tridacna gigas.
Also sea
cucumbers, feather stars and 1 trochus shell
The current varied between 0.5-3knot currents, visibility was 10 metres
due to plankton in the water.
We moved the ship to the western reef in hope of better news on the
state of the reef ecosystem in this area. Here we found the reef to
be a platform reef with a lot of rubble on the platform and a few
bommies. The slope had 25% coral coverage.
The corals here were very diverse particularly on the slope with Acropora and
Porites dominating. Also worth noting was a high abundance of
Pectinia on the slope. White band
disease was seen on some large Acropora tables, some other tables
were also broken and turned over and a pink spot disease was
seen on Porites. In one area on the slope there was a high concentration of
Halimeda, approximately 90% and on the platform there was a
40% cover of red filamentous algae.
The fish life here was a completely different story with a high
diversity and abundance .There were giant 2m dogtooth
tuna,2 enormous Spanish mackerel, 1 large grey reef shark
feeding and 4 smaller grey reefs, 2 whitetips, one of which zoomed
up from the sandy bottom as we ascended. On another dive there were
10 sharks consisting of black tip, grey reef and 1 nurse
shark. Swarms of schools of oceanic
trigger fish and unicornfish, over 200 of each, large school of
midnight snapper, approximately 20 large dog tooth tuna, schools of
rainbow runner and a school of 300 barracuda who mesmerized
the divers. Also sighted on these dives were
2 turtles, 1 female hawksbill turtle and 1 female green turtle.
More information on
these turtles can be found on our turtle log.
There was not a big soft coral coverage but Millepora
was dominant over the reef with 30% on the slope and 1% on the
platform. Invertebrates observed included 4 giant clams including
one Tridacna giganta at 85cm. Also 5 diadem sea urchins, 1 corallivorous snail on an
Acropora, 3 nudibranchs one of which was a
Chromodoris,
1 lobster, many vase shaped dark green sponges covered in brittlestars
and15 sea cucumbers all 10cm long.
We experienced
strong 2-3knot currents and it was hard to hold on to the surface
marker buoy because of
the even stronger
surface currents. Visibility was 30m.
.JPG)
a,
Turbinaria, Echinophyllia and Montipora dominated, each
in a certain area. We also witnessed intense competition between coral
colonies in some areas. The main factors affecting the health of the corals
were
overgrowth by coralline algae, macroalgae and filamentous algae, particularly
Halimeda and Valencia, some areas with 80% cover. There
was also some invertebrate overgrowth. All these conditions were
observed on each dive. It was apparent that this was an old
reef and there were large colonies present of the dominant hard corals
including a Lobophyllia 2m across and large
columnar
Acropora. There was some bleaching an Astreopora at approximately 18m,
also noticeable was the base of some branching Acropora had died off
although we are not sure of the cause..JPG)
tache
triggerfish, several large coral hind, jobfish, emperors and a few enormous
barracuda. Also observed were plentiful and diverse wrasses, abundant
lizardfish along with blue line fusiliers, pipefish, lionfish, black-spotted pufferfish, yellow tailed poison
fanged blenny, many angelfish and butterflyfish, a 1.5m long wahoo, a
barramundi cod, gobies, Moorish idols, 8 enormous bumphead parrotfish, 3
rainbow runners swimming along beneath the divers. The divers also
saw a manta ray at 25m, a blue spotted ribbon tail ray and many garden eels in
the sand patches. Also sighted was a small white tip and a grey reef
shark which is nowhere near the numbers the ship saw when we dived here 3 years
ago. .JPG)
n 1 - 1.5m in
length and approximately 12 between 10-50cms. Altogether 6 nudibranchs
were seen including Phyllidiella, also 2 sea cucumbers including
Synaptula
lampert and Thelenota anax at 120cm. Corallivorous snails,7
oysters, cone snails, hundreds of bioeroding snails and Luffariella covered
in tiny red crabs. Also hydroids, crinoids, brittlestars on Acropora.
There were many spaghettii worms, fan worms, ascidians with many colonies of
Didemnum molle and several
diadem sea urchins. Barrel sponges were large and abundant. There were many
tunicates,1 giant whip coral, vast black sponges and large anemones with
anemone fish..JPG)
nd scattered bommies.
nd and other
typical small reef fish. There were also some surprises with a school of
midnight snapper of 200-300 fish and 2 separate schools of barracuda. We
saw no live sharks, however one diver unfortunately saw 3 small dead finned sharks, 2
of which had been skinned. They looked to have been killed recently
by shark finners because they had not begun to decompose or been eaten by
scavengers. This was a sad sight for some people on the Heraclitus who
had dived here three years ago and seen an ecosystem full of sharks and
many fish. Since that time the area has been found by local fishermen who
have taken almost all the large fish which have been used as bait to
catch the sharks, almost all of which have been removed..JPG)
nurse
shark. Swarms of schools of oceanic
trigger fish and unicornfish, over 200 of each, large school of
midnight snapper, approximately 20 large dog tooth tuna, schools of
rainbow runner and a school of 300 barracuda who mesmerized
the divers. Also sighted on these dives were
2 turtles, 1 female hawksbill turtle and 1 female green turtle.
More information on
these turtles can be found on our turtle log.