Preliminary Survey of Coral Reefs at Vakare with special emphasis on Kayankerni Reef

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––– The present preliminary survey carried out several spot surveys on the reef using snorkel and SCUBA diving and carried out a rapid survey <strong>of</strong> reef areas using 2 divers on an 850meter long diver tow over the Eastern section <strong>of</strong> the reef <strong>at</strong> Thennadi bay. The areas were assessed for general habit<strong>at</strong> types, reef health indic<strong>at</strong>ors, and general Biodiversity <strong>of</strong> non-cryptic daytime fauna. the areas were documented using underw<strong>at</strong>er Photography and Video. The coral areas <strong>with</strong>in the Eastern section <strong>of</strong> the Thennadi bay is composed <strong>of</strong> three roughly fan shaped reef areas. The sections are diverse in habit<strong>at</strong>s ranging from large Staghorn coral domin<strong>at</strong>ed environments to massive Dome coral domin<strong>at</strong>ed habit<strong>at</strong>s to a varied combin<strong>at</strong>ions <strong>of</strong> mixed coral assemblages, <strong>Coral</strong> rubble zones and Sea grass beds composing a rich diversity <strong>of</strong> marine habit<strong>at</strong>s <strong>with</strong>in a compact area. The rich diversity <strong>of</strong> coral species is encountered <strong>with</strong>in the many coral habit<strong>at</strong>s. including Acropora, Porites, Montipora, Echinopora, Pocillopora, Favia, Favites A brief snorkel dive was carried out <strong>at</strong> the site known as the Sand Island which is loc<strong>at</strong>ed about 1.4km. <strong>of</strong>f the headland loc<strong>at</strong>ed on the Western end <strong>of</strong> Thennadi bay. the reef is a elev<strong>at</strong>ed out crop roughly 500m. x 300m. and ranging from almost intertidal sections and reaching down steeply to a depth <strong>of</strong> over 10m. the reef is composed <strong>of</strong> different habit<strong>at</strong>s including Staghorn domin<strong>at</strong>ed to large dome habit<strong>at</strong>s. The area is prone to high surf. On a general note the condition <strong>of</strong> the reef seem to be healthier than most comparable reefs <strong>with</strong> very low incidence <strong>of</strong> invasive organism activity and physical pollution. recent mechanical damage including human activities was not significant. coral areas are diverse and range from large Staghorn coral domin<strong>at</strong>es environments <strong>with</strong> more than 80% coral cover to mixed coral habit<strong>at</strong>s which are usually composed <strong>of</strong> mixed strands <strong>of</strong> several different Staghorn Acropora species including A. formosa and A. yongei. Large Dome coral environments <strong>with</strong> massive coral heads th<strong>at</strong> are commonly over 3m in high
and 4m. across are found in some reef edge areas giving excellent height relief to the reef and supporting large popul<strong>at</strong>ions <strong>of</strong> shoaling fish species above the colonies and in the deep crevices <strong>at</strong> their bases. In some areas large sections <strong>of</strong> old dead coral is found interspersed <strong>with</strong> live coral areas, significant areas <strong>of</strong> <strong>Coral</strong> rubble also exist indic<strong>at</strong>ing th<strong>at</strong> the reef may have seen a significant mortality event and is now recovering well from it. The age <strong>of</strong> corals vary and most are m<strong>at</strong>ure colonies indic<strong>at</strong>ing healthy long term survival <strong>of</strong> corals <strong>at</strong> the site. At least one large expanse <strong>of</strong> Sea grasses ( Halophilla sp.) was observed <strong>at</strong> about 5m depth. reportedly several other large sea algal beds are found in the area. At first the fish popul<strong>at</strong>ions seem abundant and diverse on the reef. The reef teems <strong>with</strong> large shoals <strong>of</strong> Fussiliers, Damselfishes, Cardinalfishes, Sweepers, Parrots, Snappers and Sweetlips. The initial impression <strong>of</strong> high abundance and the vibrancy <strong>of</strong> the fish popul<strong>at</strong>ions was shadowed by the notable lack <strong>of</strong> many species <strong>of</strong> "Color fish" th<strong>at</strong> would normally be expected to be present in a similar situ<strong>at</strong>ion. The group include many species <strong>of</strong> Butterflyfish; the family <strong>of</strong> which only 12 species were observed during the preliminary survey while in a reef <strong>of</strong> similar condition it would not be un-usual to find 20-25 species. In addition; many other species including Genera Pterois , Zebrasoma , Canthigaster, Ostracion, Amphiprion, Chromis, Plectorhinchus, Labroides, Dascyllus, Balistapus etc. were either not observed or found in very small numbers on the reef. While the preliminary n<strong>at</strong>ure <strong>of</strong> the dive is too brief for conclusions the apparent reduction <strong>of</strong> popul<strong>at</strong>ions may be <strong>at</strong>tributed to selective collection in the Ornamental aquarium industry. Other notable omissions included top end pred<strong>at</strong>ors including Trevallys (Carangidae),Barrakuda ( Sphyraenidae) and Large Groupers (Serranidae). medium to small sized groupers were common on the reef including E. caeruleopunct<strong>at</strong>us, C.argus, C.formosa. A very young individula and a medium adult grouper <strong>of</strong> a Plecropoma sp. was observed but was unable to confirm species identific<strong>at</strong>ion. Angel fishes were abundant <strong>with</strong> all three common large species (Pomacanthus semicircul<strong>at</strong>us, P. annul<strong>at</strong>us, P. impar<strong>at</strong>or) observed along <strong>with</strong> Centropyge multispinis, C. flavissimus and C. eiblii present. The focus on invertebr<strong>at</strong>es was low as the preliminary n<strong>at</strong>ure <strong>of</strong> the survey did not have scope to look for the more cryptic species. <strong>Coral</strong> abundance and Diversity was high and is documented in the list. The list only details species th<strong>at</strong> are easily identified in the field <strong>with</strong>out delving in to microscopy. Where it is not possible to go down to species level identific<strong>at</strong>ion has been carried out to generic level. The absence <strong>of</strong> any large sea anemones was notable and can be directly <strong>at</strong>tributed to the high activity <strong>of</strong> the ornamental fish collectors in the area. Few crustaceans were observed primarily due to the limit<strong>at</strong>ions in the preliminary survey observ<strong>at</strong>ions. Several Painted Spiny lobsters <strong>of</strong> medium size was observed along <strong>with</strong> good numbers <strong>of</strong> Sea cumbers still popul<strong>at</strong>ing reef areas. the sea cucumbers observed all belonged to the genus Holothuria while it may be possible th<strong>at</strong> a higher diversity would be observed if a night time survey is carried out. though several large Pin cushion Sea stars (Culcita spp) were observed It is notable th<strong>at</strong> no coral pred<strong>at</strong>or "Crown-<strong>of</strong> Thorn Sea stars" th<strong>at</strong> have reached plague proportions in many other reefs both in the East and North-west coast were observed during the survey. Crinoid popul<strong>at</strong>ions were abundant and Diverse. The Big Blue Octopus, Reef Squids, Large Lambis lambus
Page 1 and 2: Preliminary <stron
Page 3: Kayankerni reef The area was a long
Page 7 and 8: Sallativu/Sallithi
Page 9 and 10: Sand stone reef at
Page 11 and 12: Caesionidae Pterecaesio chrysozona
Page 13 and 14: Enneapterigius sp. 1 Blenniidae Pla

Preliminary Survey of Coral Reefs at Vakare with special emphasis on Kayankerni Reef

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