Ahoy! Another day of research for BIOL 403 on coconut islands HIMB!
Bay exploration for L.reevii distribution continued with the group performing analysis on fringing reef B3. The bottom became muddy after a short jaunt over the reef edge covered with the coral species Porites lobata and Montipora capitata. There was plenty of swimming as well as our transects appeared deep in the shallow where the boat could not go.. In the areas surveyed by our two groups only two L.reevii were found nearest to the southwestern edge of the reef. In these areas the typical invasive algal species Kappaphycus alvarezii and Gracilaria salicornia were present in high amounts along with the ubiquitous Opheodesoma spectabilis (sea cucumber). We found a yellow and blacked stripped fish friend as well (unidentified, refer to pics).
The next area the crew travelled to was reef 15, proximal to the green channel marker #14 in the middle of the Bay a couple kilometers offshore. The varieties of corals were surprising, with the crew tentatively identifying Fungia scutaria, Montipora flabellate, Montipora capitata, Montipora platula, Porites lobata, Porites compressa, Pocillopora damicornis, Pocillopora meandrina just by a first glance. Fish species seen included Euprymna scolopes, Gymnothorax javanicus (Giant Mooray eel), Fistularia commersonii (cornet-fish), and Thalossoma duperrey. Several L.reevii burrows were spotted in a small 20m x 10m sand patch in an informal survey.
The Montipora dilatata groups continued there surveying at reefs 44 and 47. Additionally, reading devices for temperature and irradiance (light), known as HOBO (Honest OBserver by Onset) were deployed at each site (block in pictures) . Today, the groups had a more smooth operation and found out some new techniques on pH analysis.
In the evening, Nyssa Sibliger was kind enough to discuss the balance of coral reefs. The symbiotic relationship between coral and symbiotic algae was discussed. Coral organisms provide carbon and inorganic nutrients symbiotic algae which in turn provide oxygen and inorganic compounds for corals. Reef accretion is the ratio of coral growth to reef erosion. Agents of reef erosion include micro borers, macro borers, and coral grazers. The bio eroding communities change per location; inner reefs are dominated by micro eroders while the outer reefs are dominated by coral grazers. These different eroding agents alter physical structures of different reef species.
The best predictor of reef erosion however is the surrounding pH. The lower the pH, the more rapid the skeletal structure is eroded. Nutrients and depth, on the other hand, are not important in the rate of structural erosion along a natural gradient. Lastly, medical tests which determine bone density are efficient in determining coral density and erosion rates.
Next…was dinner! Baked rosmary chicken and potatoes made by our lovely cohorts, Ally and Taylor! Sweet, simple and deeeelicous! Then it ws time to cram all our data into our computers and prepare for the next day! It just gets better and wetter everyday!
A hui hou!