Bamboo coral like this can live to be more than 200 years old. Note the faint red laser dots at the four o'clock and ten o'clock positions. These give us a measurement scale (29 cm) for everything we collect. Click image for larger view and image credit.
Bamboo coral is added to the bio box on the sled of the ROV. Samples of bamboo coral are placed in the slotted section so we can tell one individual from another. Other species are put into the larger box at the right. Numbered push cores on the front of the drawer are used to collect sediment samples. Click image for larger view and image credit.
Recovering Coral Samples
January 29, 2006
Allen Andrews
Radiochemist
Moss Landing Marine Laboratories
California State University
As we flew the ROV Tiburon from the floor of "Big Valley" up a slope of jumbled basaltic rock, we came upon small stands of bamboo coral. I was excited to see them because collecting samples of this large coral is my main objective for this expedition. Prior to sampling the bamboo colonies we took a series of photographs of each colony. In each photograph we placed a set of lasers separated by a known distance (29 cm). This will allow us to know how big the colonies were prior to sampling. For each colony I wanted to get two small branches. This was accomplished using the robotic arm by carefully reaching in to snap off a small limb. Each limb was placed in a special file-like box to keep track of the colony and location from which the sample came. We managed to collect samples from 4 colonies in two different locations this day. Over the next few days I plan to sample in the same manner at two more locations on Davidson Seamount.
In addition to collecting bamboo coral samples, I am interested in other species. Specifically, I did some age and growth work on a pink coral (Corallium sp.) colony collected in 2002 from Davidson Seamount. I determined that this 30 cm colony was more than 120 years old and could be as old as 200 years. While searching for bamboo corals yesterday, we discovered that pink coral is very common on a hill we later called "Corallium Cap". While in this area we carefully collected a full pink coral colony attached to a rock. This coral is very brittle, but the skilled handling of the ROV pilots made an intact collection possible. This specimen is currently stored in the freezer and will undergo more precise age determinations back at my lab at Moss Landing Marine Labs.
We were able to pick up this colony of pink coral still attached to a rock without breaking any branches. The manipulator claw is about 9 inches long but MBARI's skilled ROV pilots can pick up items as small as a dime from the seafloor. Click image for larger view and image credit.
Pink Corallium corals along the flank of the hill we named "Corallium Cap" just to the east of "Big Valley." Click image for larger view and image credit.
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