Greetings from the R/V Alucia! We just celebrated another birthday on board the R/V Alucia. Carlos, one of the ship engineers, just turned 75 years old today! This morning, the crew mess was decorated with balloons and birthday messages! After dinner, we sang Happy Birthday to him and enjoyed some delicious cake.ou
As you probably know, diving has been a major component of our work during this cruise. So far, I have gone on 16 separate dives to help complete surveys, collect samples, and assist my colleagues with instrument deployment.
By now, we have gotten into a general diving routine (although this can daily depending on other needs, boat availability etc . . .) so I thought I would share a play-by-play about my roles and tasks underwater.
We typically leave the Alucia around 7:30-8 am with our prepared dive gear, sampling equipment (many coolers filled with different bottles for water sampling, mesh catch bags for holding samples that we collect underwater, and a Niskin bottle), additional cylinders for a second dive, divers, and a few crew members.
We arrive at the reef site and Amy or Maickel will jump into the water to inspect the reef location. If they deem it suitable, the boat is either attached to a mooring or anchored and all the divers get ready to dive! This involves fastening clip-boards, dive slates, transect tapes, cameras, and mesh bags to our BCs (the vest-like things that we wear that we can inflate or deflate underwater to change our buoyancy), making sure our air is “on”, de-fogging our masks (to keep them from fogging up underwater), finding our fins, and making sure we have our weight belts/integrated weights on. We jump into the water in buddy groups (Amy is usually my buddy) and descend close the mooring/anchor so we can orient ourselves to wear the boat is in relation to the reef that we are diving on (this is important to do, especially on days when the water is more turbid and when it is harder to see).
Amy and I each decide on a general location to begin laying out our transects so we can begin collecting benthic coverage data. I hook one end of the transect tape around a piece of rubble (dead reef) and then I swim the transect tape 10 m across the top of the reef. When I get to the end of the tape, I hover over the line and estimate the coverage (using cm) of each substrate type (either living or non-living; coral, sponge, sand, rock, algae) that intersects with the transect tape. I do this for each meter along the line and when I finish, I reel in the line, swim over to another reef area, and complete the survey again. It usually takes me 30 minutes to complete 5 transects. Amy completes 5 transects as well.
After we complete these transects, Amy and I scope out coral colonies to sample. Amy uses a hammer and a chisel to separate off little pieces of different colonies and I hover beside her, record the samples that she is collecting, and hand her collection bags. We usually spend 15-20 minutes collecting these samples and by that time, it is time for us to complete the dive.
Our second dive of the day is almost identical, but with one sample collection addition – I collect reef-depth water with a Niskin bottle and I use this sample to understand the chemical composition of reef-depth water.
Thanks for reading!