Posted by: Saul Rosser
By Doug Rasher
Today was a great day out on the reef. We rolled out of bed at first light, brewed up some coffee and ate our oatmeal, and began our day of data collection on the reef well before most people head out to work at their normal jobs on land. As we swam across the reef in the morning, we noticed the daily activity of the reef had already picked up by 8am. We passed a turtle grazing on a large sponge on our morning commute along our excursion line from the habitat to our work site, and we were welcomed at our work site by grouper, permit, snapper, barracuda, and nurse sharks looking for their breakfast. After checking in with the habitat on the intercom at the waystation (where we can also re-fill our SCUBA tanks!) we began our work. Today’s work entailed removing and dismantling some of our cages that have housed seaweed-eating fishes over the last 10 months, deploying cameras in these plots to observe grazing on the seaweeds that have been growing in these cages, and photographing corals inside other cages to track changes in coral growth over time. We spent 6 hours on the reef, so we were ready for a hardy dinner upon our return. However, the day was not over….
After dinner, we anxiously waited for dark to set in. We planned for a 2 hour night dive, and couldn’t wait to get out there. Our research goal for our night dive was to check inside each remaining cage in our experiment and count the number of nocturnal creatures residing in our cages. This is important because there is a complete shift in reef communities between day and night. Because it’s convenient to work during the day, we scientists pay most attention to the day-time reef community. But with the use of Aquarius, we can go out for long excursions at night and determine if nocturnal animals are having an impact on our study.
As we set out on the night dive, we were surrounded by the glow and deep hum of the habitat, but this soon faded away to darkness as we worked our way over the crest of the reef. We swam slowly down our excursion lines, only able to see as far as our torches would permit. With neutral buoyancy, it really felt like we were in outer space. After 2 hours, we completed checking on our cages – no nocturnal creatures to speak of, with the exception of the occasional brittlestar. Good for our experiment. At the waystation, we shut our torches down, and waved our arms around to see the bioluminescent plankton flicker in the water – pretty amazing. We radioed to the habitat that we would return home. As we approached the glow of the habitat in the surrounding darkness, it felt like our return to the mothership after an expedition on a foreign planet. This was interesting because it made me realize that despite our fascination with outerspace, there’s so much left to explore right here in our innerspace.