A peek out the port this morning revealed the best visibility in the water that we have had so far during the mission – over 50’! It is wonderful to see that far – the reef jumps out though the habitat ports, and from the water, the habitat can be seen in its entirety. The watery blue is so rich and complete – what an amazing sight. Aquarius was made for mornings like this!
We had an incredibly productive science day today. Jim and I repositioned some of the flow probes over different barrel sponges to measure the rate that they can pump water. Tomorrow, Jim will collect water samples from the same sponges to be analyzed for different components to see how much material they are removing from the water with their efficient filtering mechanisms and how much they are releasing in terms of certain nutrients.
n addition, the four of us spent most of today working on our control volume sampling apparatus. We successfully collected six sets of samples – totaling about 60 samples in all – to be analyzed for chlorophyll and nutrient concentrations. As mentioned earlier, this will allow us to see how much ‘stuff’ the reef is removing from the water column. This is a relatively labor intensive process and requires significant help from and coordination with our amazing surface support team (without whom, this project would be impossible!). Our two aquanaut dive teams spent over well over twelve hours total in the water today – mostly around 70’ deep. This would be impossible to do if diving from the surface (without significant decompression each day). Everyday, we realize more and more how valuable the Aquarius platform is for accomplishing science out on the reef. Studies like ours simply could not be done here otherwise.
Long amounts of time out in the water give us the chance to observe and reflect on phenomena around us. One observation that we have all made is the amount of scour and sediment movement that occurred from the waves generated about a week ago by hurricane Dennis. In the shallow waters (around 50’ deep), most of the former sand patches have been eroded to a hard, old coral reef pavement. Some of this pavement probably has not been exposed in many years. As you get deeper in amongst the spur and groove of the lower reef, we still see significant scour (at around 65’) in the deeper sand channels. However, starting around 70’ deep, sand waves appear in the sand channels that, though relatively small, are still about 10-15 cm high. In these areas, there are alternating bands of exposed old reef and buried new reef. Some corals and soft corals that were healthy only a week ago are now buried under the sand, and new, barren substrate is exposed opening space for the colonization of other organisms. This is a very natural process that transports sediment from the shallow to the deep reef, but large storms tend to accelerate what is generally observed to be a reasonably slow process. It is fascinating to observe these dramatic effects, and our curious minds have already been mulling potential projects to explore the details of such events.
At the end of the day, we are exhausted, yet happy knowing that we accomplished so much. We are beginning to realize that our time under the sea is drawing to a close (only one full working day left!!!), but, for now, we must focus on the science that we need to accomplish and enjoying the watery world around us.
Today was officially “collect the data” day. After a few days of setting up the instruments, troubleshooting, testing the water sampling lines and getting our system in order, we were ready for a full day of sampling from morning ’til night. Jim and Greg headed out bright and early to check on the sponge experiments and then headed over to the “control volume” sampling array. Kristen and I stayed in Aquarius and had a nice time visiting with some Girl Scouts who stopped by (including one from the coolest state in the country- my home state of Pennsylvania). After a few test runs by Jim and Greg, Kristen and I gave them the tag team and took over sampling during the afternoon. All in all, it was very successful and we were able to get through a couple of very smooth, clean sampling routines.
The surface support crew did a spectacular job once again, and always seemed to be diving down the lines to grab our samples just as we were finishing the experiment. As the day wore on, we all started to feel the cold a little bit, hanging out at 70 ft. Jim had the smart idea to hover around 60 ft where the water was noticeably warmer, so we each took turns running samples, taking pictures, or watching the action from above. I got some great shots of this big old lobster that was sitting behind us under some rocks. He seemed fat, happy, and content watching these funny looking humans wandering around the reef.
Kristen and I stayed out until 5:30 pm while Greg and Jim maintained the station for one last set of samples to be collected. Around 7:30 pm our last set of samples were done and the surface crew headed in for the night.
Hopefully tonight I’ll make it out for my first “hooka” run to do night photography. I’m pretty excited about it and crossing my fingers the nurse sharks will still be there. With so much time in the water, I think I’m starting to grow my own fins. Not that I’ll need them, the fish don’t seem to care one way or the other if I’m there.
The habitat is starting to feel like home now. Ross and Otter, our habitat technicians are really treating us right, with lots of good snacks and warm Tang on our stops back at the wet-porch for air fills.
Our time here so far has been very productive! We have been spending most of our time during the first days getting the equipment ready for the control volume experiments.
One of the coolest things about spending so much time in the water is that you see things that you wouldn’t normally have time to notice: fish making mistakes and bumping into things, big fish eating littler fish, some really aggressive little fish who push the big fish (and us!) around. Last night we were treated to several Caribbean reef squid displaying outside the dining port hole.
Things are going smoothly, the scientists are getting lots of good work done so they are happy although also tired after a long day in the water. Everyone sleeps well down here….it’s quite a view to fall asleep to. Scheduled around today’s regular work was a visit and quick meeting with Amatzia Genin, a collaborating scientist from the Hebrew University in Israel, along with some other members of the topside science team. But it was a quick “power meeting” because they were diving from the surface and were not saturated like those of us that are living down here, so their time was very limited. That is the beauty of saturation diving. From saturation we are able to do in a matter of days what it would take weeks or even months to do if you were diving from the surface. This is precisely what makes Aquarius such and invaluable tool for scientist working in the sea.
Well, the time has come for me to stage out on hookah and get some work done outside. It gets pretty busy down here as we always try to maximize our time in the water taking care of business, looking out for our science team and claiming back our habitat from the constant growth of marine life.
Things are going very well down here. We are collecting real time data and have gotten the bugs worked out of the science sampling gear out on the reef. We haven’t seen the surface in several days, but we can tell it’s a little bouncy up there by the feel of pressure changes on our ears. When the larger swells go over the top of us we feel something similar to what one feels when you fly in an airplane. The visibility outside is clearing up a little more each day as the water settles out from the previous stormy weather.
I spent around four hours out on hookah today cleaning and working on the outside of the Habitat. It’s a constant battle when you put something on the sea floor and the ocean begins to claim it for its own. Valves and piping must be cleaned regularly and working from saturation allows us to get long dives in and give the habitat the attention she needs and deserves. Today while working, I dropped a tool and when I looked down, I saw fish of all sizes a dart around it. As I dropped down to retrieve it I saw what all the excitement was about……a large ball of bait fish or “silver sides” was swarming underneath the habitat. Every one was trying to get in on the action, several large Nurse Sharks and a big Atlantic Stingray were in the thick of it all, with about a dozen Black Grouper racing through the fray gulping up mouthfuls of fish. All of the action had the smaller Snapper and Yellowtail all worked up as well zipping about in every direction. When I first saw the bait ball it was about 12 to 15 feet across, but after about 2 hours it was reduced to a small scattering of little fish, the Nurse Sharks lounging on bottom, fat and happy after their very large meal.
The ocean is full of amazing sights, it’s never a dull moment down here.