Gray's Reef National Marine Sanctuary
Gray's Reef National Marine Sanctuary
Gray's Reef Expedition 2012
Mission Information
 

Wednesday: June 7, 2012
Log Summary

Greg McFall
Gray's Reef
Chief Scientist

Working out in the ocean is always an adventure . . .
Sometimes the seas are your friend, and sometimes they aren't. During the second leg of the Gray's Reef National Marine Sanctuary cruise aboard the NOAA Ship Nancy Foster, the seas were not very friendly! Tropical Storm Beryl kept us at the dock a few extra days, and then once we were finally able to get offshore, we found that the storm had made underwater visibility almost unworkable (well, it was unworkable for a day, then it cleared up to barely workable).

Dr. Roldan Munoz attempts to survey cryptic fish during poor visibility in Gray's Reef

Dr. Roldan Munoz attempts to survey cryptic fish during poor visibility in Gray's Reef National Marine Sanctuary
(Photo: Randy Rudd)

With time, visibility improved, but the seas kept picking up with the passage of small storms. On numerous days we were forced to stay on the ship instead of deploying divers using the small boats, due to storm activity in the area. Thankfully we were able to use this time to conduct mapping operations and Dr. Laura Kracker was able to survey using the ship's fisheries sonar. So while we were not always able to collect the data we'd planned, we were able to collect data! And while poor visibility limited what the invertebrate and fish surveyors could accomplish, the fish telemetry team was still able to service the acoustic array deployed within the sanctuary (these tasks had been planned for Leg I, but were not completed because that cruise was cut short by Tropical Storm Alberto). Another significant accomplishment of this trip was the first use of closed-circuit rebreathers by NOAA Divers aboard a NOAA platform.

Most divers are familiar with traditional "open-circuit" SCUBA where a diver inhales a breath and then exhausts it to the surrounding water. With a closed-circuit rebreather (CCR), the diver inhales a breath and when they exhale, the breath passes into a "scrubber" material which removes the carbon dioxide and recycles the remaining oxygen. In this manner, the diver "re-breathes" the good oxygen which makes up the majority of what we exhale. Because none of the oxygen is "wasted", divers can stay down much longer than they would be able to with open-circuit scuba. Additionally, because there are no bubbles to exhaust, divers can get much closer to the marine life they are studying as there are no noisy bubbles scaring them away. NOAA has been looking to utilize this technology for several years and we were very fortunate to have such a supportive crew for these first NOAA operational dives using this advanced technology.

Chief Scientist Greg McFall prepares for a dive using his closed-circuit rebreather

Chief Scientist Greg McFall prepares for a dive using his closed-circuit rebreather.
(Photo: "Nemo" McKay)

As always, a research cruise is not possible without the tremendous support of a whole team of people. In this case, not only did we depend upon their time and expertise but we also used a whole lot of their patience, flexibility and good humor, in dealing with all the weather delays and challenges with conditions!

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