|For more than a month, EPA’s Ocean Survey Vessel (OSV) Bold is studying the health of the waters around Puerto Rico and the U.S. Virgin Islands. EPA scientists and non-scientists will blog about their research and what it’s like to live and work at sea.|
About the author: About the author: Charles LoBue serves as the chief scientist and diver for the US Virgin Island leg of the OSV BOLD voyage. He is an environmental scientist in EPA Region 2 in New York City.
We’re at anchor in St. James Bay on the eastern corner of St. Thomas, giving us access to both St. Thomas and St. John stations. Our daily routine has already been well established, and with three dive teams making three dives each a day, filling scuba tanks is an essential task. The breathing gas that we use is Nitrox, which is air spiked with extra oxygen. Increasing the amount of oxygen decreases the nitrogen breathed in while diving, which in turn allows for longer dives without saturating our bodies with nitrogen levels that could cause decompression sickness or the “bends.” Nitrox is specially blended daily on board, with factory efficiency, by the BOLD technicians.
Planning for each day always starts the night before, when after dinner, the survey coordinators and BOLD captain meet to finalize dive plans that start the next morning. Dive team assignments are posted in the ship’s laboratory, which serves as a survey operations center. Divers are responsible for checking the oxygen content of the Nitrox in their tanks, and before retiring each night, they must analyze the air in his or her tanks assigned for the next day.
In the morning, divers check the assignment board to see which boat they’re in and the order of boat deployment. The teams stage their gear for loading onto the boats, with care to include all of the dive gear, survey and sampling equipment, drinking water, and oxygen kit. The gear is methodically loaded; missing one piece of equipment or gear would abort a survey and require a return trip to the BOLD. Once the boats are loaded, divers are on their way to start their work. GPS units are used to locate the station, and a snorkeler confirms that the site is appropriate to “count.” If it’s a go, two divers gear up and splash in to begin the survey; in about 10 minutes, two more divers descend to fill out the survey team. The observations are performed and recorded according to our protocol.
When the divers are finished, they return to the BOLD where samples are logged and refrigerated, data sheets are rinsed and dried, and dive gear is rinsed and hung to dry. Data is then entered into computer spreadsheets by the statisticians, with rigid review by the diver. Water samples are filter-processed for various analyses. Logged data for each diver is entered into the dive officer’s spreadsheet to track each diver’s activity and to ensure that no one has built up too much nitrogen in his or her system after several days of diving. After a long day of being the water, the whole process begins again for the next morning.