On June 24, the Baseline Explorer departed from Harbor Branch for a destination approximately seven miles offshore of Stuart, Florida. The science team was led by project PIs Joshua Voss and Shirley Pomponi (HBOI-FAU), and Voss lab students Michael and Jennifer. The Baseline Explorer’s target location was based on research conducted by Harbor Branch PI John Reed in the 1980s, where he documented Oculina reefs in 200-300ft of water off the East coast of Florida. Oculina varicosa is a slow growing, nonphotosynthetic coral that forms deep reefs, providing critical habitat for commercially important fish and invertebrate species. The Oculina reefs are found as far south as Jupiter, Florida and stretch all the way up to North Carolina. Reed’s research on these extremely long-lived and important reef builders has led to the creation of an Oculina Habitat Area of Particular Concern (HAPC), where bottom trawling is not allowed. Our target location for this cruise was just south of the HAPC boundaries; the limitation being that coordinates for the reefs were based in a much less accurate positioning system available in the 1980s. Our objectives were threefold: 1) to develop collaborative at-sea capabilities between Harbor Branch-FAU and Project Baseline, 2) to locate and document the Oculina reefs, and 3) to assess any damage to the reef, such as that caused by trawling.
The Baseline Explorer’s tech diving team, led by Dr. Todd Kincaid (Project Baseline, Global Underwater Explorers), dove first to scout the location, but found no signs of the reef. At the same time, however, the team did not see any obvious signs of trawling damage that would indicate a reef was once present and was now destroyed. On both June 25 and 26, Josh dove in one of the Baseline Explorer’s Triton submersibles rated to 300m with pilot Robert Carmichael (Project Baseline, Brownie’s Global Logistics). Although the Oculina fields reported decades before were once again not observed, they located a vast field of the black coral Stichopathes over a reef habitat likely comprised of ancient compressed Oculina skeletons. Throughout the dives, although they found evidence of human debris on the reef, the team also discovered that the reef is providing habitat for deepwater reef fish, sea bass, and snowy grouper. The tech divers were also able to collect samples of three black coral species and several sponges for morphometric and genetic analyses.
The use of manned submersibles rather than remotely operated vehicles (ROVs) has both advantages and disadvantages. Unlike ROVs, the manned submersible was not attached to the ship via a communications tether. This allows more freedom for movement and maneuverability with the sub, but also limits the communications capabilities between the sub and the surface. Specifically, the sub cannot transmit images or video in real time to the surface support team, as can be done with an ROV. They also experienced the strong currents of the Gulfstream, which made accurately hitting a target site and coordinating meet ups between the sub and tech team much more difficult.
Despite the challenges associated with research at sea, the collaborative effort between Harbor Branch Oceanographic at Florida Atlantic University and Project Baseline was a success and we look forward to future opportunities to combine the Baseline Explorer’s unique tools and capabilities with more research of deep reefs off the coast of Florida and beyond.
The cruise was covered by media teams from several parties, including FAU, Project Baseline, TCPalm (see below), CBS12, and WPTV5. Please click here for our full Flickr album and see the embedded video above for the highlights of the sub dives.