The image of a 2,500-pound aluminum cage being lowered off the deck of a research vessel into the Gulf of Mexico, headed for a seafloor almost three miles below, where it will sit alone and in total darkness for a full year, is subtly shocking. No human will examine it. Its sensors won’t be adjusted by a technician. It will merely observe and document changes in temperature, variations in oxygen levels, and the slow rhythms of a world that most people will never see and seldom consider.
This is a close-up view of NOAA’s deep-sea restoration research. Not a shiny aquarium tank or a glossy lab. A crew of scientists in safety gear watches from the Nancy Foster’s deck as a triangular metal frame, studded with orange marker buoys that resemble construction hard hats almost comically, disappears into dark water. The entire scene has a humble yet subtly exciting quality.
The project is a part of NOAA’s long-term, multi-year Mesophotic and Deep Benthic Communities restoration effort, which aims to restore the Gulf’s deep-sea habitats that were severely harmed by the 2010 Deepwater Horizon accident. Shorelines were not the only areas covered in oil from that spill. Coral communities that had been steadily and slowly expanding for centuries were smothered as it reached down into areas where light never reaches. It is not an easy task to restore them. The urgency of this research is partly due to the fact that it is still unclear whether complete restoration is even feasible.
The landers were designed by marine biologist Andrew Davies of the University of Rhode Island, who states bluntly, “We focus a lot on space exploration, but we know so little about what’s going on in the deep ocean.” When you take into account that the Gulf of Mexico, one of the Western Hemisphere’s most economically and ecologically significant bodies of water, still contains enormous expanses of seafloor that scientists have hardly documented, that observation takes a different turn. In actuality, these landers are completing gaps on a map.
The long-term data collection is what sets this particular effort apart. Prior studies have frequently relied on short ROV dives, which are costly windows into the deep. In order to continuously gather data on the environmental conditions surrounding deep coral communities, the new benthic landers can be left in place for months. Water chemistry, temperature, and oxygen levels. In the absence of this type of baseline data, which has never been available for these habitats, coral outplanting initiatives would essentially be speculative.
This lander work is accompanied by an equally ambitious modeling endeavor. Compared to global coral models that function at scales of tens of kilometers, NOAA’s team has been developing predictive habitat models at resolutions of only tens of meters. Through the use of statistical modeling techniques, ROV video surveys, and high-resolution seafloor mapping, the team is now able to forecast not only the potential locations of corals but also the likelihood of dense populations in particular areas. In priority areas spanning from Texas to Florida, thirteen coral taxa—from black corals to soft corals to stony corals—are being modeled.
Whether the models will function as well in untested Gulf regions as they do in the areas already surveyed and how long full restoration will take are still unknowns. However, there’s a feeling that the science is finally catching up to the scope of the issue as this work develops across several research fronts at once. Despite our reliance on and occasionally disastrous disruption of the Gulf’s deep waters, we have been largely unaware of them. These landers are starting to alter that as they sit silently on the ocean floor.
