The 20-day expedition, conducted in partnership with the National Oceanic and Atmospheric Administration (NOAA) and the Bureau of Ocean Energy Management (BOEM), will provide critical information to inform proposed restoration and management activities in mesophotic and deep-sea habitats.

The expedition is a part of the Mesophotic and Deep Benthic Communities (MDBC) Habitat Assessment and Evaluation project, a collaborative effort between USGS, BOEM, NOAA, and various partners from academic and research institutions. The MDBC portfolio includes four long-term projects that aim to improve understanding of mesophotic and deep benthic communities, inform management and restoration, and ensure ecosystem resiliency.

Mesophotic benthic areas are habitats along the seafloor that receive some sunlight, and deep benthic areas are those that receive very little to no sunlight. These ecosystems are vast and complex, and are foundational to the Gulf of Mexico’s food webs. Many animals, such as corals, sponges, and fish, including commercially important species rely on both mesophotic and deep-sea habitats.

Despite their depth, mesophotic and deep benthic ecosystems are threatened by natural disturbances and human activities, including climate change, ocean acidification, oil and gas related activities and commercial fishing. The 2010 Deepwater Horizon oil spill is estimated to have injured more than 770 square miles of deep-sea habitat and 4 square miles of mesophotic habitat. This included an estimated 263 km² of soft-sediment communities.

Restoration goals for mesophotic and deep benthic communities include assessing baseline conditions and restoring invertebrate and fish abundance and biomass for species injured by the oil spill, with focus on high-density coral and hard-bottom sites and their surroundings. However, there is limited information about these communities, which makes restoration efforts challenging.

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Aboard the University of Southern Mississippi’s research vessel Point Sur, an interdisciplinary team of scientists will assess, characterize, and map deepwater habitats to develop a better understanding of what healthy mesophotic and deep benthic communities look like and how they’re connected across the Gulf of Mexico.

Using a multicorer, a device that can collect multiple cylindrical tubes of sediment from the sea floor, and water sampling equipment, the team will investigate deep benthic communities at several sites that were previously sampled during the initial Deepwater Horizon response efforts.

They will also rely on a sub-bottom profiler, which is a type of sonar system that uses sound to map beneath the sea floor. This information will provide critical information about the marine geological context within and around the targeted benthic communities.

The data and samples collected from the Point Sur expedition will expand our knowledge of mesophotic and deep-sea habitats, particularly in those areas impacted by the Deepwater Horizon oil spill and inform the management and restoration of biological and georgical resources in mesophotic and deep benthic ecosystems.