Abstract
On the U.S. West Coast, deep-sea coral and sponge (DSCS) communities occur generally in waters deeper than 50 m. All corals in this temperate, cold-water region are azooxanthellate heterotrophs that feed only on the animals and organic material that they can catch with their tentacles, unlike the shallow, reef-building corals found in warmer regions. DSCS communities increase biogenic structure, providing shelter and nursery habitat, and increasing biodiversity and prey availability (Freese and Wing, 2003; Bright, 2007; Baillon et al., 2012; Henderson et al., 2020). Threats to these long-lived, fragile organisms from bottom contact fishing gear, potential offshore renewable energy development, and ocean warming and acidification have increased the need for DSCS research along the U.S. West Coast (Gómez et al., 2018; Salgado et al., 2018; Yoklavich, et al., 2018; Gugliotti et al., 2019). To date, studies have varied from species distribution and abundance (Yoklavich and Love, 2005; Tissot et al., 2006) to developing and validating predictive distribution models (Huff et al., 2013; Rooper et al., 2017; Kreidler, 2020) to finding medicinal uses for corals and sponges (Essack et al., 2011; Shrestha et al., 2018). Due to the vast area of unexplored seafloor within the U.S. exclusive economic zone (200 nautical miles off the coast) and the technological requirements of deep-sea research, there is still much to learn about the distribution and biology of DSCS. This information is critical to resource managers for effective conservation and management of DSCS habitats. The Magnuson-Stevens Fishery Conservation and Management Act and the National Marine Sanctuaries Act (NMSA) provide legal authorities to protect DSCS and/or their habitats. In 2006, the National Marine Fisheries Service (NMFS) and the Pacific Fishery Management Council (PFMC) designated 51 distinct seafloor areas as essential fish habitat conservation areas (EFHCA) to protect seafloor habitats from damage by either bottom trawls or all bottom contact fishing gears. In January 2020, NMFS and the PFMC implemented Amendment 28 to the Groundfish Fishery Management Plan (GFMP; Pacific Fishery Management Council, 2019), which modified EFHCAs by closing new areas identified as vulnerable and reopening areas deemed not vulnerable. The NMSA prohibits bottom disturbance from certain activities within areas designated as national marine sanctuaries, such as oil and gas exploration or extraction, cable laying, and other forms of seabed alteration or construction that disturb benthic communities.
NOAA’s Deep-Sea Coral Research Technology Program (DSCRTP) began a 4-year funding initiative for the U.S. West Coast in 2018. The goals of the West Coast Deep-Sea Coral Initiative were to: 1) gather baseline information on DSCS in areas subject to fishing regulation changes prior to the implementation of Amendment 28; 2) improve our understanding of known DSCS bycatch “hot spots”; and 3) explore and assess DSCS resources within NOAA National Marine Sanctuaries with emphasis on areas of sanctuary resource protection and management concerns. Following the 2018 research expedition supported by NOAA Ship Bell M. Shimada (Laidig et al., 2021), a second research cruise was planned for 2019 to further survey seafloor communities in priority areas off the West Coast from Washington to California. The 2019 expedition spanned 35 days (4 Oct – 7 Nov) and was conducted from the NOAA Ship Reuben Lasker (hereafter referred to as “the ship”), beginning and ending in San Diego, CA. Surveys were conducted in deeper areas (generally 500-1200 m) in 2019 than in 2018 (limited to <650 m). These two expeditions provide data on seafloor communities and DSCS assemblages over a broad range of depths 50-1200 m.
The science team assembled for this cruise were members of the EXpanding Pacific Research and Exploration of Submerged Systems (EXPRESS) campaign, a consortium of researchers from federal and nonfederal institutions that collaborate on scientific expeditions focused on deep seafloor habitats off California, Oregon, and Washington. EXPRESS supports researchers by leveraging funding, resources, personnel, and expertise to accomplish more science than would be possible by a single entity alone. The 2019 coastwide expedition included research partners from NMFS Southwest Fisheries Science Center (SWFSC) and Northwest Fisheries Science Center (NWFSC), National Ocean Service (Channel Islands, Cordell Bank, Greater Farallones, and Monterey Bay National Marine Sanctuaries), Bureau of Ocean Energy Management (BOEM), U.S. Geological Survey (USGS), and Monterey Bay Aquarium Research Institute (MBARI).
In 2019, we conducted several scientific outreach programs during the cruise. Over the course of the expedition, two live broadcasts, one port event, and continuous telepresence during Remotely Operated Vehicle (ROV) dive operations were hosted to engage and educate the public on the cruise mission and DSCS research. Live broadcasts were made to four classes at Pierpont Elementary School in Ventura, CA, and to a general public audience at the Exploratorium in San Francisco, CA. In port in San Francisco, a behind the scenes tour aboard the NOAA Ship Reuben Lasker and the Exploratorium were hosted, where visitors learned about the cruise objectives, survey tools, sampling methods, and telepresence capabilities used to conduct scientific research during the cruise.
Research objectives for this cruise were to:
- Collect DSCS baseline information at seven of the EFHCA sites and two groundfish trawl rockfish conservation areas undergoing protection modifications by the Pacific Fishery Management Council.
- Document temporal changes in DSCS assemblages at previously surveyed sites.
- Provide data to validate BOEM-supported cross-shelf habitat suitability models.
- Collect samples for identifying and understanding west coast DSCS and expand use of new technologies (ROV, Autonomous Underwater Vehicle (AUV), environmental DNA [eDNA]).
- Collect water samples for coastwide eDNA and water chemistry studies.
- Characterize DSCS and fish assemblages in unexplored areas of National Marine Sanctuaries.
- Collect DSCS and fish baseline information at potential offshore wind development sites.