Deep-Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND)

In January 2015, Dr. Tracey Sutton at Nova Southeastern University, Department of Marine and Environmental Sciences, was awarded an RFP-IV grant to lead the GoMRI project entitled 'Deep-Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND)'. This grant was extended through June 2020 and the total award amount for the 5-year project was $9,775,900.DEEPEND consisted of 17 collaborative institutions and approximately 105 participants (including students). DEEPEND planned to investigate deep-pelagic communities on short-term (sub-generational) and long-term (evolutionary) timescales to appraise extant recovery and potential future recovery of these communities using a suite of integrated approaches. These approaches included: 1) a direct assessment of Gulf of Mexico (GoM, hereafter) deep-pelagic community structure, with simultaneous investigation of the physical and biological (including microbial) drivers of this structure, in order to document biodiversity and 'natural' variability; 2) a time-series, 'hindcast,' comparison of biophysical data from 2015-2017 (DEEPEND sampling) to 2010-2011 (NRDA sampling) data; 3) an examination of differences in genetic diversity among key species; and 4) an assessment of the extant and potential future consequences of the DWHOS on the shallow and deep-pelagic biota. The DEEPEND Consortium conducted a 5-year sampling and analysis program that built on the synergy developed during an intensive NOAA-supported program (Offshore Nekton Sampling and Analysis Program; ONSAP; 2010-2011) in support of the Deepwater Horizon Natural Resource Damage Assessment (NRDA). ONSAP was run by DEEPEND PIs, including Sutton as ONSAP PI. DEEPEND had five major research objectives: Define faunal composition, community structure, abundance, and distribution of deep water column fauna; Document biophysical drivers of ecosystem structure; Determine genetic diversity among representative pelagic taxa; Quantify consequences of the DWHOS on the GoM pelagic fauna; and Develop an integrated outreach program will disseminate DEEPEND consortium activities to scientific, educational, and public sectors. Outreach Highlights As of June 30, 2020, DEEPEND research team members have participated in more than 290 outreach related activities including: school presentations, invited talks, summer camps, social media engagement, and more. Here are a few of our key outreach products and activities: WhaleTimes, Inc.'s Creep into the DEEPEND virtual research mission program for K-5 students directly involved over 15,000 participants both during the school year and at special summer camps across the United States. This program taught students about the deep sea and about DEEPEND's research through curriculum booklets, videos, games, coloring pages, 'Sea-mails', trading cards, posters, postcards, and live online interviews with DEEPEND researchers. Six teaching modules (Adaptations, Marine Environments, Pollution, Marine Navigation, Biodiversity, and the Nature of Science) were created by Dr. Denise Kendall for grades 6-12 and are publically available on the DEEPEND website. DEEPEND's Imaging Project completed by Dr. Danté Fenolio, who photographed thousands of deep-sea specimens while at sea for use across all of DEEPEND's scientific, education, and outreach products. For example, in addition to appearing in over a hundred media events and scientific publications, DEEPEND images have appeared as cover photos for the journals Science, Proceedings of the Royal Society, Deep-Sea Research, and as a dedicated feature page in the popular magazine Sport Fishing. Teacher workshops for grades 6-12 were held in Galveston, TX, St. Petersburg, FL and Dania Beach, FL. Teachers were provided with lesson plans on the marine environment (including the deep sea) and took part in the lessons and activities provided. Participants in the workshop had the opportunity to apply for the teacher-at-sea position on each DEEPEND research cruise. Research Highlights As of June 30, 2020, this project's research resulted in 44 peer-reviewed publications, 2 Books, 2 Book Chapters, 196 scientific presentations, and 89 datasets being submitted to the GoMRI Information and Data Cooperative (GRIIDC), which are/will be made available to the public. The project also engaged eight PhD students, 29 Masters students, and six postdocs over its award period. Significant outcomes of our project's research are highlighted below. Nearly ten years after the Deepwater Horizon disaster, extensive surveys reveal that deep-pelagic fish, krill, shrimp, and squid populations have crashed (declined by as much as 92%), with no evidence of recovery, in the offshore Gulf of Mexico. Of the possible explanations we have considered, the most likely is that this decrease is a prolonged impact of the Deepwater Horizon disaster. This finding has been documented in a manuscript that is in review in a high-level journal as of 30 June, 2020. Petrochemical contaminants (polycyclic aromatic hydrocarbons, PAHs) have persisted in the pelagic Gulf ecosystem much longer than expected (through late 2017, as late as has been analyzed). Deep-pelagic fishes, shrimps, squids, and gelatinous zooplankton have carried PAH levels in their eggs/gonads that are above sublethal levels, with likely population-level effects. Numerous lines of research have revealed an extremely high degree of vertical connectivity in the open ocean Gulf. Larvae of deep-living forms use the surface ocean as nursery habitat, diel vertical migrations are the rule for animals residing between 0-1200 m depth, and trophic markers of even the deepest-living taxa show surface production signatures. In summary, the open Gulf should be viewed as one large, integrated unit from the surface to great depths rather than a series of stacked ecosystems. Extensive field sampling and ensuing analysis, including genetic barcoding, has revealed that the Gulf of Mexico is one of the four most diverse deep-pelagic ecoregions in the World Ocean. DEEPEND taxonomists have identified nearly 900 species of fishes, 180 of which are new records, and many are potentially new species. For comparison, there are only ~1600 species of fishes known in the entire Gulf, including coastal and estuarine species. In summary, the Gulf fish fauna as a whole is truly oceanic in nature. Defining pelagic 'habitat' has been a longstanding problem in oceanography. Using an integrated approach (in situ data, physical oceanographic modeling, and microbial 'tracers') we developed a method for characterizing pelagic habitat in the Gulf and published this method in Limnology and Oceanography Methods. The extensive DEEPEND genetic barcoding program (over 500 species of fishes, 80 species of shrimps, 30 species of squids) has resolved many outstanding issues in deep-sea taxonomy, including linking early life history stages with their adult counterparts. The synergy between traditional (morphological) taxonomists and genetic identification should be viewed as a way forward for taxonomy in general. That said, DEEPEND has clearly demonstrated that net sampling and specimen examination is still the backbone of marine metazoan biodiversity assessment. Genetic methods are fraught with problems, and unreliable without voucher specimens. Our initiative has uncovered an unacceptably high rate of error in genetic databases such as BOLD and GenBank. This is particularly important as eDNA analyses become more popular among ecologists. We are a long way from having reliable, 'genetic-only' analyses, and if not done with care, genetic methodology could do more harm than good as we seek to protect oceanic biodiversity. Other methods of pelagic faunal inventorying, such as acoustics and in situ observation, also return much lower species-level resolution than net sampling, and are much less quantitative. These alternate methods should complement physical sampling, but currently cannot be considered substitutes. One of the potentially longest-lasting contributions by DEEPEND was training of a new generation of deep-sea taxonomists by some of the world's leading experts in their fields. The growing 'Taxonomy Gap,' the loss of taxonomic expertise worldwide without replacement, has been recognized by the United Nations Convention on Biological Diversity as one of the primary threats to its goals of protecting global biodiversity. Given how few programs such as GoMRI have ever existed, and how difficult it can be to fund taxonomic capacity building, we are both proud and grateful for this opportunity to make a difference.