10 years after the Deepwater Horizon oil spill
Today (April 20, 2020) marks the 10th year since the Deepwater Horizon oil spill occurred in the Gulf of Mexico. Approximately 5 million barrels of hydrocarbons (oil) spilled into the Gulf for 87 days following the explosion, and since then, DEEPEND (along with several other consortia) have been researching the effects that the oil spill had on the Gulf’s entire ecosystem. Oil reached the seafloor, the open-ocean water column, coastal areas, continental shelf regions, and even was found in marshes and estuaries. “It was an entire Gulf of Mexico-wide event,” Dr. Tracey Sutton said in an interview with Oceana.
Often, people remember the oil that was visible at the surface; however, it’s important to know that 100% of the oil occurred within the water column and affected life throughout the entire ecosystem, especially in the poorly-studied deep pelagic environment ( > 200 m depth) where the Macondo wellhead broke (~1500 m depth).
“As far as we know, the actual impact of the spill is not over yet,” Dr. Tracey Sutton explained in Oceana’s interview.
In another interview with the Independent, Dr. Sutton stated, “In 2017, we were still finding oil contaminants in the eggs [of deep-sea organisms] above levels known to be sublethal for animals. We also saw an overall decline in animal numbers.”
With industry drilling deeper for resources, the risk of another spill occurring increases. Dr. Sutton told the Independent, “another deepwater spill is still very much a real possibility.”
Photo by: U.S. Coast Guard—Reuters/Landov
Grad Student Slayden Knows Age is More Than a Number for Oil-Exposed Deep-Sea Fishes
“The ocean’s deep-pelagic ecosystem is the largest and least understood habitat on Earth. In the Gulf of Mexico, it was the largest ecosystem affected by the Deepwater Horizon incident. Because there was very limited pre-spill data about deep-pelagic organisms’ biodiversity, abundance, and distribution, it is difficult to determine how oiling may have affected different deep-sea species.
Information about the longevity and age at reproduction of key Gulf of Mexico deep-sea fauna, such as lanternfish or fangtooths, is crucial to determine their vulnerability and resilience to disturbances such as oil spills. However, the depths at which these organisms live and the challenges involved with raising them in captivity or tagging them in the wild make collecting this data difficult.
Natalie Slayden uses ear stones, called otoliths, collected from fish living in Deepwater Horizon-affected waters to study the age and growth of nine Gulf of Mexico deep-sea fish species. Her research can be used to estimate the lifespan and age at which these deep-sea fishes reproduce to determine how quickly a potentially compromised assemblage might be replaced following an environmental disturbance.
Natalie is a master’s student with Nova Southeastern University’s Department of Marine and Environmental Sciences and a GoMRI Scholar with the Deep-Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND) Consortium. The GoMRI community embraces bright and dedicated students like Natalie Slayden and their important contributions.
The GoMRI Scholars Program recognizes graduate students whose work focuses on GoMRI-funded projects and builds community for the next generation of ocean science professionals."
Congratulations Natalie from the entire DEEPEND team!!
DEEPEND at the Gulf of Mexico Oil Spill & Ecosystem Science Conference
DEEPEND will be heading to the Gulf of Mexico Oil Spill & Ecosystem Science Conference from February 3-6, 2020, in Tampa, FL. We will be represented by 18 talks and 6 posters. Our team will be presenting data on a wide range of topics, such as: faunal trends and baselines, drivers of pelagic ecosystems, indicators of petrogenic contamination, faunal inventories, open-ocean restoration, and education and outreach. We also have three PIs chairing sessions: Dr. Tracey Sutton (Session 2), Dr. Rosanna Milligan (Session 11), and Dr. Isabel Romero (Session 20). Come and learn more about our research! Check out our presentation list below. Hope to see you there!
Dr. Tracey Sutton Awarded the 2019 NSU Provost's Research and Scholarship Award
For the second time in NSU history, there were two Provost’s Research and Scholarship Award winners. Nova Southeastern University (NSU) Executive Vice President and Interim Provost Ron Chenail, Ph.D., presented Mariana Morris, Ph.D., and Tracey Sutton, Ph.D each with the 9th Annual Provost’s Research and Scholarship Award.
The purpose of the award is to recognize a faculty member who has demonstrated significant achievement in support of NSU's mission to foster scholarship, intellectual inquiry, and academic excellence. Research and scholarship are two of NSU's eight core values, and excellence in these areas enhances education, patient care, and public service, and develops superior scholarship.
Deepesh Tourani Thesis Defense - Inferred Function and Dynamics of Microbial Communities from Northern Gulf of Mexico
As part of the DEEPEND Consortium, our laboratory has been characterizing the microbial community composition and structure in the northern Gulf of Mexico (NGoM) pelagic waters using modern molecular ecology methods. We had previously sequenced a large cache of 16S rRNA gene data, which included 466 samples from two cruises in 2016 (May: DP03, August: DP04). To enhance taxonomic identifications, Mr. Tourani's MS thesis in Jose Lopez's laboratory at Nova Southeastern University has taken the same baseline 16S data and transformed it to infer the potential functions of the midwater microbiomes across time and space. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) approach was used for predicting biomolecular function based on the KEGG metabolic database. Strong depth stratification of metabolic function was observed (p<0.001), with a major shift in function between euphotic zone and aphotic zone, associated with a major differential abundance of photosynthetic functional signatures. Temporal analyses showed photosynthetic primary productivity was significantly different across season but not year, which may be attributed to high seasonal outflow of the Mississippi river.
Grad Student Pruzinsky Uses Morphological Patterns to ID Young Tuna for Population Assessments
"The Deepwater Horizon oil spill overlapped with the spawning activities of many ecologically and economically important tuna species. However, the significant knowledge gap regarding early life stage tuna taxonomy and distribution makes it difficult to understand how the spill may have affected them.
As a graduate student, Nina Pruzinsky examined the abundance, distribution, and morphological characteristics of larval and juvenile tunas (Scombridae) and identified primary drivers of their distribution to help fill this gap and inform future management and conservation efforts.
Nina, who recently completed her graduate studies, was a master’s student in Nova Southeastern University’s Department of Marine and Environmental Sciences and a GoMRI Scholar with the Deep-Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND) Consortium.
The GoMRI community embraces bright and dedicated students like Nina Pruzinsky and their important contributions. The GoMRI Scholars Program recognizes graduate students whose work focuses on GoMRI-funded projects and builds community for the next generation of ocean science professionals."
Her story can be found by clicking this link.
Congratulations Nina from the entire DEEPEND team!!
DEEPEND participates in a historic expedition: video of a live giant squid in the Gulf of Mexico!
Dr. Edie Widder did it again! With her colleague, Dr. Nathan Robinson, Edie used her MEDUSA camera platform to capture video of a live giant squid deep in the Gulf of Mexico during a recent NOAA Ocean Exploration and Research-supported cruise. This is the first recording of a live giant squid in the Gulf of Mexico (Atlantic Ocean, for that matter), and only the second such filming ever. Of course, the first was done by none other than… Dr. Widder, who also captured the first-ever footage of a live giant squid in the waters off Japan. The research cruise, entitled “Journey into Midnight: Life and Light Below the Twilight Zone,” was led by Dr. Sönke Johnsen of Duke University. Please read Sönke’s story here. Regarding DEEPEND, five of the twelve scientists onboard were DEEPENDers, including Co-PIs Tammy Frank, Heather Judkins, Heather Bracken-Grissom, Danté Fenolio, and DEEPEND Director/PI Tracey Sutton. Dr. Heather Judkins was first to identify the animal in the video as a giant squid, with this diagnosis later confirmed by DEEPEND Co-PI Dr. Michael Vecchione. Adding to the DEEPEND vibe was the fact that the cruise was conducted on the R/V Point Sur (University of Southern Mississippi, operated by LUMCON), on which all of the DEEPEND deep-trawling efforts have been based. Spectacular ship-time services, as always.
The giant squid story has been a global media sensation, featured by the NOAA Office of Exploration and Research; Discovery Channel; NY Times; Washington Post; USA Today; OCEANX; and CNN, among hundreds of others.
In addition to MEDUSA deployments, the Journey into Midnight science team had a number of other exploratory operations, including midwater trawling below 1000 m depth, ROV video transects with specimen collection, and shipboard measurements of the vision, bioluminescence, and reflectivity (color) of animals inhabiting the bathypelagic realm, earth’s largest and least-explored habitat. With respect to trawling, Dr. Sutton collected specimens for 14 ongoing projects, demonstrating the importance of sampling in addition to observation. Without such sampling, taxonomy (the science of knowing what species you are observing) would not be possible! We would instead be left wondering, “Oooh, that thing in the video looked so cool! What was it?” In total, 129 fish, 57 crustacean, and 13 squid species were collected, including many rare species, some of which we suspect are new records or new to science.
Among other scientific achievements of the cruise, Drs. Sutton and Fenolio were able to record the bioluminescence display of the Threadfin Dragonfish (Echiostoma barbatum) – something so fantastic it is hard to believe it is real. Owing to the skilled collection abilities of the ROV pilots, many specimens made it to the surface in near perfect condition, allowing for a range of high-resolution anatomical studies. With respect to vision in the midnight zone, a primary aim of the crustacean survey was to assess the ability of deep-sea shrimps to visually identify each other (i.e., conspecific recognition). Achieving this aim included measuring eye size to body length ratios across 15 species of shrimp, modeling the distances at which their bioluminescent signals remain detectable, and predicting the appearance of these signals in context of their visual acuity.
So, from all of the DEEPEND team, our deepest congratulations to Edie and Nathan! This was a testament to your hard work and ingenuity!