- Deep Sea Fauna
- Environmental Variability
- Consequences of DWHOS
- Student Research
- DEEPEND Publications
We are in the home stretch for this DEEPEND cruise with only one trawl left to process on our last day out here at sea. This cruise has been just as productive as every other trip we have conducted with lots of hard work, long hours, and rewarding finds! Here are some fun facts from our six cruises out here in the Gulf of Mexico:
We have found great diversity of species for the major taxa: 61 cephalopod species, 120 crustacean species and 627 fish species! These are important numbers as in the past the midwater habitat was not considered a particularly diverse region.
Here are the winners for the most abundant animal in each category:
Most abundant fish: Cyclothone sp.
Most abundant crustacean: Euphausiids
Most abundant cephalopod: Pterygioteuthis sp. (P. gemmata and P.giardi)
With regards to operations, here’s what we know:
Number of miles traveled: ~6496 miles on the R/V Point Sur out here in the big blue!
Total number of MOC trawls successfully deployed and retrieved: 122
Total number of hours the MOC was in the water: 671 hours
We have 1764 hours of acoustics data collected.
We have ~40,000 species and team photos from Dante Fenolio’s efforts.
Photo: Acoustics attached to the MOC for deployment
What have we found so far? We have found five cephalopod species and more than 20 species of fish that are new to science (descriptions are in the works) and we have approximately 180 fish species that are new records for the Gulf. We have found that each time out here, we have been surprised about how changeable the water conditions have been as we go down the water column- from moving across eddy features to observing and documenting the outward flow of the Mississippi River. We have found that hard work is exhausting but absolutely rewarding as we have so much science to share with all that we have found so far! We have been able to support more than 30 students, research technicians, and post docs through the DEEPEND program to date. This has been essential to maintaining our productivity for the last four years.
So, how has all of this amazing science been possible? We give a HUGE thank you to NOAA/NRDA and GoMRI for this opportunity to explore this unknown region of the Gulf. We now have eight years of continuous data in the same region, using the same methods which allows us to explore connections, gaps, and patterns that occur within and between these depth layers.
We also thank Captain Nic and the crew of the R/V Point Sur for their tireless work to keep our science moving each and every cruise. We wouldn’t have any science to share without you guys along the way! Thank you!
Each DEEPEND team member wants to thank their home institutions for their support for this effort over the last four years. These cruises have an extremely surprising and enlightening endeavor and we have lots more science to report on from these efforts. We expect to have research output and publications continuing for at least the next ten years. Where would we be without Matt Johnston, our data manger and land connection while on our cruises? Thanks to him for all his efforts! April Cook, our rockstar project manager has kept us all in line for the last four years and continues to do so, thank you! And, we can’t go without thanking our amazing director, Tracey Sutton- his work ethic combined with humor has allowed us all to grow as a team over the years, thanks, Tracey!!
Photos: April and Tracey sorting a sample; Tracey with a Mahi
Keep checking in on us for more news, publications, and highlights from the DEEPEND science team as we continue to “fish for answers”…. Until we sail again!
My name is Nina Pruzinsky. I am a graduate research assistant in Dr. Tracey Sutton’s Oceanic Ecology Lab at Nova Southeastern University. I defended my master’s thesis on the “Identification and spatiotemporal dynamics of tuna (Family: Scombridae; Tribe: Thunnini) early life stages in the oceanic Gulf of Mexico” in May and will continue working in Dr. Sutton’s lab post-graduation. In my thesis, I determined characteristics that differentiate juvenile tuna species, which have been previously poorly described, and then mapped the distributions of the most abundant species (little tunny, blackfin tuna, frigate tuna, and skipjack tuna) collected in the Gulf of Mexico from 2010-2011 and 2015-2017.
Photo: Nina with a juvenile little tunny
With that being said, this is my first DEEPEND cruise! I am ecstatic to be a part of the team that is out surveying the Gulf’s deep pelagic ecosystem. I have worked with these specimens in the lab for the past two and a half years, and it is incredible to see the specimens when they first come up in the nets! The different coloration patterns and photophores of these deep-sea fish are amazing to see! On this DEEPEND cruise, I am working as the database manager and work alongside Natalie Slayden. Our job is to back process the fish specimens identified by taxonomists Drs. Tracey Sutton and Jon Moore. Check out Natalie’s blog below to learn more about our jobs at sea.
In regards to my research, I am continuing to sample the larval and juvenile tuna in the Gulf of Mexico. Scombrid counts on this cruise exceed all other DEEPEND cruises thus far! On this cruise, we have collected various scombrid species and life stages. The majority of our catch has consisted of larval and juvenile little tunny. Due to the collaboration with C-Image III, we have also fished/caught adult tunas as well. As Heather mentioned, we are collected tissue samples of these adults for C-Image III and for stable isotope analyses conducted by Travis Richards.
Photo: Mixed larval tuna species (mostly little tunny)
We have collected larval and juvenile frigate and bullet tuna. At the juvenile stage, these two species cannot be differentiated; thus, we are running genetic analyses to determine which species this specimen is (see picture below). Additionally, we found a skipjack tuna in the stomach of one of the adult little tunny that Max Weber caught on the cruise! The MOCNESS also collected a larval skipjack as well. We also caught an adult bonito, and Gray Lawson, our MOCNESS operator, caught an adult yellowfin tuna. It is exciting to see the diversity of tuna species collected this trip!
Photos: Max and Nina with a little tunny; Bottom photo: Gray with a yellowfin tuna
As I spent the majority of my thesis surveying larval and juvenile tunas, this cruise was the first time I saw adult tunas. We had several schools circling the boat, which was very exciting!! Hoping for more tuna sightings and catches as the cruise continues! J
The DEEPEND program has provided the opportunities for collaboration in so many areas over the last four years! In the education and outreach arena, we have been working with the Oregon Coast Aquarium (http://aquarium.org/education/oceanscape-network/) who highlights DEEPEND work and created our DEEPEND Vertical Distribution poster. This collaboration was made possible by one of our EO team members, Ruth Musgrave, who oversees our K-6 education components. We have worked with middle and high school teachers from Florida to Texas through our Teacher-At-Sea program and have remained in contact with many of them years after their at-sea experiences. We have also collaborated through community efforts such as the St. Petersburg Science Festival where both DEEEPEND and C-Image consortia shared space to enlighten children and adults about our offshore projects through interactive games and question and answer sessions.
Photos: DEEPEND Vertical Migration Poster and 2) C-IMAGE II and DEEPEND teams at the St. Petersburg Science Festival
Throughout the four years, our research efforts have also expanded outside of our consortium and other GoMRI groups. For example, in my case, I have been collaborating with other cephalopod researchers around the world about things we are discovering here in the GoM. From new species descriptions to future publications, I have truly benefitted from the DEEPEND work we have conducted to date!
One exciting new collaboration is the alignment of DEEPEND and C-Image III (http://www.marine.usf.edu/c-image/) consortia to tackle an existing gap in the offshore datasets we’ve been collecting. If you look to the DEEPEND shiptracker on our website, you will see the stations we are visiting for our MOC10 sampling work. What is great is that on August 10th, the C-IMAGE III team will head out to the same stations we’ve visited to conduct their longlining project. A total of 36 pelagic longline sets will be made with two gear sets per station (one during daylight and a second at night). This add-on longline survey will evaluate the abundance, food habits, and population demography of the predators, to take tissue samples for toxicology studies, and to evaluate the stomach fullness, species composition and to obtain genetic samples of prey items.
Photo: C_IMAGE III Director, Steve Murwawski catching a Red Snapper on a previous C-IMAGE cruise
Basically, C-IMAGE III will be collecting stomachs for a subsest of our consortia teams to examine to attempt to fill the gap of knowledge between our deep-sea organisms and their large pelagic fishes. What is the gap? Food web connections are difficult as there are many, many variables involved with who eats whom, when does everybody eat, at what depth are they eating, etc. If we can connect the DEEPEND organisms with these more shallow top predators, we will gain a better sense of the energy transfer that occurs between these two groups. We will be working with this new project when everyone is back on land and in the labs!
Assessing marine ecosystems health requires multiple tools to study in an integrative way environmental pollution and impacts across different biological levels. One of the main challenges is to link physical, chemical and biological components in large-scale ecosystems when little information is available. For example, the Deepwater Horizon oil spill in 2010, contaminated the water column in the Gulf of Mexico from the epipelagic (0-200 m) to the mesopelagic (200 -1000) and bathypelagic (>1000 m) habitats; but assessment of the impact to the deep-pelagic GoM was hampered due to a lack of comprehensive data regarding diversity, abundance, distribution, and pollutants baseline-content of pelagic fauna. Several programs since the spill (e.g. DEEPEND Consortium) have improved our knowledge and understanding of the deep-pelagic ecosystem, the largest habitat in the Gulf of Mexico, and on Earth. However, information regarding the source, composition and inputs of chemical contaminants to deep pelagic fauna is still absent. Chemical contaminants can alter biological diversity and ecosystem functioning, therefore are key for linking long-term population dynamics and environmental stressors.
As part of the DEEPEND Consortium, my role is to establish a time series of chemical composition in deep-pelagic fauna (fishes, shrimps, cephalopods) collected after the Deepwater Horizon spill. For this study, the analysis of polycyclic aromatic hydrocarbons (PAHs) was chosen because: 1) these compounds are common in crude oil; 2) are persistent in the environment; 3) their composition can be used to broadly detect the source of contamination; and 4) can be toxic to fauna. PAHs are a large group of organic compounds organized in multiple aromatic rings typically found as complex mixtures. They are present in petroleum, coal, wood, and their combustion products. When present in high amounts, for example after an oil spill in the ocean, PAHs can cause lethal and sub-lethal effects on fauna like juvenile and adult fishes, potentially increasing mortality, skeletal malformations, genetic damage, immunotoxicity, etc.
Recently, with the collaboration of different programs, we were able to establish a decadal assessment of PAHs in mesopelagic fish tissues as indicators of environmental contamination in the deep-pelagic ecosystem. The results generated from this study indicate deep-pelagic fishes were exposed to elevated concentrations of PAHs after the Deepwater Horizon spill (2010-2011). In 2015-2016, PAH concentrations were close to the levels measured in 2007; but only for muscle tissues, because elevated concentrations were found in ovaries containing eggs. The high concentrations of PAHs found in 2010-2011 (muscle tissue), and 2015-2016 (eggs) are within the range of PAH concentrations found to cause lethal and sublethal effects on fishes. These results suggest a long-term sink for oil in deep pelagic organisms, potentially greater than shallower counterparts. Our findings demonstrate the importance of monitoring the persistence of organic contaminants in deep pelagic organisms. However, our study also indicates the need for more extensive ecosystem-based efforts of the deep-pelagic ocean (> 10 years) to better understand the long-term impacts across multiple levels of biological organization.
Here are some of the animals I am examining for PAH contamination:
1) Cyclothone obscura; 2) Onychoteuthis banksii,; 3) Histioteuthis corona
For DEEPEND, I am one of the taxonomists that identify the cephalopods (squid and octopus) that are collected from the MOCNESS nets. I am also collecting two other mollusc groups, pteropods (Sea Butterflies) and heteropods (Sea Elephants). Once animals are identified, tissue could go to one or more of the following places for further DEEPEND study: Stable isotope analysis (examples food web interactions among fauna), PAH (studying possible contaminants), or genetic barcoding for species identification verification and genetic diversity analysis.
Photo 1: A Sea Elephant, Carinaria sp.
Photo 2: A sample of Sea Butterflies (pteropods)
One of the advantages of using the MOCNESS is that we can collect organisms at discreet depths to analyze patterns on a fine scale. All focus animals: fishes, crustaceans, gelatinous organisms, and cephalopods are examined to piece together a more complete picture of the midwater column dynamics as they all contribute to the carbon moving from the surface waters to the deep-sea floor.
Team Mollusca are looking at vertical migration patterns for our three groups. Past studies on cephalopod vertical migration involve very few individuals per species so it is important to make the most of the large collection we have to further analyze these patterns. Our findings suggest that there is no one set vertical migration pattern by group but the patterns differ by species. For example, deep-sea pelagic octopods and the Vampire Squid are not found above 600m in the water column while the Moon Squid and Firefly squid move from the mesopelagic (200-1000m) to the epipelagic (0-200m) nightly, presumably for feeding purposes. We are noticing similar patterns in the heteropods, some migrate upwards and some do not. Pteropod analysis is underway at this time, stay tuned!
Here are some of the molluscs that are migrators and non-migrators,
Non-migrators: Japetella diaphana and Vampyroteuthis infernalis
Migrators: Selenoteuthis scintallins and Pterygioteuthis sp.