After the research cruise in which Celeste helped Nancy Rabalais and her team measure the largest Dead Zone yet, news agencies are taking notice. Yesterday I dove with Nancy and Ben Acker of LUMCON at a site in the heart of the Dead Zone, station C6C (featured in many previous posts). Nancy maintains multiple SONDEs on a leg of the oil platform to measure dissolved oxygen, temperature, salinity, and other important parameters. Our purpose yesterday was to search for a SONDE lost on a previous dive and introduce the CBS News team to the region of hypoxia. We also wound up providing footage for the CBS News crew to use in their segment that you can watch HERE. I shot the underwater footage. We’ll be posting the full video later. Here are some shots from the R/V Acadiana yesterday.
By Paige Jarreau. LSU biological sciences graduate student Mike Henson recently conducted field research in the great big blue! Mike works in Dr. Cameron Thrash’s lab. We asked him to tell us more about his field experience at sea below. Enjoy!
Waves stretch far into the horizon. The sun’s rays pierce the crystal clear blue water. The ocean here gives no hints about its oxygen-less waters beneath its depths. Yet, about 100 miles west of Manzanillo, Mexico in the Eastern Northern Tropical Pacific is one of largest anoxic bodies of water, or oxygen minimum zones (OMZ), in Earth’s oceans.
OMZs form when nutrient rich bottom waters from the Pacific Ocean are brought up to the surface, causing large blooms or growth explosions of photosynthetic algae. As the algae begin to die, other microscopic organisms (or backterioplankton) in the water consume oxygen to metabolize organic matter produced by the algal cells. Once you reach 100 meters below the surface, oxygen levels begin to decrease. At 300 meters, the oxygen has been completely consumed. Any organisms such as fish passing through these areas that are incapable of living without oxygen will die unless they can escape to the more oxygenated surface waters.
This may sound familiar to many Louisianans. However, unlike the hypoxia (a.k.a. the “dead zone”) that occurs seasonally in the Gulf of Mexico from nutrient pollution, this naturally occurring oxygen minimum zone is present year-round.
In the Thrash lab, we study the microbiology of northern Gulf of Mexico hypoxia. We are also collaborating with Chief Scientist Dr. Frank Stewart of the Georgia Institute of Technology, who has National Science Foundation funding to study the oxygen minimum zone in the Eastern Northern Tropical Pacific. Scientists from eight different countries, including USA, Canada, Mexico, Iceland, Denmark, Austria, Spain, and Germany, myself included, recently spent three weeks aboard the R/V Oceanus collecting water and sediment to elucidate the organisms and processes involved in forming this peculiar area of the ocean….
Congratulations go to Mike for being awarded a Lerner-Gray Grant for Marine Research from the American Museum of Natural History. Mike will use the grant to explore the use of Oxford Nanopore sequencing to conduct coastal gene expression surveys for various abundant SAR11 bacteria, including LD12. An excellent accomplishment!
Mike, Celeste, and Emily will all be presenting at the 2017 ASM Microbe conference in New Orleans this coming weekend. Here is the info to find them:
Poster Session: AES11 – Freshwater and Marine Microbiology I
Time: 12:15 PM – 2:15 PM
Cultivation and Ecology of Novel SAR11 Taxa from Coastal Louisiana Waters (#700), V. Celeste Lanclos
Metabolic and Physiological Flexibility in a Coastal Isolate from the OM252 Clade of Gammaproteobacteria (#712), Emily Nall
Symposium: 425 – Culturing the Unculturable in a Sequencing Age (Room 352)
Time: 2:30 PM – 5:00 PM
Fresh and Salty: Cultivating Bacteria from the Coast of Louisiana, Michael W. Henson
For the past four months a crew of four rowers and four shore crew members with OAR Northwest, a not-for-profit adventure education organization, have been on a journey of a lifetime on the Mississippi River. After over 100 days of rowing, the crew has traveled from the headwaters of the River in Minnesota to the Gulf of Mexico. They arrived in Baton Rouge on November 16, 2016 and spent a few days visiting LSU and talking to students about their journey.
Just as the state of Louisiana has a special connection with the “Mighty” Mississippi River, the OAR Northwest rowing crew has a special connection with LSU. This is the second OAR Northwest Mississippi River adventure during which rowers have collected water samples for Dr. Cameron Thrash, an assistant professor in the LSU Biological Sciences department. Cameron’s research focuses on relationships between microorganisms and biogeochemical cycles, particularly in marine systems. Thanks to a relationship with the OAR Northwest team that started when founder Jordan Hanssen met Cameron’s family in Washington, and which has developed into an ongoing citizen science project, the Thrash lab is now building a complete microbial “map” of the Mississippi river…