Sulfides down, oxides up
7. August, 2014
Busy times on board the G.O. Sars! We are back at the vent field on the Kolbeinsey Ridge, which we visited with the ROV Aglantha during the first leg. Because the water depth is only 120 meters, the ROV brings samples back to the ship at a fast pace – it takes only about 5 minutes for the ROV to get to the bottom of the seafloor. In between watching the dives in the conference room on the fifth deck or in the container with the pilots, running to the hangar to see what is in the sampling buckets or processing the samples in the labs, there is thus not much time left for movies, the rowing competition (part 2) or blog writing. Luckily, two of our researchers have found some time to tell you about their fascinating projects and what they are doing on board during the cruise.
Ingeborg Økland is a post-doc in geochemistry at CGB, and set out experiments on the seafloor at Jan Mayen yesterday. Read more about her research below.
Ingeborg med inkubatorane klare til å takast ned på havbotnen med ROV’en / Ingeborg ready with the incubators to be send down to the seafloor with the ROV
Eksperiment på havets djup
Eit av måla for dette toktet er å sette ut eksperiment der vi skal undersøkje kva som skjer med sulfid- mineral når dei vert eksponert for sjøvatn og dei mikroorganismane som fins i miljøet. Vi prøver å forstå desse prosessane fordi dei vil kunne påverke miljøet dersom ein skal drive gruvedrift i sulfidavsetjingar på havbotnen. Vi vil undersøke korleis minerala løyser seg opp og endrar seg og om tungmetall vil verte spreidde til sjøvatnet. Eksperimenta blir utført i titan-inkubatorar som består av mange små kammer som vi har fylt med sulfid mineral. Kammera har små hol i veggane der sjøvatnet kan trenge inn og reagere med minerala.
Eit av kammera i inkubatoren som er fylt med sulfid mineral. Sjøvatnet vil komme inn gjennom dei små hola og reagere med minerala.
One of the chambers in the incubator that are filled with sulfides. Seawater will come in through the small holes and react with the minerals.
Inkubatorane festa til ROV’en klare til avreise / The incubators attached to the ROV and ready for departure
Nokre av eksperimenta har blitt satt ut på meir enn 500 m djup i gamle sulfid avsetningar ved Jan Mayen hydrotermale felt og nokre skal setjast ut ved Loke slottet hydrotermale felt på meir enn 2000 m djup. Eksperimenta skal stå der nede i minst eit år før vi kjem tilbake og hentar dei opp igjen og skal undersøkje korleis mineral har endra seg og kva mikroorganismar som kan ha vore med på påverke korleis minerala løyser seg opp og blir omdanna.
Inkubatorane er satt på plass på havbunnen, her skal dei vere minst eit år før vi hentar dei.
Placing the incubators on the seafloor where they will stay for at least one year.
Dette arbeidet er ein del av eit EU-prosjekt, MIDAS, som undersøker mulige miljøkonsekvensar av ressursutvinning i djup-havet og prøver å finne metodar for miljøovervaking slik at utvinning av ressursane vil kunne skje på ein mest mulig miljøvenleg måte.
Experiments in the deep sea
One of the goals for the cruise is to deploy experiment where we will study weathering of sulphide minerals as they are exposed to seawater and the microorganisms in the environment. We want to understand these processes because the might influence the environment during deep sea mining of sulphide deposits. This is a part of an EU-project, Midas, which is investigating how to manage impacts when utilizing deep sea resources.
PhD student Jan Vander Roost is investigating the microbiology of the hydrothermal vent systems. Read here about his stressful hours during the last few hours of ROV-time at the Jan Mayen vent field yesterday…
Number 13
With the aim of cultivating iron oxidizing bacteria on this cruise, my research can be situated within the wonderful field of microbiology. This asks for a finer and more peaceful approach of exploring the seafloor than the standard geology or biology dive (so no hammers, heavy vacuum cleaners and trawlers here). The last dive at the Jan Mayen Vent Fields was reserved for this aim and so, the ROV was equipped with a “biosyringe”. This tool allows a more gentle uptake of the finer material at the seafloor, and is the perfect tool to collect microbial mats (see picture of the biosyringe).
Iron oxidizing bacteria grow and develop rusty organic mats in order to control acidity, nutrient flows and oxygen levels. Consequently, I try to mimic the specific growing conditions within these mats as I try to grow them in the lab.
With the whole ship crew and all scientists on board watching over my shoulder, the pressure was on! It didn’t help that this would be ROV dive number 13. Luckily, I am not superstitious and I could count on an excellent ROV team. We managed to collect a big part of a microbial mat…before the inlet of the biosyringe broke off. Luckily, our sample was then already safe and well in the tummy of the biosyringe.
The ROV coming back on board with Jan’s samples.
Microbial mats sampled in the biosyringe. The red color is from the iron oxides.
Because of some delays in the day schedule, and with the long time of preparing growth vials for my little bacterial preciouses ahead of me, I was set for a long night in the lab. But that didn’t matter. I couldn’t be happier about this successful dive and I only hope my collected iron bacteria will find their new lab environment “meget koselig” too…
