On board of Re­search Ves­sel Met­eor in the Black Sea

In the fo­cus of the study pro­posed here are in situ meas­ure­ments of fluxes and turnover of meth­ane and sul­fur at seep sys­tems of the Black Sea, as well as an in­vest­ig­a­tion of the mi­cro­bial di­versity and func­tion in a per­man­ently an­oxic set­ting, es­pe­cially that as­so­ci­ated with fluid flow and gas seep­age.In the North­ern Black Sea, a large vari­ety of act­ive meth­ane seeps have been iden­ti­fied at depths from 100-3000 m, in­clud­ing act­ively gas emit­ting mud vol­ca­noes, and unique mi­cro­bial reefs. The main ob­ject­ives of MI­CRO­HAB are to map spe­cific mi­cro­bial hab­it­ats at high res­ol­u­tion, to quantify the com­pos­i­tion, dis­tri­bu­tion and de­vel­op­ment of mi­cro­bial com­munit­ies in the per­man­ently an­oxic Black Sea, to and to ob­tain in­sight in ele­ment cyc­ling and ex­port at dif­fer­ent types of fluid seeps in the Black Sea.

The ex­ped­i­tion “MI­CRO­HAB”con­trib­utes to the GEO­TECH­NO­LO­GIEN pro­gram “Meth­ane in the Geo-Bio-Sys­tem” MUMM II by study­ing the mi­cro­bi­o­logy and biogeo­chem­istry of meth­ane and sul­fur turnover by in situ tech­no­lo­gies, as well as to Work Pack­age“An­oxic mi­cro­bial hab­it­ats” of the EU FP6 In­teg­rated Pro­ject HER­MES which deals with the biod­iversity of hot­spot eco­sys­tems at Europe’s con­tin­ental mar­gins. We left the har­bor of Istan­bul in the morn­ing of the 23 Feb­ru­ary. Not even the re­l­at­ively dense fog was able to hide the beauty of the Bosporus coast­line. Un­for­tu­nately the Black Sea waited for us with strong winds and high waves so that the 28 new sci­ent­ists on board chose a light din­ner and ear­lyrest. We ar­rived at the first site, the gas seeps at the North-West­ern slope of the Crimea Pen­in­sula in the even­ing of the 24 Feb­ru­ary. After spring-time tem­per­at­ures in Istan­bul, we had to ac­cus­tom to -5°C out­side. Due to tech­nical prob­lems with the ROV QUEST we star­ted in­stead with a series of TV-guided mul­ticorers across the oxic-an­oxic bound­ary from 120 m wa­ter depth down to 170 m for our new part­ner in HER­MES, the Ukrain­ian In­sti­tute of Bio­logy of the South­ern Seas (IBSS). Katya Ivan­ova from the Benthos Eco­logy De­part­ment looks for changes in the fauna with re­gard to oxy­gen avail­ab­il­ity. On the 25 Feb­ru­ary the weather im­proved con­sid­er­ably and we planned the first dive of the AUV As­terX (Ifre­mer) car­ry­ing the mult­i­beam echo­sounder Sim­rad EM2000 (GeoAzur) above the gas seeps in 150-300 m wa­ter depth on the slope of the Crimea pen­in­sula. The aim was to map the fam­ous car­bon­ate reefs formed by meth­an­o­trophic mi­croor­gan­isms in this re­gion. Un­for­tu­nately it was dis­covered that the AUV has severe tech­nical prob­lems, and our Ifre­mer team on board is work­ing hard on solu­tions ever since. In­stead we worked with the ship based Kongs­berg EM 710 Mult­i­beam to pre­pare the first ROV dive to the mi­cro­bial reefs. The task was to do video-mo­sa­ick­ing and sampling of the MET­ROL and GHOSTDABS fields which were the tar­gets of many pre­vi­ous in­vest­ig­a­tions of the mi­cro­bial reefs fo­cus­ing on their or­ganic and in­or­ganic geo­chem­istry and geo­bi­o­logy. Due to the tech­nical prob­lems with ROV QUEST (MARUM) the video-mo­sa­ick­ing was can­celed, but we ob­tained very in­ter­est­ing push cores from between a chim­ney field show­ing vari­ous forms of sub­sur­face mats and mi­cro­bial biofilms, and quite gassy sed­i­ments. We con­tin­ued to the Sor­okin Trough NE of Crimea on the 26 Feb­ru­ary.

This area is known for its many act­ive mud vol­ca­noes, which have been pre­vi­ously stud­ied by the TTR pro­gram (IOC/​UN­ESCO) and dur­ing MET­EOR ex­ped­i­tion M52 “Mar­gasch”. We had planned to fo­cus on the Dv­urechenskii mud vol­cano (DMV), a flat-topped and very act­ive mud vol­cano in the Sor­okin Trough. The 27 and 28 Feb­ru­ary we spent map­ping the mud vol­cano with the EM120 to plan the dives, and with de­ploy­ment of grav­ity corers equipped with in situ tem­per­at­ure probes. As part of the HER­MES pro­gram, Tom Feseker of IFRE­MER/​AWI is study­ing the in situ tem­per­at­ures of the sur­face and sub­sur­face muds in re­la­tion to the mor­pho­logy and chem­istry of the mud vol­cano for a bet­ter idea of the fluid flow and its causes and ef­fects. We have dis­covered a small el­ev­a­tion in the NE cen­ter of the mud vol­cano where re­l­at­ively fresh mud flows are vis­ible and free gas is es­cap­ing when the sea­floor is touched by the ROV or our in­stru­ments. Tom was able to con­firm that this is the warmest spoon the DMV by grav­ity cor­ing. The ring marks the gassy mound, which we are cur­rently sampling. Between 1 and 4 March we have mainly con­cen­trated on TV MUC and grav­ity core sampling of the cen­ter and North­ern and South­ern rim of the DMV. We are ana­lyz­ing the biogeo­chem­ical sig­na­tures of vari­ous mi­cro­bial and geo­chem­ical pro­cesses in sed­i­ments con­nec­ted to meth­ane turnover within and out­side of the mud vol­cano. Thanks to the hard work of the ROV QUEST tech­nical team on board, the deep-wa­ter ro­bot QUEST of MARUM is cur­rently diving to de­ploy the mi­cro­sensor pro­filer meas­ur­ing sulf­ide fluxes and pH pro­files to­gether with the tem­per­at­ure probe sys­tem along a tran­sect from the act­ive cen­ter to the out­side of DMV. Des­pite the many tech­nical prob­lems we are mak­ing good pro­gress with the work and have a good time on board sup­por­ted by the ex­cel­lent cap­tain and crew of MET­EOR.


With our best greetings to families, friends and colleagues on land – the MICROHAB team.