Page path:

In the middle of the At­lantic Ocean: Re­search ves­sel Maria S. Merian

First cruise re­port from the Ger­man re­search ves­sel Maria S. Merian
 
On the 23rd of Janu­ary the Ger­man re­search ves­sel Maria S. Merian set out with 14 sci­ent­ists, 9 ROV (re­mote op­er­ated vehicle) crew mem­bers and 21 crew mem­bers from Fort de France, Mar­ti­nique, to in­vest­ig­ate the Log­atchev hy­dro­thermal vent field at 14°45`N, 44°58`W on the Mid-At­lantic Ridge. This cruise is part of the Ger­man Sci­ence Found­a­tion’s Pri­or­ity Pro­gram “From Mantle to Ocean” (DFG-SPP 1144) in which geo­lo­gists, fluid chem­ists, geo­phys­i­cists and bio­lo­gists work to­gether to un­ravel the mass and en­ergy trans­fer tak­ing place from the earth’s mantle to the ocean.
We have the ROV Jason II from the Woods Hole Ocean­o­graphic In­sti­tu­tion on board, which we will use to re­cover long-term ex­per­i­ments left by a pre­vi­ous cruise with R/​V Met­eor, re-de­ploy in­stru­ments and col­lect vari­ous types of samples from the 3000 m deep sea­floor of the hy­dro­thermal vent field.
Jason II has never been used with a Ger­man re­search ves­sel be­fore, and al­though it still seems a mir­acle to us that we man­aged to ad­apt this com­plex sys­tem based on inches, pounds and Amer­ican power re­quire­ments to a met­ric ship, we were still able to mo­bil­ize within only 3.5 days. This could only be ac­com­plished with the ex­cep­tional sup­port in every re­spect of the ship’s crew. After suc­cess­fully test­ing Jason II with a “har­bor dip” on the morn­ing of the 23rd Janu­ary, we were ready to leave port ac­cord­ing to sched­ule. Dur­ing the transit to the Log­atchev field, the sci­ent­ists were very busy set­ting up their labor­at­or­ies while the ROV team had the chance for ad­di­tional test­ing of their vehicle. After 3.5 days of transit we ar­rived on the 26th Janu­ary at the Log­atchev field. The weather is good, the sea is calm, and the con­di­tions for diving with a ROV are fine.
The first dive las­ted 8 hours and proved suc­cess­ful, as hot hy­dro­thermal flu­ids were meas­ured and col­lec­ted from the Ir­ina II chim­ney struc­ture, which we de­term­ined for the first time to emerge with tem­per­at­ures of up to 350°C. Fluid samples col­lec­ted with ti­tanium syr­inges served for on­board ana­lyses of gases (hy­dro­gen, sulf­ide and meth­ane) and other or­ganic and in­or­ganic com­pounds. The first cul­ture ex­per­i­ments of the mi­cro­bial com­munit­ies were star­ted. Mus­sels which host chemo­syn­thetic sym­bionts in their gill tis­sues were col­lec­ted in or­der to per­form in­cub­a­tion ex­per­i­ments on board. Other mac­ro­fauna, e.g. limpets, shrimps and brittle stars will be ana­lysed in the home labor­at­or­ies.
The second dive proved equally suc­cess­ful as geo­phys­ical in­stru­ments were re­covered after hav­ing been on the sea­floor for 20 months. The ocean bot­tom tilt meter (OBT) and ocean bot­tom pres­sure meter (OBP) re­cor­ded local sea­floor dy­nam­ics re­lated to hy­dro­thermal activ­ity and tec­ton­ics. The two in­stru­ments were still in a good con­di­tion and read­ings of the logged data in­dic­ated that they had worked suc­cess­fully for more than a year. The re­cov­ery of these data there­fore marks a mile­stone for reach­ing the time-series re­lated goals of the SPP 1144. An­other ma­jor tar­get of this dive was the “re-loc­a­tion” of a pre­vi­ously ob­served site with mi­cro­bial mats which is loc­ated next to marker “Anya” north-west of the Ir­ina II struc­ture. Here we po­si­tioned an in-situ pro­filer that meas­ures the ho­ri­zontal gradi­ents of en­vir­on­mental key para­met­ers con­trolling the hy­dro­thermal mi­cro­bial com­munit­ies, such as con­cen­tra­tions of hy­dro­gen sulf­ide, hy­dro­gen, oxy­gen, tem­per­at­ure and pH at a mi­cro-scale. This pro­filer will later be used at dif­fer­ent hy­dro­thermal en­vir­on­ments in­clud­ing mus­sel beds. The mi­cro­bial mat was also sampled with push cores for ex-situ ex­per­i­ments on mi­cro­bial turnover pro­cesses and for ge­n­omic ana­lysis of the mi­cro­bial pop­u­la­tion.
While Jason II dived dur­ing day time, we ded­ic­ated our first night in the re­search area to the de­tec­tion of the hy­dro­thermal plume in the wa­ter column by CTD casts.
An un­usual in­cid­ent on Sunday elu­cid­ated very clearly how small and vul­ner­able we are in the middle of the ocean. A Ger­man sail­ing boat which was only 35 nm miles apart from our po­s­i­tion at Log­atchev had a broken mast and asked for sup­port with food, wa­ter and diesel in or­der to be able to con­tinue sail­ing with re­duced speed to their des­tin­a­tion in the Carib­bean. We in­ter­rup­ted our re­search and searched for the only 10.5 m long boat which we met around mid­night. The two sail­ors were well and we sup­plied them with what they needed be­fore they con­tin­ued on their way and we took on with our work. We wish them good luck and hope that they will ar­rive safely!

With only 14 sci­entific par­ti­cipants, the sci­ence group is com­par­ably small and the de­mands of shift work dur­ing day­time dives and work on samples and ex­per­i­ments dur­ing night­time can eas­ily build up a chal­lenge for every­body. However, the co­oper­a­tion between ROV team, ship’s crew and sci­ent­ists is ex­cel­lent and we are all in a very good mood and are look­ing for­ward to an­other 10 very suc­cess­ful work­ing days at Log­atchev.

We are all in good health and send our best wishes.

Christian Borowski and the MSM 04/3 shipboard party.

29th Janu­ary 2007
The ROV “Jason 2” be­ing launched over the side of R/​V Maria S. Merian.
Po­s­i­tion­ing of the pro­filer on a mi­cro­bial mat.
Sampling hot flu­ids from eth Ir­ina II main struc­ture with a ti­tanium syr­inge.
Re­cov­ery of the OBP after 20 months ex­pos­ure to sea­floor.
Sail­ing boat with broken mast along­side Maria S. Merian in the middle of the At­lantic Ocean.
Back to Top