From April 15 to May 15, 2003, Voyage 172 of the R/V Knorr to the Black Sea was divided into three legs. The first leg (Leg 7) was from 15 April to 25 April, 2003; the second (Leg 8) was from 25 April to 10 May, 2003; and the third (Leg 9) was from 10 May to 15 May, 2003. The port of arrival and departure was Istanbul. Drs. James W. Murray and George W. Luther, III were the co-chief scientists on leg 7. Dr. George W. Luther, III was chief scientist for legs 8 and 9.

On Leg 8 we visited Sevastopol on 27 April (Easter Sunday in the Orthodox Religion) for a Good Will Port Call. Captain A. D. Colburn, III and Chief Scientist George W. Luther, III presented the National Science Foundation Flag and other gifts to Ukrainian scientists and colleagues from the Marine Hydrophysical Institute, the Institute of Biology of the Southern Seas and Moscow State University. A tour of the R/V Knorr was also provided to the Ukrainian scientists. They were impressed with all aspects of the visit and we view this visit as a great success for further interactions with them.

The research party for the cruise consisted of 56 scientists representing 20 academic institutions from 8 countries (USA -26; Turkey -21; Ukraine -3; Germany -2; The Netherlands -1; Thailand -1; Switzerland -1) as shown in Table 1. The foreign participants are highlighted in bold.

The coordinates of the station locations are given in Table 2 (A-C) and shown in the composite colored Figure for all cruise legs (172/7; 172/ 8; 172/9). Dr. Sergey Konovalov from the Marine Hydrophysical Institute in Sevastopol compiled this figure. The event logs for these three legs are given in Tables 3 through 5. Each event ID gives the voyage and leg, the station number, the sequential event at that station, the date and time (in Greenwich mean time). Thus K17270020034151445 was a CTD cast during R/V Knorr Voyage 172 Leg 7 at station 002. It was event 003 on April 15 at 1445Z.

The data to be delivered and the date of expected delivery are given in Table 6. Dr. George W. Luther, III has already provided the hydrographic data (CTD, ADCP) to the Turkish Navy. Lt. Mustafa Özyalvaç came to the R/V Knorr after legs 7 and 9 for data and discussion.

The scientific program of this research cruise in the Black Sea was organized around the first three main themes funded by the National Science Foundation. The last two themes were from our Turkish colleagues, who provided appropriate station locations for legs 172/8 and 172/9. Samples and real time data were collected for all themes.

1. The first was a study of the biogeochemical distributions in the suboxic zone, which is the zone of contact between the oxic surface water and the anoxic or sulfidic deep water. The depth of this suboxic zone ranges from 20-50m, but can be affected by Mediterranean Sea inflow waters in the southwest Black Sea – this causes temperature and oxygen concentration fluctuations know as “fingering”. Samples were collected using the rosette-CTD as well as a pump profiling system. An in situ electrochemical analyzer was also used to determine oxygen and sulfide concentrations in real time. As part of this theme, we collected hydrographic data (T,S), oxygen (O2), sulfide (H2S), nitrate, carbon dioxide, manganese (Mn), elemental sulfur (S8) data.

2. The second was to study how manganese, nitrogen and sulfur chemistry interact and thus stabilize the suboxic zone and oxidize sulfide to elemental sulfur. These biogeochemical processes were studied by manipulating waters from the Black Sea with addition of Mn and N species.

3. A third goal was to study microbial distribution and processes in the suboxic and sulfidic zones. We collected water samples from suboxic to deep sulfidic waters, suspended sediment samples from the water column and bottom sediment cores to measure organic chemical biomarkers, which are to be coupled with molecular biology analyses.

4. A fourth goal was to obtain sediment cores for Turkish colleagues who desired to study the mineralogy and microbiology of primarily shelf and slope sediments.

5. A fifth goal was to collect hydrographic data (T,S) for a Turkish colleague, Dr. Temel Oguz, who could not be aboard. His goal was to document the nature of the physical currents in the Eastern basin of the Black Sea.