Cruise Report R/V "HEINCKE" Cruise- No. HE-31 ( HK11 ) January - 5 February 1 This report is based on preliminary data! an der Universität Rostock Seestraße 15 D-1119 Rostock- GERMANY Tel +9-31-519- Fax +9-31-519
Cruise No HE-31 ( HK11 ) 1. Cruise No.: HE-31 ( HK11 ). Dates of the cruise: from /1/1 to 5//1 3. Particulars of the research vessel: Name: Nationality: Germany Operating Authority: Alfred-Wegener-Institut für Polar- und Meeresforschung Sektion Biologische Anstalt Helgoland, Postfach 1, D-3 Helgoland. Geographical area in which ship has operated: Baltic Sea between Kiel Bight and northern Gotland Sea 5. Dates and names of ports of call 9/1/1. Purpose of the cruise Joint cruise for Monitoring in the frame of the COMBINE program of HELCOM and long term observation program of IOW. Crew : Name of master: R. Voss Number of crew: 1. Research staff: Chief scientist: Klaus Nagel Participants : /1-5//1 Susanne Busch Ursula Hennings Jan Donath Lars Kreuzer Ines Hand Ingo Schuffenhauer Uwe Hehl Erika Trost /1-9/1/1 Birgit Sadkowiak 9. Co-operating institutions: All institutions dealing with the COMBINE program of HELCOM 1. Scientific equipment : CTD water samplers plankton net - / 1 -
Cruise No HE-31 ( HK11 ) 11. General remarks and preliminary results The cruise HE31 was a joint cruise between the German contribution to the COMBINE program of HELCOM and the long term data series of IOW. The area under investigation covered the Baltic Sea between Kiel Bight and the northern Gotland Basin as shown in the attached maps. Marine meteorological, hydrographic, chemical and biological investigations were performed at stations. The measurements were supplemented by continuous registration of standard meteorological parameters as well as surface water temperature and salinity. For selected stations, which are characteristic for different regions of the Baltic Sea, preliminary data of hydrographic and hydrochemical parameters in the surface and the near-bottom layer are compiled in the attached tables. These results are also compared with mean values calculated from the measurements performed during the February cruises of the years 1993 to. Except some short periods on /1/1, 3/1/1 and //9 with wind speeds of of about m/s and heavy snow showers, the weather during the cruise was rather calm for this time of the year. Generally wind speed varied between 5 m/s and 15 m/s with only short periods of lower or higher values. Due to the passage of some low pressure areas, no predominating wind direction was observed. As the cruise started at the end of an longer period of very cold days with minimum air temperatures far below -1 C, large ice fields were found in the coastal areas of the western Baltic Sea and the Pomeranian Bight. During the cruise air temperature increased and varied around C in all areas covered. Surface water temperature increased from -.5 C in the Lübeck Bight to 1.5 C in the Arkona Basin and are lower than expected from long term observations. In the central areas of the Baltic Sea surface water temperatures varied between C and 3 C. Salinity in the surface layer was within the values expected from long term measurements in all regions of the Baltic Sea and varied between in all areas except Kiel and Mecklenburg Bight. A halocline was observed between m and 5 m in the Arkona Basin, slightly below 5 m in the Bornholm Basin and between m and m in the Eastern and Western Gotland Basins. Salinities measured in the bottom layer in the central areas of the Baltic Sea are in the range expected from long term observations and varied around 1. However, salinities in the bottom layer of the western Baltic ( 13-1 ), Mecklenburg Bight ( below 1 ) and in the Arkona Basin ( 1-13 ) are significantly lower than expected. The western Baltic Sea and the Arkona basin were well oxygenated down to the sea floor with oxygen concentrations of more than ml/l at most stations. Oxygen concentration in the Bornholm Basin dropped below ml/l at depths exceeding m, but increased again in the bottom layer, where up to 3.5 ml/l O were measured. Anoxic conditions had been observed only at 5 station in the central eastern Gotland Basin and at the Karlsö Deep station at depths below 1 m to 11 m. In the bottom layer of the eastern Gotland Basin concentrations of up to. mg/l H S were found. In the Karlsö Deep hydrogen sulphide concentration was rather low (. mg/l H S ). - 3 / 1 -
Cruise No HE-31 ( HK11 ) Nitrate concentrations in the surface layer were normal for this time of the year and vary between 3 µmol/l and almost 5 µmol/l, which is within the range expected from long term observations for most stations. At most stations, phosphate concentrations in the surface layer were close to those found at the same time one year ago and are in good agreement with the values expected from IOW's long term data series. However, at some stations in the southern Baltic Sea and the eastern Gotland Basin significantly lower Phosphate concentrations were measured. In the bottom layer concentrations of nitrate and phosphate are controlled by the presence of oxygen or hydrogen sulphide and were found in the expected range for most stations. Due to the ongoing stagnation phosphate concentrations at the bottom were significantly higher ( 5 µmol/l ) and correlate with relatively high amounts of H S. Stations in the Bornholm Basin have been analysed two times, on 31/1/1 and four days later on //1. The measurements showed that the bottom layer of the Bornholm Basin is filled with warm and high saline water with relatively high oxygen concentrations as a result of the last saltwater inflow some weeks ago. By comparison of the two data sets the propagation of this water mass from the Bornholm Basin into the Słupsk Channel can be followed ( see attached figures ). Samples for the determination of HCH, CKW/PAK and Phyto- and Zooplankton were taken for later analysis in the laboratory. During the cruise two moorings have been recovered or deployed : - Sediment trap recovered 5 19.11' N, 1.' E - Sediment trap deployed 5 19.' N,.5' E Klaus Nagel Scientist in charge Attachments : - station charts - tables of preliminary results for selected stations (surface layer and near bottom layer) - comparison of actual data with mean values calculated from the measurements during the February cruises of the years 1993 (surface layer and near bottom layer) - transects of temperature, salinity and oxygen concentration between Kiel Bight and northern Gotland Sea - map showing oxygen concentrations in near the bottom water layer ( hydrogen sulphide concentration is given as negative O equivalents ) - transects of temperature, salinity and oxygen concentration in the Bornholm Basin on 31/1/1 and //1 - / 1 -
Cruise No HE-31 ( HK11 ) HE11 / map 1 monitoring.1.1 -..1 55 stations / 1 repeated stations TF3 TF31 TF TF1 TF11 TF1 TF TF TF1 TFO5 Longitude [ ] TF TF3 TF1 TF115 TF9 TF11 TF113 TF1 TF15 TF1TF13 TF15 TF19 ABBoje TF111 TF11 TF11 TF15 TF15 TF1 TF1 TF1 5 5 5 5 5 55 55 55 55 55 5 5 5 Latitude [ ] -5-1 -15 - -5-3 -35 - -5-5 -55 - -5 - -5-1 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research 1. 1.5 11. 11.5 1. 1.5 13. 13.5 1. 1.5 15. - 5 / 1 -
Cruise No HE-31 ( HK11 ) HE11 / map monitoring.1.1 -..1 55 stations / 1 repeated stations TF1 TF TF11 TF1 TF13 TF1 TF TF TF1 TF5 Longitude [ ] TF5 TF55 TF59 15. 15.5 1. 1.5 1. 1.5 1. 1.5 19. 19.5..5 1. 1.5. TF53 TF5 TF3 TF TF TF TF TF1 sch1 sch 55 5 5 5 5 5 5 59 59 Latitude [ ] 1 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research -5-5 -5-1 -15-15 -15 - -5-5 -5-3 -35-35 -35 - -5-5 - / 1 -
Cruise No HE-31 ( HK11 ) Preliminary results of hydrographic and hydrochemical parameters at selected stations - surface layer - Station Stat.Name Temp. Salinity NO 3 *) PO SiO O Date Stat.No. **) C µmol/l µmol/l µmol/l ml/l Kiel Bight /1/1 Mecklenburg Bight /1/1 Arkona Basin /1/1 Bornholm Deep 31/1/1 Stolpe Channel 31/1/1 SE Gotland Basin 31/1/1 Gotland Deep 1//1 Fårö Deep //1 Landsort Deep TF3 TF1 TF113 1 TF13 35 TF 3 TF59 TF1 TF 51 TF.1 1.9 5.. 1.1..1..3.1 1. 9.19 1.5..5.5 13.5 9..5.3 3..55 1. 9..1. 3..31 1...91.5.1.1 1.9...35 3.1.31 9...1. 3.9.5 13.3. Karlsö Deep 3//1 TF5 5.3. 3.55.9 1.9. *) NO 3 is given as sum of NO 3 - and NO - **) see attached maps (in most samples NO - was present only in traces) - / 1 -
Cruise No HE-31 ( HK11 ) Preliminary results of hydrographic and hydrochemical parameters at selected stations near bottom layer - Station Stat.Name Depth Temp. Salinity NO 3 *) PO SiO O Date Stat.No. **) m C PSU µmol/l µmol/l µmol/l ml/l Kiel Bight /1/1 Mecklenburg Bight /1/1 Arkona Basin /1/1 Bornholm Deep 31/1/1 Stolpe Channel 31/1/1 SE Gotland Basin 31/1/1 Gotland Deep 1//1 Fårö Deep //9 Landsort Deep TF3 TF1 TF113 1 TF13 35 TF 3 TF59 TF1 TF # TF 1. 1. 5.. 13.3.3.1 1... 19.5.93 5.5 13.. 1,1. 5. 9.3 1..9 1.5. 3. 9 9.3 1.55. 1.5.3..99 1.1.9 1.3 33..31 33.31 1.5 - / -.5. -5.93 ( H S ) 1.5 11. - / -.55 1.5 -.9 ( H S ) Karlsö Deep 3//1 TF5 5 15 5.3 9. - / - 5. 5. -. ( H S ) *) NO 3 is given as sum of NO 3 - and NO - **) see attached maps (in most samples NO - was present only in traces) - / 1 -
Cruise No HE-31 ( HK11 ) Selected stations / February cruises : near-surface layer Temperature ( C ) 1 Salinity 1 1 1 1 1 Nitrate ( µmol/l ),9 Phosphate ( µmol/l ),,,,5,,3,,1 9,5 Oxygen ( ml/l ) 9,,5, TF3 TF1 TF113 TF13 TF TF59 TF1 TF TF TF5 K. Nagel \ st_1s \ //1 Means & s.dev. February cruises 1993 - Monitoring cruise February 9 Monitoring cruise February 1-9 / 1 -
Cruise No HE-31 ( HK11 ) Selected stations / February cruises : near-bottom layer Temperature ( C ) Salinity 1 1 1 1 1 1 1 Nitrate ( µmol/l ) 1 Phosphate ( µmol/l ) 5 3 1 Oxygen ( ml/l ) **) - - - TF3 TF1 TF113 TF13 TF TF59 TF1 TF TF TF5 **) : H S was converted to negative O equivalents K. Nagel \ st_1b \ //9 Means & s.dev. February cruises 1993 - Monitoring cruise February 9 Monitoring cruise February 1-1 / 1 -
Cruise No HE-31 ( HK11 ) HE91 monitoring.1.1 : -..1 19:5 UTC TF3 TF31 TF1 TF11 TF1 TF TF TF1 TF3 TF115 TF11 TF113 TF15 TF1 TF1 TF15 TF1 TF1 TF1 TF TF11 TF1 TF13 TF1 TF TF5 TF59 TF55 TF53 TF5 TF3 TF TF TF1 TF TF -1-3 -5 - -9-11 -13-15 -1-19 -1-3 Temperature [ C] -5 5 1 15 5 3 35 5 1 9 5 3 1-1 -1-3 -5 - -9-11 -13-15 -1-19 -1-3 Salinity [psu] -5 5 1 15 5 3 35 5 3 1 19 1 1 1 15 1 13 1 11 1 9 5.srf -1-3 -5 - -9-11 -13-15 -1-19 -1-3 Oxygen [ml/l] -5 5 1 15 5 3 35 5 Distance [n.m.] 1 Leibniz Institute for Baltic Sea Research, Department Physical Oceanography Jan Donath 9 5 3 1-11 / 1 -
Cruise No HE-31 ( HK11 ) HE11 / map O monitoring.1.1-5..1 oxygen bottom - concentration [ml/l].3..93.91 5..3 1.9 Longitude [ ] 3.. -.(HS).5 -.9(HS) -.51(HS) -5.95(HS) Gotland 5 55 5 5 5 59 Latitude [ ] LATVIA DENMARK SWEDEN Öland Ystad -3 - -9-1 -15-1 -1 - - Bornholm POLAND Gdynia Kaliningrad -3-33 -3-39 - -5 - -51-5 GERMANY 1 Department Physical Oceanography Jan Donath Leibniz Institute for Baltic Sea Research 1 11 1 13 1 15 1 1 1 19 1-1 / 1 -
Cruise No HE-31 ( HK11 ) HE11 monitoring 3.1.1 3:53-31.1.1 1:31 UTC TF TF11 TF1 TF13 TF1 TF TF -1-1 -3 9 - -5 - - - 5-9 Temperature [ C] -1 1 3 5 3-1 - -3 - -5 - - - -9 Salinity [psu] -1 1 3 5 1 1 1 15 1 13 1 11 1 9-1 - -3 - -5 - - 5 - -9-1 1 3 5 Distance [n.m.] Bornholm1.srf Oxygen [ml/l] 1 Leibniz Institute for Baltic Sea Research, Department Physical Oceanography Jan Donath 3 1-13 / 1 -
Cruise No HE-31 ( HK11 ) HE11 monitoring um Bornholm zurück..1 :1-1: UTC TF TF11 TF1 TF13 TF1 TF TF -1-1 -3 9 - -5 - - - -9 Temperature [ C] 5-1 1 3 5 3-1 - -3 - -5 - - - -9 Salinity [psu] -1 1 3 5 1 1 1 15 1 13 1 11 1 9-1 - -3 - -5 - - 5 - -9-1 1 3 5 Distance [n.m.] BORNHOLM.srf Oxygen [ml/l] 1 Leibniz Institute for Baltic Sea Research, Department Physical Oceanography Jan Donath 3 1-1 / 1 -