Cruise R/V BILIM
September-October 2000

R/V Bilim carried out  a joint survey of two legs in the Black Sea to study the chemistry of the sub-oxic zone and the effectcs of the physical processes on the dynamics of the ecosystems during autumn. Specific objectives of the cruises were:

• to understand the chemistry of the sub-oxic zone,
• to describe, explain and understand the mechanisms of the circulatory features in the southeastern part of the basin,
• to collect nutrient, chrolophyll-a, oxygen, production and light profile data to characterize basic state of the ecosystem,
• to collect phytoplankton and zooplankton data in order to understand effect of the physical processes on the distribution and functioning lower trophic levels of the ecosystem,
• to estimate Calanus egg production,
• to describe planktonic pigments concentration and distribution,
• to understand DMSP and DMSO production and consumption.

Scientists from Turkey, USA, Ukraine and Netherlands participated the cruises.

LEG I

The leg was dedicated to the measurements to study the physico-chemical reactions and biochemical properties of the sub-oxic zone. The leg started on September 22 and lasted on October 1, 2000. The parameters measured during the cruise were: 

The station location of Leg I

The cruise participants:
Prof. Ilkay Salihoglu  (IMS-METU)
Prof. Suleyman Tugrul (IMS-METU), Chief Scientist
Dr. Semal Yemenicioglu (IMS-METU)
Selahattin Erdogan (IMS-METU)
Oguz Yigiterhan (IMS-METU)
Amy Callahan (Washington University, USA)
Barbara Paul (Washington University, USA)
Mehmet Demirel (IMS-METU)
Saim Cebe (IMS-METU)
Esabil Kakac (IMS-METU)

LEG II

In order to achieve its objectives the following measurements were done during the cruise:
Physical measurements
The CTD data were obtained using SBE 11plus also equipped with fluometer and transmissivity sensors. The CTD  were carried out from surface down to 550 m. Irradiance measurements (upward and downward) were carried out by LI-1800UW model spectroradiometer from surface down to 1% light level at 5 stations visited by noon time.
Chemical measurements
Dissolved nutrients, dissolved oxygen, H2S and chlorophyll-a measurements were performed on every second CTD stations. Sampling depths were chosen according to sigma-t levels.
Biological measurements
Phytoplankton (sampling by Niskin bottles) and zooplankton (net sampling) measurements were carried out at every third CTD stations. Taxonomic analysis will be carried out later.
Sub-mesoscale biomass of four different sized (100-200, 200-500, 500-1000, 1000-2000 mm sized) planktonic organisms were sampled.
The effects of food size and availability on the Calanus euxinus egg production were determined. In addition to this study, culturing of the Calanus euxinus in the laboratory tried and egg, feccal pellet production and excretion of Calanus will be determined in the laboratory.
Samples were collected to study the distribution of various methylated sulfur compounds in seston, dissolved matter and zooplankton.
Pigment samples were collected along the 3 transects in the Black Sea from surface, sub-surface and below the sub-surface layer for HPLC analysis.
Primary production measurements using ¹⁴C technique (both using simulated in situ and artificial incubation) were done at 2 stations in order to determine the photosynthetic carbon production rates.

Station network for October 2000 cruise

CRUISE TEAM:
Dr. Sukru Besiktepe (IMS-METU), Chief scientist
Dr. Sengul Besiktepe (IMS-METU)
Dr. Dilek Ediger (IMS-METU)
Dr. Kem Tang (Netherlands)
Elif Eker (IMS-METU)
Adil Sezer (IMS-METU)
Murat Telli (IMS-METU)
Saim Cebe (IMS-METU)
Esabil Kakac (IMS-METU)
Sahin Bulut (IMS-METU)
Hasan Uslu (IMS-METU)
Tahir Tutsak (IMS-METU)