Mesopelagic fish collected during Maria S. Merian cruise MSM26, spring 2013

Mesopelagic fish were collected using a 1 m**2 Double-MOCNESS (Multiple Opening and Closing Net and Environmental Sensing System) and 4.5 m**2 IKMT (Isaacs-Kidd midwater trawl). The main portion of the IKMT was 20 mm knotted nylon, and the tail bag was 3 mm knotless nylon. Oblique IKMT tows were made to a maximum depth of 500 m at a tow speed of 3.5 knots. The original cruise plan intended for nighttime IKMT tows, but tow times varied due to operational constraints. The MOCNESS was equipped with 20 nets of 333 µm mesh size; 10 nets per side. The towing speed was 2 knots. Samples were collected to a maximum depth of 1250 m. The first oblique nets sampled from the surface to the max depth, and the other nets sampled depth stratified bins of the water column. MOCNESS hauls were performed during day and night to investigate diel vertical migrations. Mesoplelagic fish were processed on board. All fish were picked from all IKMT nets, most oblique MOCNESS nets, and the left side nets of the depth stratified MOCNESS samples. The Depth stratified nets from the right side of the MOCNESS frame were preserved in 5 % formalin for future quantitative analyses of the nekton. Fish were identified to the lowest possible taxa using Whitehead et al. (1984) and Fahay (2007). Standard length of each fish was measured to the nearest 0.1 mm using a digital caliper. Measured and identified fish were frozen in an -80 °C freezer, and shipped to the University of Hamburg at the end of the cruise.

Stable C and N isotopes and percent C as well as N composition of plankton from the North Atlantic

Elemental C and N percent composition and natural abundance of stable C and N isotopes of plankton species and/or size-fractions collected in several cruises on the N Atlantic Ocean from Greenland to Norway and around Iceland. Determinations included key copepod and krill species. Lipid extraction was performed in some samples to determine carbón isotope depletion factors.

Bacterial abundance in the eastern Mediteranean Sea in August and September 2008 during SES_GR2

The SES_GR2_MICROBIAL PARAMETERS dataset is based on samples collected in the framework of the project SESAME, in the Ionian, Libyan and Aegean Sea during August-September 2008. The objectives were to measure the standing stocks and calculate the production of the microbial compartment of the food web, describe the vertical distribution pattern and characterize its structure and function through the water column. Subsamples for virus, heterotrophic bacteria and cyanobacteria (Synechococcus spp. and Prochlorococcus spp.) counting were analyzed using a FACSCalibur (Becton Dickinson) flow cytometer equipped with a standard laser (488 nm) and filter set and using deionized water as sheath fluid. Fluorescent beads with a diameter of 0.97 ?m (Polysciences) were added to each sample as an internal standard, and all parameters were normalized to the beads and expressed as relative units. SYBRGreen I stain (Molecular Probe) was used to stain viral and heterotrophic bacterial DNA. Viruses were counted according to (Brussaard 1984). In order to avoid bulk consentrations of viruses samples we dilluted to Tris-EDTA (pH=8,0) buffer to a final sollution of 1/5 to 1/100. Total abundance and nucleid content classes were calculated using the Paint-A-Gate software (Becton Dickinson).

Bacterial production in the eastern Mediteranean Sea in August and September 2008 during SES_GR2

The SES_GR2_MICROBIAL PARAMETERS dataset is based on samples collected in the framework of the project SESAME, in the Ionian, Libyan and Aegean Sea during August-September 2008. The objectives were to measure the standing stocks and calculate the production of the microbial compartment of the food web, describe the vertical distribution pattern and characterize its structure and function through the water column. Bacterial production was estimated by the 3H-leucine method (Kirchman et al. 1986, Kirchman 1993). At each depth, duplicate samples and a control were incubated with 20 nM L-[4,5 3H]-leucine. Samples were incubated in the dark, at in situ temperature.