Ingestion rate and egg production of copepods collected in the upper 20m in the eastern Mediterranean Sea in Oktober 2008

This dataset based on samples taken during October 2008 in Dardanelles Straits, Marmara Sea and Bosporus Straits at the third priority stations. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 50 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Oithona spp., Clausocalanus furcatus, Acartia clausi and Oncaea spp. and in one cladoceran species Penilia avirostris according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs/female/day) collected in the 0-20m layer. Copepod egg production was measured for the copepods Clausocalanus furcatus, Paracalanus parvus,Acaria clausi. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mg/m**2/day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).

Ingestion rate and egg production of copepods collected in the upper 100m in the eastern Mediterranean Sea in March and April 2008 during SES_GR1

The phytoplankton dataset is based on samples taken during March-April 2008 in Libyan Sea, Southern Aegean Sea and Northern Aegean Sea. Ingestion rates were estimated from experiments performed at all the third priority stations during the cruise according to DoW of Sesame project. Copepods for the experiments were obtained with slow non-quantitative tows from the upper 100 m layer of the water column using 200 µm mesh size nets fitted with a large non-filtering cod end. For the grazing experiments we used the following copepod species: Calanus helgolandicus and Centropages typicus according to the relevant reference (Bamstedt et al. 2000). Copepod clearance rates on ciliates were calculated according to Frost equations (Frost 1972). Ingestion rates were calculated by multiplying clearance rates by the initial standing stocks (Bamstedt et al. 2000). Egg production rates of the dominant calanoid copepods were determined by incubation of fertilised females (eggs/female/day) collected in the 0-100m layer. Copepod egg production was measured for the copepods Eucalanus monachus, Centropages typicus and Calanus helgolandicus. On board experiments for the estimation of copepod egg production were taken place. For the estimation of copepod production (mg/m**2/day), lengths (copepods and eggs) were converted to body carbon (Hopcroft et al., 1998) and production was estimated from biomass and weight-specific egg production rates, by assuming that those rates are representative for juvenile specific growth rates (Berggreen et al., 1988).

Effects of ocean acidification on the photosynthetic performance, carbonic anhydrase activity and growth of the giant kelp Macrocystis pyrifera

Under ocean acidification (OA), the 200 % increase in CO2(aq) and the reduction of pH by 0.3-0.4 units are predicted to affect the carbon physiology and growth of macroalgae. Here we examined how the physiology of the giant kelp Macrocystis pyrifera is affected by elevated pCO2/low pH. Growth and photosynthetic rates, external and internal carbonic anhydrase (CA) activity, HCO3 (-) versus CO2 use were determined over a 7-day incubation at ambient pCO2 400 µatm/pH 8.00 and a future OA treatment of pCO2 1200 µatm/pH 7.59. Neither the photosynthetic nor growth rates were changed by elevated CO2 supply in the OA treatment. These results were explained by the greater use of HCO3 (-) compared to CO2 as an inorganic carbon (Ci) source to support photosynthesis. Macrocystis is a mixed HCO3 (-) and CO2 user that exhibits two effective mechanisms for HCO3 (-) utilization; as predicted for species that possess carbon-concentrating mechanisms (CCMs), photosynthesis was not substantially affected by elevated pCO2. The internal CA activity was also unaffected by OA, and it remained high and active throughout the experiment; this suggests that HCO3 (-) uptake via an anion exchange protein was not affected by OA. Our results suggest that photosynthetic Ci uptake and growth of Macrocystis will not be affected by elevated pCO2/low pH predicted for the future, but the combined effects with other environmental factors like temperature and nutrient availability could change the physiological response of Macrocystis to OA. Therefore, further studies will be important to elucidate how this species might respond to the global environmental change predicted for the ocean.

Growth rates and possible age of a North Pacific manganese nodule

The rate of accumulation of a ferromanganese coating on a fragment of pillow basalt was estimated using a variety of techniques. Unsupported 230 Th activity decrease in the oxide layer, K/A dating of the basalt, fission tracks dating of the glassy layer around the basalt, thickness of the palagonitization rind, and integrated 230 Th activity give ages from approximately 3 x 10-6 years to 5 x 10-3 years. Data suggest that the ferromanganese material formed rapidly (33 mm/10-6 years) and by hydrothermal or volcanic processes.