ALBERT

Description: Experiments were conducted from 4 June to September 2007 inside laboratory facilities at the south coast of Madeira (32°38'N, 16°54'W). The organisms used for this study were the sea urchin Paracentrotus lividus collected at Doca do Cavacas (32° 38'06 N; 16° 56'52 W), the red seaweed Grateloupia imbricata collected from the marina of Funchal (32° 38'41 N; 16° 54'46 W) at 0.5 m water depth, and the brown seaweed Stypopodium zonale collected from boulders at Reis Magos, Caniço (32° 83'45 N; 16° 49'25 W) in water depths of 3-7 m. The study consisted of three sequential stages: (i) assessing algal light compensation points, (ii) inducing light limitation and grazing, (iii) assessing grazer consumption rates in no-choice feeding assays after light limitation and grazer impact. For the latter we used the algal material from stage (ii) (see additional file 1). Pilot studies were carried out in June 2007 to identify the Light Compensation Point (LCP) for both algal species, i.e. the light intensity at which the rate of photosynthesis (measured as oxygen production) equals respiration. For this, we reduced the amount of incoming light by placing various layers of black plastic gauze material with a mesh size of 1 mm on top of each aquarium. For both macroalgae, we had a total of 12 aquaria (3.5 L each) of with each was loaded with 30 - 40 g wet weight of seaweed material. We randomly assigned two aquaria to each of six different light regimes. The number of gauze layers used was 0, 1, 2, 3, 4 and 5. After we recorded the concentration of dissolved oxygen with an oxymeter (Oxi 197, WTW Wissenschaftlich-Technische Werkstätten GmbH, Weilheim, Germany) twice a day (9am and 5pm) for the following 4 days (see additional file 2). Experiments were carried out in July 2007 for G. imbricata, and in September 2007 for S. zonale. We conducted a two-factorial experiment for each of the species in which we crossed two levels of grazing ("grazed" and "non-grazed") with six levels of light intensities (0-5 layers of gauze material) and each treatment combination was replicated eight times (n=8). Consequently, we had 6 x 8 = 48 aquaria of which each contained one sea urchin, while another 48 aquaria had no sea urchins. The latter were used to determine total algal growth rates under the different light regimes in the absence of grazers and to provide non-grazed algal material for the feeding assays. In total we had 96 aquaria for each of the two seaweed species in the study and the respective treatments, i.e. light limitation and grazing, were imposed simultaneously for 21 days. We tested for possible effects of the previously applied light limitation and grazing (see stage (ii)) on grazer consumption rates in no-choice feeding assays that lasted for 24 h. Hence, the number of replicates for the assays at stage (iii) was the same as at stage (ii). Grazer consumption rates of algal material were determined as the grazers' total consumption, which was calculated using the equation suggested by Cronin and Hay (1996-a): [Ai x (Cf / Ci) - Af ] where Ai and Af were the initial and final weight of the algae portions used in the feeding assays; Ci and Cf are the equivalent weights of the growth control algal pieces before and after the assays (Sotka et al., 2002). Finally, consumption rates were standardised for grazer wet biomass (g alga/g grazer). Negative consumption was recorded in case algal growth rates during the assays exceeded consumption rates (see additional file 3 raw data).

Description: A systematic investigation of the extant coccolithophore community around Azores Archipelago was performed during the cruise M150 of FS Meteor between August, 27, and October, 2, 2018, in the scope of the project BIODIAZ - Controls in benthic and pelagic BIODIversity of the AZores. For the description of the spacial and vertical distribution of the extant coccolithophore community sampling was done at 50 stations along 9 transects including 3 islands, a seamount and islets from 5 to 8 water depths between surface and 150 m. A total of 306 samples were obtained, filtered onboard onto polycarbonate membranes and sections of these filters mounted in the laboratory on microscope slides for analysis by cross-polarized light microscopy. At least 400 coccospheres were counted through a randomly selected sequence of fields of view and the absolute abundances (Coccospheres/L) were estimated.

Description: Salinity and Oxygen were not calibrated beyond the manufacturer's calibration coefficients. Compared to climatological values (WOA18) salinity appears to be 0.05 PSU too low. Both CTD sensors and the two TSG sensors do however agree. Oxygen values are in the range of the climatological values, possibly 5 umol/kg too low. Some deep profiles show consistently low oxygen values that is not represented in the climatology. Use this data with caution.

Description: A systematic investigation of the extant coccolithophore community around Cabo Verde Archipelago was performed during the cruise MSM49 of FS Maria S. Merian between November, 28, and December, 21, 2015, in the scope of the project SEAMOX - Influence of Seamounts and Oxygen Minimum on Pelagic Fauna in the Eastern Tropical Atlantic. For the description of the spacial and vertical distribution of the extant coccolithophore community sampling was done at 10 stations to the north, east and south of Cabo Verde archipelago from 6 to 9 water depths between surface and 150 m. A total of 79 samples were obtained, filtered onboard onto polycarbonate membranes and sections of these filters mounted in the laboratory on microscope slides for analysis by cross-polarized light microscopy. At least 400 coccospheres were counted through a randomly selected sequence of fields of view and the absolute abundances (Coccospheres/L) were estimated.

Description: This paper presents new data sets relating to the abundance of atomic oxygen in the upper mesosphere and lower thermosphere, which were derived from the nighttime green line emission measurements of the SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY) instrument on the European Environmental Satellite (Envisat). These are compared to recently published data sets from the same SCIAMACHY green line measurements through the application of a different photochemical model and to data collected by the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument. We find that the retrieved atomic oxygen concentration depends on the choice of the underlying photochemical model. These dependencies explain a large proportion of the differences between recently published data sets. The impact of the 11-year solar cycle on volume emission rates and atomic oxygen abundances was analyzed for various data sets, with the finding that the solar cycle effect varies with the atomic oxygen data set used. The solar cycle impact on the SCIAMACHY data increases with altitude. Above 96 km, it is significantly larger than predicted by HAMMONIA (Hamburg Model of the Neutral and Ionized Atmosphere). Investigations indicate that these variations are primarily driven by total density compression/expansion variations during the solar cycle, rather than different photolysis rates.