(Table 2) Biomass and size characteristics of Aurelia aurita in the Black Sea as determined from the Argus manned submersible

Based on estimate of Aurelia aurita concentration in the Black Sea from the Argus manned submersible in April-May 1984, as well as on author's data and published information on metabolic rate and feeding of medusa, biomass of medusa Aurelia aurita in the epipelagic zone of the Black Sea is estimated to be about 400 million tons of wet weight, and its mean annual production to be 400-900 million tons wet weight or about 1.1-2.5 million tons of organic carbon, equivalent to approximately 1-3% of primary production.

Export of algal biomass from the melting Arctic sea ice

In the Arctic, under-ice primary production is limited to summer months and is not only restricted by ice thickness and snow cover but also by the stratification of the water column, which constrains nutrient supply for algal growth. RV Polarstern visited the ice-covered Eastern Central basins between 82 to 89°N and 30 to 130°E in summer 2012 when Arctic sea ice declined to a record minimum. During this cruise, we observed a widespread deposition of ice algal biomass of on average 9 g C per m**2 to the deep-sea floor of the Central Arctic basins. Data from this cruise will contribute to assessing the impact of current climate change on Arctic productivity, biodiversity, and ecological function.

Biomass of the main elements of the planktonic community in the Equatorial Pacific upwelling

Based on samples with a 140-liter bottles in the upwelling region of the equatorial Pacific, an analysis was made of vertical distribution of various members of the plankton community of organisms (small and large phytoplankton, bacteria, different groups of protozoans, small and large, mainly herbivorous and predatory, animals). There is a distinct vertical divergence between layers of dominance of groups with similar feeding habits against the background of uneven quantitative distribution. Contrariwise, there are masses of consumers in the layers of high concentration of their potential prey.

Ichthyoplankton density and zooplankton biomass in the Benguela upwelling system during MSM17/3 in January and February 2011

Ichthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in January/February 2011 were determined for 38 stations in the northern Benguela upwelling system, based on oblique Multinet hauls during the FS Maria S. Merian MSM17/3 cruise. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 38 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. In addition, densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta (depth bot[m]-depth top [m]).

Ichthyoplankton density and zooplankton biomass in the Benguela upwelling system during MSM19/1b in October 2011

Ichthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in October 2011 were determined for 22 stations in the northern Benguela upwelling system, based on oblique Multinet hauls during the FS Maria S. Merian MSM19/1b cruise. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 22 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. In addition, densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta (depth bot[m]-depth top [m]).

(Table 1) Biomass per area of picoplankton algae, cyanobacteria, and total picoplankton and their contribution to total phytoplankton biomass in 0-200 m layer

Abundance of picophytoplankton in the Subantarctic and subtropical frontal zones was found to be 10**6-10**7 cells/l. Biomass of eucaryotes and procaryotes reached 2 g/m**2 and accounted for 1-15% of total phytoplankton biomass. A deep peak in the distribution of phytoplankton abundance was found at 40-120 m. Maximum number of dividing cyanobacteria cells occurred at depths of 40-60 m. An estimate of picophytoplankton production shows that picophytoplankton accounts for 30-40% of total primary production.

Jelly biomass sinking speed reveals a fast carbon export mechanism

Particulate matter export fuels benthic ecosystems in continental margins and the deep sea, removing carbon from the upper ocean. Gelatinous zooplankton biomass provides a fast carbon vector that has been poorly studied. Observational data of a large-scale benthic trawling survey from 1994 to 2005 provided a unique opportunity to quantify jelly-carbon along an entire continental margin in the Mediterranean Sea and to assess potential links with biological and physical variables. Biomass depositions were sampled in shelves, slopes and canyons with peaks above 1000 carcasses per trawl, translating to standing stock values between 0.3 and 1.4 mg C m2 after trawling and integrating between 30,000 and 175,000 m2 of seabed. The benthopelagic jelly-carbon spatial distribution from the shelf to the canyons may be explained by atmospheric forcing related with NAO events and dense shelf water cascading, which are both known from the open Mediterranean. Over the decadal scale, we show that the jelly-carbon depositions temporal variability paralleled hydroclimate modifications, and that the enhanced jelly-carbon deposits are connected to a temperature-driven system where chlorophyll plays a minor role. Our results highlight the importance of gelatinous groups as indicators of large-scale ecosystem change, where jelly-carbon depositions play an important role in carbon and energy transport to benthic systems.

Ichthyoplankton density and zooplankton biomass in the northern Benguela upwelling system during D356 September 2010

Ichthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in September 2010 were determined for 10 stations in the northern Benguela upwelling system, based on oblique Multinet hauls during the RRS Discovery D356 cruise. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 10 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. In addition, densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta(depth bot[m]-depth top [m]).

Ichthyoplankton density and zooplankton biomass in the Benguela upwelling system during AFR258 in December 2009

IIchthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in December 2009 were determined for 22 stations in the Benguela upwelling system, based on oblique Multinet hauls during the FRS Africana cruise AFR258. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 22 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. Densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta (depth bot[m]-depth top [m]).

Ichthyoplankton density and zooplankton biomass in the Benguela upwelling system during MSM07/3 in March 2008

Ichthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in March 2008 were determined for 32 stations in the northern Benguela upwelling system, based on oblique Multinet hauls during the FS Maria S. Merian MSM07/3 cruise. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 32 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. In addition, densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta (depth bot[m]-depth top [m]).

Ichthyoplankton density and zooplankton biomass in the Benguela upwelling system during MSM18/4 in July and August 2011

Ichthyoplankton density (fish eggs and larvae) and bulk zooplankton biomass in September 2010 were determined for 10 stations in the northern Benguela upwelling system, based on oblique Multinet hauls during the RRS Discovery D356 cruise. A HYDROBIOS Multinet, type Midi (0.25 m**2 mouth area) was equipped with five nets of 500 µm-mesh size, temperature and oxygen probes, and an inner and outer flow meter to monitor the net's trajectory (for volume filtered calculations) as well as net clogging. The Multinet was handled over the side, towed horizontally at 2 knots. Winch speed when fearing was 0.5 or 0.3 m/s, heaving velocity 0.2 - 0.3 m/s. The Multinet was towed obliquely at 10 stations sampling the upper 200 m of the water column, which were divided into five different depth strata after inspection of temperature and oxygen concentration depth profiles. Ichthyoplankton densities and zooplankton biomass were calculated for each depth stratum (=single net) from total abundance and the volume of water filtered [individuals per m**3 and g wet weight per m**3, respectively]. In addition, densities and biomass were integrated over the area for each station [individuals per m**2], as sum of calculations for each net: Sum ([individuals per m**3]*Delta(depth bot[m]-depth top [m]).

Table 1: Station list with macrobenthos biomass results from the ocean floor

Among the Siberian shelf seas the Kara Sea is most strongly influenced by riverine runoff with nearly 1500 km fresh water discharge per year. This fresh water, discharged mainly by Ob and Yenisei, contains about 3.1 * 106 and 4.6 * 106 tons of total organic carbon per year, respectively (Gordeev et al. 1996). Little is known about the relevance of this organic material for biological communities, neither for the Kara Sea nor for the adjacent deep basins of the central Arctic Ocean. Aiming at elucidating the fate of fluvial matter transported from the rivers via estuaries into the central Arctic Ocean and the relative importance of marine organic matter being produced such information is crucial. Here we present calculations on the organic carbon demand of the Kara Sea macrozoobenthos based on measured biomass (total wet weight [ww] per 0.25 m ) from quantitative box corer samples and empirical relationships between biomass, annual production, annual respiration, and carbon remineralisation. This bottom-up approach may serve as a first estimate of the carbon remineralization potential of a given zoobenthos community (or area) as long as no data on in situ respiration rates are available. Our data basis comprises 54 stations sampled in summer seasons 1997, 1999 and 2000 in the Kara Sea at water depths between 10 and 68 m. The geographical area represented by stations analysed covers roughly 178 000 km**2, which is about one fifth of the total Kara Sea area. In this area, 290 species of invertebrate macrozoobenthos were identified with polychaeta, Crustacea, mollusca and echinodermata being the most abundant. For all stations analysed, mean biomass values ranged between 4.3 and 778.1 g ww/m**2 with organic carbon demands between 3.5 and 43.2 mg C/m**2/d. For the area of 178 000 km2 a preliminary total consumption of 1.4 * 10**6t Corg/y (equivalent to 21.5 mg C/m**2/d) was calculated for the macrozoobenthos. An extrapolation of our data would lead to an annual carbon demand of about 5-7 * 106 t for the whole Kara Sea macrozoobenthos (or 15.5-21.7 mg C/m2/d).

Benthos activity, abundance and biomass in surface sediments off Morocco, Northwest Africa

Macro- and meiobenthic abundance and biomass as well as metabolic activity (respiration, ETS activity) have been studied along a transect ranging from 130 to 3000 m water depth off northern Morocco (35° N) during "Meteor" cruise No. 53 (1980). The distribution of chloroplastic pigment concentration (chlorophyll a, pheophytins) in the sediment has been investigated as a measure of sedimented primary organic matter. High chloroplastic pigment concentrations were found on the shelf and around the shelf break, but values declined rapidly between 200 and 600 m depth. Below 1200 m pigment concentrations remained at a relatively uniform low level. Macrobenthic abundance and biomass (wet weight) decreased with increasing water depth and with distance from the shore. Significant changes occurred between the shelf and upper slope and below 2000 m depth. Meiobenthic abundance and biomass (ash free dry weight) followed the same general pattern, but changes were found below 400 and 800 m depth. In the depth range of 1200 to 3000 m values differ only slightly. Meiofauna abundance and biomass show a good correlation with the sedimentary chloroplastic pigment concentrations. Respiratory activity of sediment cores, measured by a shipboard technique at ambient temperatures, decreased with water depth and shows a good correlation with the pigment concentrations. ETS activity was highest on the shelf and decreased with water depth, with significant changes between 200 and 400 m, and below 1200 m depth, respectively. Activity was generally highest in the top 5 cm of the sediment and was measurable, at all stations, down to 15 cm sediment depth. Shelf and upper slope stations exhibited a vertical distribution pattern of ETS activity in the sediment column, different from that of deeper stations. The importance of biological activity measurements as an estimate of productivity is discussed. To prove the thesis that differences in benthic abundance, biomass and activity reflect differences in pelagic surface primary production, in the case of the NW-African coast caused by different upwelling intensities, the values from 35° N were compared with data from 21° N (permanent upwelling activity) and 17° N (ca. 9 months upwelling per year). On the shelf and upper slope (< 500 m) hydrographical conditions (currents, internal waves) influence the deposition of organic matter and cause a biomass minimum between 200 and 400 m depth in some regions. But, in general, macrobenthic abundance and biomass increases with enhanced upwelling activity and reaches a maximum in the area off Cape Blanc (21° N). On the shelf and in the shelf break region meiofauna densities are higher at 35° N in comparison to 21° N; but in contrast to the decreasing meiofauna abundance with increasing water depth at 35° N, an abundance maximum between 400 and 1200 m depth is formed in the Cape Blanc region; this maximum coincides with the maximum of sedimentary chloroplastic pigment equivalents. The comparison of ETS activities between 35° N and 21° N shows on the shelf activity at 21° N is up to 14 times higher and on the slope 4-9 times higher, which demonstrates that benthic activity responds to the surface productivity regime.