Description: Es wird eine Methode zur Bestimmung des Kaloriengehaltes von partikularer Substanz aus Schöpfer- und Sinkstoffproben beschrieben. Die Proben werden auf Glasfaserfilter (Whatman GF/C, 2,25 cm Durchmesser) oder Membranfilter (Sartorius, Typ SM 1130, 2,5 cm Durchmesser) filtriert. Die Glasfaserfilter mit dem Filterrückstand werden nach Zugabe von Benzoesäure, die in Äthylalkohol gelöst ist, getrocknet und in einem Phillipson-Mikrokalorimeter verbrannt. Bei der Verbrennung der Membranfilter entfällt die Zugabe von Benzoesäure, da die Filter aus explosivem Cellulosenitrat bestehen. Sie können direkt nach der Trocknung verbrannt werden. Der methodische Fehler liegt bei der Verwendung von Glasfaserfiltern bei 27,1% und bei der Verwendung von Membranfiltern bei 9,6%. Als optimal erwies sich die Verwendung von Membranfiltern der PorengroBe 0,8 µ und die zweimalige Spülung des angereicherten Sestons auf dem Filter mit 2 bis 5 ml destilliertem Wasser. Die Glasfaser- und die Membranfilter weisen keinen signifikanten Unterschied in Bezug auf den Kaloriengehalt des abfiltrierten Sestons auf. In Bezug auf den Sestongehalt (als Trockengewicht) zeigt der Glasfaserfilter eine signifikant höhere Retention gegenüber dem Membranfilter (p1 〈 2% und p2 〈 0,1%). Es ergab sich ein signifikanter Unterschied (p 〈 0,2% in Bezug auf den Seston- und p 〈 0,1 % in Bezug auf den Kaloriengehalt) in der Retention der Filter bezogen auf 1 l Wasser bei der Filtration unterschiedlicher Wassermengen (1 l und 2 l). Aus diesem Grunde sollte immer die gleiche Menge Wasser zur Filtration verwendet werden. Der kalorische Aspekt der Phytoplanktonblüte im Frühjahr 1972 vor Boknis Eck wird dargestellt und diskutiert. Der Kaloriengehalt einer Phytoplanktonpopulation kann als Index für deren physiologischen Zustand angesehen werden.

Description: The energy flow of the pelagic part of a shallow water ecosystem is quantified using measurements of global incident radiation, particulate organic carbon, caloric content of the particulate matter, data from other authors on primary production, zooplankton secondary net production and zooplankton tertiary net production as well as several conversion factors from the literature. - The total potential radiant energy in 1973 amounted to 3.46 · 105 kcal m-2 y-1, the phytoplankton net production to 2.66 · 103 kcal m-2 y-1, with an average transfer efficiency of 0.77%. The zooplankton secondary and tertiary net production were 3.58 · 102 and 5.49 · 101 kcal m-2 y-1 respectively. More than 40% of the phytoplankton net production (1.08 · 103 kcal m-2 y-1) was remineralised within the water column, 35% of the phytoplankton net production (9.25 · 102 kcal m-2 y-1) sedimented directly to the bottom. The total transfer to the sediment amounted to 1.55 · 103 kcal m-2 y-1 (corresponding to 58.3% of the phytoplankton primary production), the further transfer to higher trophic levels was 4.34 · 101 kcal m-2 y-1 or 1.6% of the phytoplankton primary production.

Description: During the Second German Antarctic Expedition 24 stations were visited from Januarv to February 1978 between Bellinghausen Sea and South Georgia. Samples were taken for the determination of phytoplankton composition and biomass as well as for protozooplankton biomass. Primary productivity was measured as 14C-uptake for different size classes of the phytoplankton population (〈 20, 20-100 and 100-300 μm). Remarkable was the distribution of biomass and primary production within the different phytoplankton size classes. At nearly all stations the major part of the, biomass consisted of nanoplankton forms smaller than 20 μm which were responsible for about 90 % of the production. These tiny organisms were either diatoms (centric or pennate forms), μ-flagellates or dinoflagellates, thus representing the main phytoplankton groups. Protozooplankton cells were found at all stations, their biomass averaged about 16% of the phytoplanktion biomass. The obvious importance of nanoplankton forms as a food supplier for the krill (Euphausia superba) as well as the importance of protozooplankton as a food source and a food competitor for the krill during the Australian autumn are discussed.

Description: Results obtained from short-term (8 h to 24 h intervals) measurements of physical, chemical and biological properties of the 70 m water column from an anchor station in the Bornholm Sea over a 10-day period are presented and discussed. Phytoplankton biomass concentration and production rates indicated that the spring bloom was in progress in this period. The onset of the spring bloom occurred prior to the advent of thermal stratification. Peak growth rates, accompanied by nutrient depletion and biomass accumulation in surface layers, were concomitant with calm weather and a cloudless sky after which a part of the population was observed to sink out of the water column unimpeded by the permanent halocline. Maximum sinking rates of the dominant species, Skeletonema costatum, ranged between 30 to 50 m per day during this event. The development of the spring bloom apparently takes place in a series of events during which periods of low production alternate with periods of high production and rapid sedimentation of parts of the population.