Description: With the increasing aging of an upwelling body of water, a pronounced rise in the saprophyte counts was found at first in the surface water and later also in the deeper zones. They increased, for example, at a depth of 15 meters, from 30-50 to 250 bacteria/ml, which represents a production of 4 X 10-3 mg bacterial C/m3 water. Different bacteria populations were included on the medium used for isolation, which was prepared with both sea-water and fresh water. On the former, which had relatively few species represented, the spectrum ranged from whitish to yellowish-white halophilic marine bacteria. On the tap water medium, however, dominated a spectrum of white or vividly pigmented bacteria, comprising many species, with maximal development in fresh water. It is supposed that bacteria of terrestrial origin are involved here, which are possibly carried to the sea by sand or dust storms. With regard to the colony forms, no difference between the bacteria populations within or without the upwelling water could be determined. The greatest bacterial infiltration of the sediment was found on the surface (between 16 X 103 and 80 X 103 bacteria/cm3). Already in the upper 2 cm, a strong reduction of the saprophyte count was determined, together with a relative increase of those bacteria which possess a greater range of ecological amplitude. The saprophyte counts on the sediment surface decreased with an increase of water depth. On 21 strains of bacteria isolated from the open waters, investigations were carried out on their morphological characteristics and the most important metabolic reactions.

Description: The test compound p-nitrophenol during summer normally is rapidly degraded in the freshwater area of the Elbe river. In contrast, degradation of PNP is decreased significantly during periods of low temperature or low oxygen content. Thus the xenobiotic compound is carried to the North Sea. In estuarine and marine environments the degradation of PNP is diminished step by step towards the open sea and is finally ceased completely, mostly as a result of increasing salinity.

Description: Between 28 August and 5 September 1982 thirty water samples (5 m depth) were taken on a transect between the Bothnian Bay and the Kiel Bight. Despite substantially differing hydrographical situations within the different subregions of the Baltic Sea, the total bacterial numbers showed a remarkable regional uniformity. Bacterial numbers fluctuated between 3 and 4 x 106 cells ml-1. A distinct pattern was observed: mean bacterial cell volumes were high in the Bothnian Bay (0.145 µm3) and low in the Gotland- and Bornholm Sea (0.094 and 0.091 µm3, respectively). The bacterial biomass fell in the range of 184 - 117 µg C 1-1. The activity parameters were somewhat more variable than bacterial numbers and biomass.

Description: An acclimated mixed culture of degrading bacteria and a degradable substance (4-Nitrophenol) were introduced into differently treated water samples. It could be shown that in all cases where an acclimated inoculum was used, degradation took place almost immediately compared to not acclimated cultures, where it took at least 10 days. The rate and extent of mineralization was influenced by low temperature, the presence of other organic nutrients and especially protozoan grazing. The data suggest that one of the main reasons for the acclimation period was the very small initial population of degrading bacteria. The role of other carbon sources is ambivalent. Low concentrations of organic chemicals which cannot sustain growth slow down acclimation and the degradation rate. Another important factor slowing down growth is grazing by protozoa, which can inhibit effective degradation.

Description: Ziel dieser Arbeit war es, einen Beitrag zur Klärung des Problems der Selbstreinigung von Gewässern unterschiedlichen Salzgehaltes zu liefern. An Hand verschiedener Parameter wurde in geeigneten Versuchsgefäßen der Abbau von häuslichem Abwasser in Süßwasser und in Ostseewasser verglichen, um festzustellen, wie sich der Salzgehalt auf die Dekomposition der Schmutzstoffe auswirkt. Es konnte festgestellt werden, daß dieser im Ostseewasser anfangs nicht langsamer verläuft als im Süßwasser. Erst nach 3-4 Tagen setzt eine Verzögerung ein, die sich vor allem in einer verlangsamten Nitrifikation bemerkbar macht und möglicherweise auf den im Brackwasser stärkeren Rückgang der Abwasser- und Süßwasserbakterien zurückzuführen ist. Die bakterizide Wirkung tritt anfangs infolge der hohen Nährstoffkonzentration zurück und macht sich erst nach einigen (1-3) Tagen bei Abnahme der Nährstoffe bemerkbar. In der Anfangsphase scheint sich der Salzgehalt des Ostseewassers in vitro eher günstig auf den Abbau auszuwirken, wobei vielleicht der höhere osmotische Wert eine Rolle spielt. Die Übertragung dieser in vitro gewonnenen Ergebnisse auf die natürlichen Verhältnisse ist zwar nicht ohne weiteres möglich bei Berücksichtigung der Ergebnisse von Standortuntersuchungen im Bereich der Abwassereinleitung der Stadt Kiel in die Ostsee bei Bülk ergibt sich jedoch, daß die Selbstreinigungskraft des Brackwassers so groß ist, daß es von Vorteil sein kann, Küstengewässer an Stelle von benachbarten Binnengewässern als Vorfluter zu verwenden.