Über die Schwankungen der abiotischen Faktoren in der Elbmündung bei Cuxhaven
Kühl, H. (1964). Über die Schwankungen der abiotischen Faktoren in der Elbmündung bei Cuxhaven. Helgol. Wiss. Meeresunters. 10(1-4): 202-216
In: Helgoländer Wissenschaftliche Meeresuntersuchungen. Biologische Anstalt Helgoland: Hamburg. ISSN 0017-9957, more
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| Abstract |
On the fluctuations of abiotic factors in the Elbe estuary near Cuxhaven. The changes of abiotic factors, especially salinity, water temperature, O2-content, pH and alcalinity in the Elbe river near Cuxhaven are documented. Long-term salinity fluctuations depend on the water outflow of the Elbe. Short-term salinity changes are caused by the tides. During the period from 1949 to 1953 and again in 1959, salinity was high (above 20%o in summer). From 1954 to 1958, as well as in 1961, salinity was low, at times considerably below 15 %o. At high tide with its increasing salinity, plankton samples contain more copepods and larvae of balanids and spionids since the maximum population density of these forms occurs in the polyhalinicum at the light-ship "Elbe 3". If the conditions are favorable, the larvae can settle and start a new population. In a small locality near the "Alte Liebe" pier, marked off by two jetties, the salinity is always somewhat higher than it is in the river Elbe. In this higher salinity, populations of Coryne sarsi as well as young Asterias rubens were found in all years characterized by increased salinities (monthly average about 15 to 20 %n). In years with higher salinities Teredo navalis caused increased deterioration of timber work. Small water pools in the mud flat area showed profound changes in water temperature, salinity and pH. Their O2 content is very high due to the photosynthesis of diatoms, reaching saturation values of 320 %. These extremes disappear quickly as the water returns at high tide. |
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