The vertical profiles of phosphate, total CO2 and oxygen/hydrogen sulphide were
determined in the deep water of the Gotland Sea during March 2003 to July 2006
with a temporal resolution of 2–3 months. This time span included the shift
from anoxic to oxic conditions resulting from a water renewal event, as well as
the transition back to anoxic waters during the subsequent two-year stagnation
period. The data from depths below 150 m were used to identify and quantify
phosphate release and removal processes. The relationship between the total CO2
generated by mineralization (CT1 min) and the PO4 concentrations indicated that
the initial decrease in the phosphate concentrations after the inflow of oxygen-rich
water was mainly a dilution effect. Only about one third of the PO4 removal was
a consequence of the precipitation of insoluble iron-3-hydroxo-phosphates (Fe-P),
which occurred slowly at the sediment surface under oxic conditions. From the
CT1 min/PO4 ratios it was also concluded that the formation of Fe-P was reversed
during the later phase of the stagnation, when the redoxcline approached a depth
of 150 m. A phosphate mass balance was performed for four deep water sub-layers
in order to quantify the dissolution of Fe-P during the stagnation period and thus to estimate the amount of Fe-P deposited during the last inflow of oxygen-rich
water. A value of about 50 mmol-P m−2 was found, which refers to the specific
biogeochemical conditions during the change from anoxic to oxic conditions that
preceded the stagnation period.
Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies
Informacja
SZANOWNI CZYTELNICY!
UPRZEJMIE INFORMUJEMY, ŻE BIBLIOTEKA FUNKCJONUJE W NASTĘPUJĄCYCH GODZINACH:
Wypożyczalnia i Czytelnia Główna: poniedziałek – piątek od 9.00 do 19.00