In the 3 year period May 1975 - April 1978, monitoring of the particulate
oil pollution in the Skagerrak and the North Sea has been carried out, following
extensive base-line investigations in the first half of 1975. More
occasional observations have been made in the Barents Sea.
In the Skagerrak tar balls were present in more than half of the samples,
a decrease from three quarters during the base-line studies. Concentrations
have remained fairly constant, averaging about 0.2 mg/m2 sea surface.
In the North Sea tar balls were present in two thirds of the samples, an
increase from less than one half since the base-line work. Average concen-
trations have also increased from less than 0.1 to 0.2 mg/m2.
In the Barents Sea tar balls were present in one third of the samples, in
trace concentrations of less than 0.1 mg/m2.
These results may indicate a shift in the oil discharges from coastal
waters to the open sea. A breakdown of the oil particulates in the coastal
current enroute to the Barents Sea may also be apparent
