J. Lehtoranta et al., SEDIMENT ACCUMULATION OF NUTRIENTS (N, P) IN THE EASTERN GULF-OF-FINLAND (BALTIC SEA), Water, air and soil pollution, 99(1-4), 1997, pp. 477-486
Dry weight (DW), ignition loss (IL) and concentrations of total nitrog
en (TN) and total phosphorus (TP) of the sediment surface layer (0 to
10 cm, 1 cm slices) were analyzed from 20 sites in the eastern Gulf of
Finland. The distance of the sampling sites from the mouth of the Riv
er Neva explained the nutrient concentrations of the sediments well, w
hile the effect of water depth was negligible. The increase of TN and
the decrease of TP along the transect from the river mouth towards the
open Gulf were caused by the diminishing share of allochthonous mater
ial supplied from the River Neva. The mean TN concentration of the dif
ferent accumulation areas was about 40 % higher in the sediment surfac
e than in the deeper layer (9 to 10 cm). The corresponding difference
for TP varied from 53 to 56 %. The results suggest considerable netflu
x of nutrients from sediment to water. The net sediment accumulation o
f nutrients were estimated as 6.0 g m(-2) a(-1) of N and 1.7 g m(-2) a
(-1) of P corresponding 22 000 t a(-1) of N and 6 100 t a(-1) of P for
the whole eastern Gulf.