Fc. Vanduyl et Aj. Kop, BACTERIAL PRODUCTION IN NORTH-SEA SEDIMENTS - CLUES TO SEASONAL AND SPATIAL VARIATIONS, Marine Biology, 120(2), 1994, pp. 323-337
Benthic bacterial production and biomass were measured at 16 stations
in the North Sea covering a wide range of sediment types from the Sout
hern Bight and the English coast to the Skagerrak. Stations were sampl
ed in August 1991 and February 1992. The best predictor for summer/win
ter and spatial variations in benthic bacterial production in North Se
a sediments was temperature. In winter the ranges in temperature were
too small to account for the spatial variations in benthic bacterial p
roduction. The direct effect of temperature alone on bacterial product
ion could not explain the variations. The apparent Q(10)-values derive
d from the relations between bacterial growth and temperature exceeded
the range in Q(10)-values generally accepted for bacterial growth (be
tween 2 and 3). Temperature was assumed to covary closely with substra
te availability for bacteria. Due to its significant seasonality phyto
pigment content of the sediment (chlorophyll a and pheopigment) was fo
und to be a better indicator of substrate availability than sediment o
rganic matter, which did not demonstrate seasonality. Temperature and
phytopigment accounted for up to 88% of the seasonal and spatial varia
tions in bacterial production. The significant relations between bacte
rial production and biomass in summer coinciding with significant rela
tions between bacterial biomass and phytopigments suggest that variati
ons in phytopigments in the sediment may be indicators of the variabil
ity of labile components regulating bacterial production in sediments.