Particulate amino acids in Wadden Sea waters — seasonal and tidal variations

Particulate amino acids (THAA) were measured in the East Frisian Wadden Sea at monthly intervals from February to December 1995. Each time two tidal cycles were sampled at hourly intervals. THAA made up between 3 and 50% (mean 15±7%) of the particulate organic carbon and between 9.3 and 104% (mean 49±20%) of the total nitrogen pools. Seasonal variations of THAA followed the development of phytoplankton in the water column while tidal variability was controlled largely by physical forcing such as tidal current velocities and wave action. The overall molar composition of the THAA pool appears to be dominated by a detrital signal originating from erosion of surface sediments.