|Biomassa en produktie van macro-algen|
Goedheer, P.F. (1977). Biomassa en produktie van macro-algen. Interne verslagen Nederlands Instituut voor Onderzoek der Zee, 1977(11). NIOZ: Texel. 52 pp.
Deel van: Interne verslagen Nederlands Instituut voor Onderzoek der Zee. Nederlands Insituut voor Onderzoek der Zee, meer
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Although data for primary production of phytoplankton and microphytobenthos in the Dutch Wadden Sea are available, macro- phytobenthos data are still lacking. Therefore field-observations of biomass and primary production were started in 1976 on different tidal stations near Texel. Biomass was estimated by sampling at regular intervals near fixed stations and by a "line-transect" method. Average biomass value for 37 stations in the Mokbaai during the top of the growing season was 11.2 g dry weight/m². Maximum observed values were 2.5 g, 23.3 g and 55.0 g dry weight/m² for respectively tube-dwelling diatoms, Enteromorpha and Ulva. Primary production was measured with the 14C method, it varied from 8.4-75.7 mgC/g dry weight/day. Biomass/m² and primary production/dry weight.day were used to calculate primary production/m² for the different days. Annual primary production of macroalgae amounts to 5-26 gC/m².year i.e. considerable lower than values observed both for phytoplankton and microphytobenthos in the Dutch Wadden Sea (about 100 gC/m².year). Transport of macroalgae from where they start growing plays an important role in the Wadden Sea. Some idea of its importance could be gained from the estimation of a "potential biomass" of macroalgae, using biomass at the beginning of the growing season and the measured primary production/dry weight during the season. This "potential biomass" was 1-100 times higher than the observed biomass. This indicates the importance of factors decreasing biomass of which transport will be the most important.