Preliminary Measurements of Midsummer Metabolism in Beds of Eelgrass, Zostera Marina

Measurement of community metabolism in a coastal pond eelgrass bed gave values of 2.9 g O2 m—2 day —1 for apparent production and 3.6 g O2 m—2 day—1 for night respiration. The excess of consumption over production during a full day in early August is indicative of the declining state of the plants by midsummer. Measurements of upstream—downstream dissolved oxygen in a tidal river eelgrass bed showed unusual transients and occasional high values for production and respiration. These observations may have been related to turbulent tidal transport, to exchanges of oxygen between the water and lacunar spaces within the Zostera, and to higher metabolic rates in faster currents. See full-text article at JSTOR