D2 tidal currents. Most of the sediment remains near the bed after it is suspended, so that it resettles to the bed during periods of weak currents. Near-bed salinity increases strongly at the end of the period, toward the neap tide. The D2 salinity variability is weak during the spring tide despite strong currents, probably because of reduced salinity stratification. Strong D3 and D4 variability reflect the influence of the greater ebb, which removes salt from the whole water column once per day.
Stability goes to zero on every greater ebb as salt is washed out of the system.
It provides in the figure below, an important hint regarding ecosystem function. The regularity of the attached bacterial productivity is remarkable for a biological variable. Thanks to Byron Crump and John Baross University of Washington, School of Oceanography for the microbial productivity data.