The latter discolours the sand and so one finds, round the coast and towards the upper margin of the zone between highand low-water marks, an under layer of black sand formed in this way.
The efforts of the river authorities are being directed to the deepening and improvement of the navigable channel from the sea to Strassburg, the low-water depths aimed at being TO ft.
Deep. In June 1908 the maximum low-water draft of the channel and the basin was 19 ft.
Above low-water mark, thus inundating the plains for many miles along both its banks.
Above low-water level, Paramaribo is well-drained, clean and in general healthy.
At low-water spring-tide on the bar.
The brightest belongs to those species which grow near low-water mark, or under the shade of larger algae at higher levels; species which grow near high-water mark are usually of so dark a hue that they are easily mistaken for brown seaweeds.
Of the edible river fish, the best known is the pirarucd (Sudis gigas), a large fish of the Amazon which is salted and dried for market during the low-water season.
They occur in mud and on sea-weeds at the bottom of shallow seas below low-water mark and devour organic debris.
This weir retains the river above it at half-tide level, in order to cover the mud-banks which had been bared at low tide between Richmond and Teddington by the lowering of the low-water level, owing to the removal of various obstructions in the river below.