In zone 2, the surface of the creek bed is free of mud,
and algae is rare. At low tide, the water is warm, placid and shallow
(under 10 cm depth). The substrate is composed mainly of pebbles,
about 2-5 cm in diameter, which are covered by a fine green algal film.
This is the first appearance of large masses of chitons that--along with
limpets, oysters, and Hemigraspus crabs--are predominant large fauna.
The oysters are generally much smaller (7 cm), than in zone 1 and are arranged
in beds that parallel the stream. Oyster density varies from bed to bed
and some sharp demarcations between oyster beds and oysterless areas are
found, as well as dense beds drifting into sparsely scattered oysters.
The water is clear and shallow, making this is a great zone to just sit
and watch the activity: brachyuran crabs scuttling, hermit crabs fighting
over new shells, whelks and limpets moving, the serpulid worms suspension
feeding with their red fanned tentacles, sculpins darting around.
Under the top layer of rocks, many little Balanus barnacles, bryozoans,
green anemones, and in some places subtidal sponges (Haliclona)
are found under only centimeters of water. The sediment gets muddy and
sandy as one digs deeper. Here one finds terebellid polychaetes,
littleneck clams of varying sizes, tiny white brittle stars, and high spired
gastropods.
