Water current pervades every facet of existence for life in lotic (flowing water) habitats.
Maintaining position in the face of flow can be energetically costly but provides access
to a conveyer belt-like food-delivery system. Stream and river organisms reflect their
localized niche and surrounding landscape both upstream and downstream. River
organisms have evolved in diverse and fascinating ways in the varied environments
between river source and mouth.
Streams and Rivers: Habitats Partitioned at Different