Vertical Migration of Aquatic Animals

Diel vertical migration involves vertical migration over the 24 h day. The three patterns are nocturnal, twilight, and reverse, and they function as strategis for feeding and predator avoidance. Zooplankton either follow a preferred light level during migration or are cued to migration by the rate and direction of change in light at twilight. During selective tidal-stream transport, animals migrate vertically relative to tides. During flood-tide transport, animals move up estuaries by swimming in the water column during flood tide and descending to the bottom during ebb tides. The opposite occurs during ebb tide transport. The underlying mechanisms are tidal activity rhythms and responses to environmental factors.

Duke Scholars

Author Richard B. Forward Marine Science and Conservation