Abstract
Temporal and vertical variations of zooplankton at a station on the north-western Portuguese shelf, close to the Ria de Aveiro inlet, were
studied during two periods of 25 h each in the summer of 1994. Zooplankton sampling was carried out every 2 h, using horizontal plankton
tows (mesh size, 500 µm). Sampling was carried out in two depths, 4 and 12 m