A COMPARISON OF THE MOVEMENTS OF 2 SPECIES OF GADOID IN THE VICINITY OF AN UNDERWATER REEF

Two saithe (35 and 38 cm) and two pollack (43 and 44 cm) were tracked simultaneously for 170 h. During the day, saithe generally patrolled o ver the whole of an underwater reef as part of a school, making occasi onal excursions off the reef to another smaller reef 250 m distant. At night, saithe movements were largely limited to the reef. Pollack cov ered less than 50% of the reef during the study period, moving only sm all distances off the reef. Pollack swam more slowly than saithe durin g the day, but at the same speed at night.