MEPS 126:9-17 (1995)  -  doi:10.3354/meps126009

Use of rocky intertidal habitats by juvenile pollock Pollachius virens

Rangeley RW, Kramer DL

We investigated patterns of distribution and foraging by young-of-the-year pollock Pollachius virens in the rocky intertidal zone. Pollock were sampled by beach seine in fucoid macroalgae and in open habitats at all stages of the tide, day and night throughout the summer. Their presence in shallow water at the high tidal stages indicated that at least part of the pollock population migrated across the full width of the intertidal zone (150 m) each tide. Densities in shallow water were much higher at low than at high tidal stages suggesting that a large influx of pollock moved in from the subtidal zone at low tidal stages and then dispersed into intertidal habitats at high tidal stages. There were few differences in pollock densities between algal and open habitats but abundances likely increased in the algal habitat at higher tidal stages when changes in habitat availability are taken into account. Densities were higher at night and there was an order of magnitude decline in pollock densities from early to late summer. In another study we showed that piscivorous birds are a probable cause of pollock summer mortality. Pollock fed on invertebrates from intertidal algae relatively continuously. The tidal migrations of juvenile pollock observed in this study and their use of macroalgae as a foraging and possibly a refuging habitat strongly suggests that the rocky intertidal zone may be an important fish nursery area.

Marine fish nursery . Rocky intertidal zone . Habitat selection . Pollachius virens . Pollock . Macroalgae. Foraging . Gadidae . Beach seine

Full text in pdf format