Home range size and patterns of space use by lingcod, copper rockfish and quillback rockfish in relation to diel and tidal cycles

The estimation of home range size of marine fish has received attention because of its application to the design of marine reserves. How individuals use space may also be important to the management of the species and for understanding behavioral processes like optimal foraging or territoriality. We used an acoustic tracking system (VRAP) to examine patterns in home range size and movement behavior for 3 demersal fishes in Puget Sound: lingcod Ophiodon elongatus, copper rockfish Sebastes caurinus and quillback rockfish S. maliger. Data were collected over 8 wk in the summer of 2006 and 3 wk in the winter of 2007. Home ranges were relatively small (similar to 1500 to 2500 m(2)) and did not differ among species. During the summer, lingcod had larger home ranges during the clay than at night. Movement in all 3 species was in some way related to diel and tidal cycles, although individuals within species differed, and there was no general pattern. About half of the lingcod used portions of their home ranges only during the day and on the flood tide. Other individuals made similar movements on the ebb tide. Some copper rockfish moved to specific areas of their home range on the day ebb tide, while others made these movements on the night flood tide; others showed no pattern. Similar results were seen for quillback rockfish. While the arena of resource management often requires us to simplify complex systems, our results illustrate that such simplification may be difficult, and will depend ultimately on detailed behavioral data.