Inter-Stream Movements and Seasonal Activity of Two Large Galaxiids within a Small Stream System
Cindy F. Baker and Joshua P. Smith
Abstract.—The extent of intra- and inter-stream movements of two large galaxiids, banded kokopu Galaxias fasciatus and giant kokopu Galaxias argenteus, were monitored using a passive integrated transponder (PIT) tag system. In total, 103 banded kokopu and 51 giant kokopu were tagged in three small lowland streams. Within one stream, stationary recording antennae were installed at six locations, and fish movements were monitored for two years. Site fidelity was seen in less than 20% of both kokopu species, with around 40% of both banded and giant kokopu found to frequently undertake intra-stream movements to new cover locations. Movements ranged up to 1000 m for both species with seasonal patterns exhibited. In addition to local movements, inter-stream movements were also recorded in approximately 25% of giant kokopu and 5% of banded kokopu monitored. The extent of intra- and inter-stream movements exhibited by both species highlights the need to consider adult fish migrations in both stream restoration and fish passage design, to ensure upstream and downstream movements of adult galaxiids are unhindered.