Fish immigration/emigration and habitat use in the lower Hatzic watershed

The objective of this project was to obtain information on salmonid, white sturgeon and other species (natives and exotics) presence, habitat use, and migration success above and below the pumping station in the lower Hatzic watershed. Sampling was done in June (pumps operating) and August (pumps deactivated), but not in early spring (when pumps not operating) as FSWP funding was not approved until late May. An inventory was obtained of the numbers and sizes of fish caught by species during the two sampling periods. In June, the catch comprised juvenile salmonids (coho and steelhead), white sturgeon (size range 262-1120 mm FL) and several other native (sticklebacks, sculpins, suckers, pikeminnows, peamouth chub, redside shiners) and non-native (black crappie, pumpkinseed sunfish, carp) species. In August, no salmonids were captured, and the catch of white sturgeon (size range 329-402 mm FL) and other species (both natives and exotics) was reasonably similar to that sampled in June. No sturgeon were caught above the pumping station in either sampling period. Some differences occurred in the catch above and below the pumping station, but as the habitat of these areas differed appreciably and sampling was limited, it is not possible to discern what effects the pumping station has on fish movements. The three-spine stickleback was the most common native species, whereas pumpkinseed sunfish and black crappie were the most common non-native species in both sampling periods.