Apparent Survival and Detection Estimates for PIT-Tagged Slimy Sculpin in Five Small New Brunswick Streams

Abstract

The slimy sculpin Cottus cognatus is an abundant and widespread benthic fish that inhabits cold lakes and rivers in North America. The objective of this study was to estimate survival and detection probabilities for slimy sculpin in relation to several environmental and biological predictors. Passive integrated transponder (PIT) tags were implanted into 337 adult slimy sculpin in five tributaries of the Kennebecasis River, New Brunswick, Canada. A portable PIT tag antenna was used to search for marked individuals from June 2003 to July 2004. Cormack–Jolly–Seber open population models were used to test several predictions and to estimate apparent survival and detection probabilities. We found that survival was high (73–99%) among sampling events; the average period was about 4 weeks (range, <1–22 weeks). Survival was positively related to fish length and negatively related to maximum stream discharge. The mean detection probability of tagged sculpin was 0.80, but it varied among sampling events and with respect to the minimum electrical current of our antenna and the percentage of boulder substrate at the site. This study demonstrates that a portable PIT tag system can be used in conjunction with capture–mark–recapture models to acquire an understanding of the basic life history characteristics of slimy sculpin and possibly other small-bodied fish in freshwater systems.