PARENT SESSION
Poster Session # 17: Aquatic Systems.

Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Connecting multi-scale movement patterns to population dynamics in a stream fish, Cottus bairdi.

Lamphere, Bradley^*,1, ¹ University of North Carolina - Chapel Hill, Chapel Hill, NC

ABSTRACT- Long moves, which represent the tails of a movement distribution, have great impact on population dynamics. Unfortunately, the infrequency of long moves makes them difficult to observe in the field for most species. As a result, to study the extent of and cues to movement, I selected a stream fish noted for its sedentary habits, the mottled sculpin, Cottus bairdi. If movement beyond normal home range is significant and scale-dependent in C. bairdi, it likely is for more vagile species as well. Over 43% of individually-marked recaptures moved 20 m or more. Moreover, the proximal cues to reach-scale moves (20 − 180 m) differed from shorter moves, particularly during the spring breeding season. While moves during summer exhibited the negative density dependence expected of a territorial species, moves which occurred in the spring showed the opposite trend (i.e., conspecific attraction). Next, I manipulated C. bairdi density and breeding habitat availability during summer and spring to determine whether the conspecific attraction was (1) a direct response to C. bairdi being present, or (2) an indirect result of C. bairdi being attracted to breeding habitat. In the absence of direct information on true dispersal events, ecologists often use extrapolations from mark-recapture data to estimate the shape of the movement distribution′s tail. Alternatively,genetic data can provide a more realistic estimate of the tail′s shape, beyond the range of traditional mark-recapture. I plan to use microsatellite DNA loci to (1) infer dispersal extent in this population and (2) make quantitative comparisons between the genetic data and several new and existing models for extrapolating mark-recapture data. Together, the mark-recapture, experimental, and genetic data indicate that even an exceptionally sedentary fish can exhibit complex and scale-dependent movement patterns at several levels. These results will directly aid efforts to use C. bairdi in biomonitoring and more generally enhance our understanding of the proximal causes and population-level consequences of movement.

Key words: mark-recapture, movement cues, Cottus, genetic