Meeting Abstract

P2.133  Wednesday, Jan. 5  Using mark-recapture to study the population biology of a non-native aquatic invader MCCANN, M.J.; Stony Brook University mccann@life.bio.sunysb.edu

The Chinese mystery snail Bellamya chinensis is native to Southeast Asia and was introduced to live food markets in San Francisco in the 1890s. It has spread to almost 30 states in the US primarily through the pet and aquarium trade. This species is unusual in that it produces live young, lives multiple years, and is much larger than native, freshwater snails. In the past century, there has been a handful of surveys of the presence or local density of B. chinensis in lakes, and few experimental studies of the community impacts of this non-native snail. Surprisingly, there has been a shortage of studies of its population biology, including estimates of its total abundance in a waterbody. Mark-recapture studies can be an effective means to elucidate many aspects of the life history of a species, including estimates of population size, survival, and capture probability. I used a population of B. chinensis, in a small (~2.4 hectares), shallow, eutrophic pond to test whether mark-recapture could be used to effectively study this species. From April to August 2010, 364 individuals were captured and marked, and 19% of those were recaptured at least once. Larger individuals were recaptured more often. No individuals <34 mm shell length were recaptured. Juvenile snails were first captured in late May and continued to be captured into late August. A Lincoln-Peterson, closed-population model was used to estimate population size. A Cormack Jolly-Seber, open-population model was used to estimate a time-invariant survival probability. Both models were solved via Markov Chain Monte Carlo sampling with MATLAB and Program MARK. Mark-recapture can be a useful tool for understanding the population dynamics and establishment of other aquatic invaders that are long-lived and large bodied like B. chinensis.