Meeting Abstract
67.9 Wednesday, Jan. 6 Population structure of a snail caught in a matrix of culture, economics, and political geography MEYER, Erin; Univ. of California, Berkeley emeyer@berkeley.edu
The intertidal habitat is frequently overlooked in both terrestrial and marine conservation. In the West Indies, there are several hundred protected areas, but none of them extend into the intertidal. Cittarium pica is the largest rocky intertidal gastropod and has a geographic range restricted to islands of the West Indies, with an irregular distribution in the southern Caribbean. Since the region was first colonized, humans have harvested this long-lived snail as not only a food resource, but also as bait, tools, and ornamental shells. Because of its life history and the recent increase in fishing pressure on the species, C. pica is of growing concern to fisheries managers in the region. Although, it is currently included in a few management plans (e.g. Guadeloupe, Puerto Rico, Turks and Caicos Islands, U.S. Virgin Islands), there are no empirical data on the fishery. This study assesses 1) the level of fishing pressure in 13 island groups in the West Indies and 2) the effect of human demographic, social and economic factors on size structure of C. pica populations. These data combined with ongoing studies of population genetic structure and habitat preferences are vital to informing conservation and management decisions. Over three field seasons, I have traveled to 22 islands in 13 island groups, where I collected data on the size structure at 42 different sites, including five sites in Bermuda where C. pica is fully-protected. The largest size classes (≥70mm) were uniformly missing within all island groups, except for the Turks and Caicos Islands, the Bahamas, and Bermuda – the only location where individuals greater than 100mm were found. Preliminary results are thus far consistent with the hypothesis that human population density, socio-economic factors, and enforced fishing regulations may help to explain the presence or absence of the larger size classes.
