Meeting Abstract

P1.13  Tuesday, Jan. 4  Effects of the invasive alga Gracilaria salicornia on coastal benthic molluscan species diversity in east Hawaii STROHL, Robert D; DEMAINTENON, Marta J*; Univ. of Hawaii, Hilo; Univ. of Hawaii, Hilo demainte@hawaii.edu

Mollusks comprise diverse taxa that provide crucial ecological links in coastal marine habitats. These organisms are highly sensitive to the environment around them and thus any changes can greatly affect molluscan species diversity. Gracilaria salicornia (C.Agardh) E.Y.Dawson, 1954 is an invasive alga species in Hawaii, which has become prevalent in many coastal marine ecosystems. Its interactions with native species are not well documented. In this study, we investigated the relationship between abundance of G. salicornia and benthic molluscan species abundance and diversity. Three levels of G. salicornia abundance (low, intermediate, high) were surveyed at two sites in Hilo, on Hawaii Island. Each site was sampled three times. The total abundance of mollusks was highest in the area of low G. salicornia abundance but there was no significant difference. The total number of mollusk species was significantly higher in the area of high G. salicornia abundance. The fact that more mollusk species occupy the area of high G. salicornia abundance suggests that this invasive species of alga does have a positive effect on species diversity in at least some local taxa.