Meeting Abstract

P1.54  Monday, Jan. 4  High resolution measurements of intertidal relative humidity O’DONNELL, M.J.**; CARRINGTON, E.C.; Friday Harbor Labs, Univ. of Washington; Friday Harbor Labs, Univ. of Washington mooseo@uw.edu

Intertidal organisms are subjected to thermal and desiccation stresses during the aerial part of the tidal cycle. Temperatures in this habitat have been well quantified at a variety of spatial and temporal scales. Desiccation stress, however, is less well understood due to the complexity of measuring relative humidity at appropriate temporal and spatial scales. Biotic and abiotic features of intertidal habitats, such as crevices and patches of algae, are known to retain water during low tide creating protected microhabitats. In this study we documented the relative humidity environment around crevices and algae patches throughout low tides to document the extent to which these microhabitats ameliorate stressful conditions at low tide. Consistent with expectations, crevices and the region beneath algae were more humid than bare rock throughout the tidal cycle resulting in a refuge from high temperature and desiccation. The resulting data provide useful basis to parameterize heat budget models.