Water temperature and food availability are major drivers of the physiological performance of intertidal and shallow subtidal invertebrates, and so the ability to accurately measure and model onshore environments is critical for ecological studies in coastal zones. Because the influence of localized processes such as upwelling, eddy formation, and surface heating from solar radiation, measurements of water temperature and primary productivity measured over large spatial grids (satellites) or at point locations offshore (buoys) are often unable to characterize the environments experienced by organisms onshore. This spatial and temporal ‘mismatch’ between coarse measurements of habitat, the environment experienced by an organism, and the resulting physiological processes driving fitness has led to a number of discussions concerning the importance of scale in ecological processes. However, determining the optimal scale, both temporally and spatially, at which environmental data is collected has remained a challenge in the scientific community and requires understanding the mechanism of interaction between the environment, physiological processes, and organismal fitness. We compared water temperature and primary productivity measured over various spatial scales (satellites, buoys, in situ) from two intertidal sites in central Oregon. We then collapsed and compared data at increasingly longer temporal scales. The resulting data sets were used as inputs to a Dynamic Energy Budget model developed for Mytilus californianus, which describes the investment of energy into processes such as maintenance, growth and reproduction in the context of varying environmental conditions, to quantify how the scale of environmental measurements affect predictions of growth and reproductive output for this species.
Results/Conclusions
Results indicate that at these sites at least, spatially course measurements taken by satellites can only be used as a general indicator of organismal fitness onshore. Predictions using in situ measurements were significantly different than those using measurements at point locations offshore, indicating that environmental variability caused by local oceanographic processes is a major driver of fitness for coastal invertebrates. Furthermore, measurements averaged over large temporal scales had a significant affect on predictions at all spatial scales, further highlighting that small-scale variability in time is a critical driver of organism fitness.