SICB Division of Comparative Biomechanics (DCB)

DCB Researchers Database Entry

Brian Helmuth

A new approach to "ecological triage" in the intertidal zone
Global climate change is expected to cause shifts in species distribution patterns, but recent evidence suggests that knowing where and when to look for such patterns may be more complex than previously anticipated. The intertidal zone is one of the most physically severe environments on earth. Intertidal organisms are thought to live very close to their thermal tolerance limits, and have emerged as a powerful early warning system for the effects of climate change on natural ecosystems. However, while we know that the body temperature affects almost every physiological process studied, we actually know surprisingly little of what their temperatures are under natural field conditions. This gap in our knowledge severely curtails our ability to quantitatively forecast the effects of climate change on the geographic distributions of species in this model ecosystem. Our team has adopted a quantitative approach that connects remote sensing and meteorological data to ground-level models of heat exchange at the scale of intertidal organisms. We use these predictions to explore past, present and future species range boundaries. The project has two inter-related goals. First, we ask, if some aspect of aerial temperature stress limits species range boundaries, then can we predict the location of those range limits using a “climate envelope” approach? A second goal of this project is to develop forecasts of the effects of climate change on the geographic distribution of key ecosystem foundation species in coastal sedimentary and rocky habitats of North America. These approaches will provide predictive power to management decisions. For instance, are changes in distribution or mass mortality part of natural oscillatory cycles, or are they the result of anthropogenic climate change? Are preserves and management areas in locations vulnerable to such changes, and if so can we include risks due to climate change in management decisions?