Untangling distribution shifts for improved characterization, prediction, and management

Dr Katherine Mills¹, Dr. Justin Schuetz¹, Mr.  Andrew Allyn¹, Dr. Andrew Pershing¹

¹Gulf Of Maine Research Institute, Portland, United States

Studies of climate-related species range shifts typically focus on changes in range centroids relative to mean annual temperatures for species as a whole. While this approach provides a broad-scale indication of distribution shifts and their relationship to warming, greater depth of analysis may be required to reliably predict distribution shifts and to understand their ecological and socio-economic implications. Using data from marine fish surveys along the Northeast U. S. Shelf, we offer several advances to this approach. First, we investigate the extent to which species distributions track a variety of temperature variables at multiple temporal scales. This analysis reveals that most species track a temperature variable, but specific variable(s) associated with a tracking response differ among species. As such, models of species distribution change based only on mean temperature may not yield reliable predictions. Secondly, we implement and evaluate a classification system to characterize species distribution shifts based not only on the centroid, but also on patterns of change in the leading and trailing edges. Finally, we investigate whether and how subgroups within a species respond differently to the same driver by focusing on size-based intraspecies distinctions in distribution responses to warming. A more holistic characterization of distribution change has important societal and management implications, particularly when there is interest in whether a shift may result in mis-alignment between resources and resource users—a common situation in marine fisheries.

Biography:

Dr. Katherine Mills is a research scientist at the Gulf of Maine Research Institute in Portland, Maine. She earned her Ph.D. in Natural Resources at Cornell University. As a quantitative fisheries ecologist, Kathy studies (1) how physical and ecosystem conditions are changing; (2) how these changes affect fish populations, biological communities, and marine fisheries; and (3) how fisheries and fishing communities can effectively respond. Much of her work is interdisciplinary, seeking to understand and inform management of fisheries as coupled social-ecological systems. This research integrates climate, ecological, social and economic information to link changes in the ecosystem to societal outcomes. Climate adaptation within marine fisheries has become a major recent focus, with emphases on assessing climate adaptation strategies and providing new forms of information to support adaptation planning by fishery participants, fishing communities and fishery managers.