Ms Zoë Kitchel1, Mr Malin Pinsky1
1Rutgers University, New Brunswick, United States
Changes in climate lead to redistributions of organisms across the globe. Because temperature drives physiological processes such as metabolism and growth, in response to changing temperature organisms adjust location, adapt, or become extinct. In terrestrial systems, geographic barriers, restricted dispersal, and abundant refugia limit the extent to which changes in species’ ranges can match changes in temperature. Marine ecosystems provide fewer obstacles, and therefore serve as natural experiments to examine how changing climate patterns can influence species’ distributions. Here, we assess the associations between ocean temperature and multi-decadal trends in local colonization, extirpation, and species richness in nine marine regions around North America using scientific trawl survey data. We find that magnitude rather than direction of temperature change is useful for explaining change in species richness. Richness is rising in regions experiencing cooling in addition to regions experiencing warming. Additionally, while instances of extirpation are most associated with minimum yearly temperature and seasonality, instances of colonization are most associated with maximum and average yearly temperature. Inconsistent drivers for local colonizations and extirpations can lead to asymmetrical changes in the leading and lagging edges of species distributions. Species traits may further elucidate which climate drivers typically partner with leading and lagging range edges. We predict that these instances of alternative drivers of colonization and extirpation can explain patterns of species range edges on a global scale.
Zoë Kitchel is a graduate student with the Ecology and Evolution Program at Rutgers University where she studies climate change, fisheries, and trait diversity.