COS 94-9 - Managing multiple stressors: Applying the exposome concept from human health to freshwater lakes

Friday, August 12, 2016: 10:30 AM
124/125, Ft Lauderdale Convention Center
Kathryn L. Cottingham, Biological Sciences, Dartmouth, Hanover, NH and Cayelan C. Carey, Biological Sciences, Virginia Tech, Blacksburg, VA
Background/Question/Methods

Although some ecologists refer to the ‘health’ of an ecosystem, they rarely view ecosystems from a medical perspective, even though there are several parallels between ecosystem functioning and human health.  Using freshwater lakes as our focal study system, we are using a transdisciplinary approach to investigate how local, regional, and global stressors - including invasive species, land use change, and climate change - interact to impact water quality and the provisioning of essential ecosystem services.  The potential for individual stressors to have both direct and indirect effects, combined with the potential for interactions among stressors, pose major challenges for managers.  For example, climate change is expected to impact freshwater organisms not only through increased water temperatures, but also via altered thermal stratification and precipitation regimes, and to have differential impacts depending on food web structure.  We hypothesize that the concept of the exposome, recently developed to evaluate the interactive effects of multiple stressors on human health, may have useful implications for ecologists and lake managers because of its emphasis on considering the sum total of exposures within the context of an individual’s unique characteristics.  Here, we will use this recently-developed conceptual framework to evaluate current challenges in lake management.

Results/Conclusions

Our work to date suggests that the exposome framework provides a useful platform for understanding multiple stressors and holds useful lessons that may lead to innovative, context-dependent management approaches.  For example, a key tenet of the exposome is that human health is determined by an interaction between individual exposures to particular stressors (beginning in utero and continuing through life) and the unique characteristics of that individual (e.g., genetics, epigenetics, physiology):  i.e., that there is no universal outcome for exposure X to lead to outcome Y.  Thus, similar to the ecological concept of context dependency, the exposome framework suggests that a one-size-fits-all management strategy may be less effective than a strategy that specifically takes into account how a particular stressor or stressors will interact with the unique characteristics of that lake.  This is consistent with the idea that a lake’s morphometry, water residence time, and existing nutrient storage in the sediments combine to modulate the impacts of increased or decreased nutrient loading; ignoring these factors can lead to costly, but ineffective, management.  Next steps include evaluating the parallels between the exposome concept’s focus on identifying measurable disease precursors that precede overt disease and the ecological concept of early warning indicators.