Freshwater salinization

I am broadly interested in the environmental, social, and economic consequences associated with freshwater salinization. This includes experimental manipulations, field investigations, and using sensor networks to model risks. My research on freshwater salinization has demonstrated that salts can disrupt the functions of ecological communities, and that different salt types (e.g., CaCl2and MgCl2) toxicologically affect organisms in unique ways. Additionally, road salt additives such as beet juice can act as fertilizers, increasing the productivity of freshwater environments. These results are important, because numerous anthropogenic activities are increasing the salinization of freshwater ecosystems, and unique ions and pollutants are associated with each anthropogenic activity. The results from these studies were used by the European Commission to compose an Environmental Policy Report, promoting that governments in the European Union limit the use of alternative road salts and additives. Additionally, these results led to an invited opinion paper that highlights the need for global, ion-specific regulations and management solutions to protect freshwater environments.

Climate warming and environmental stressors

I use experimental freshwater ponds to understand how climate change interacts with local environmental stressors to affect the structure and function of freshwater food webs. Local stressors that could mediate the effects of climate change include invasive species, nutrient pollution, and increased browning through altered dissolved organic carbon cycles (pictured above). My research has demonstrated that climate warming can negatively affect freshwater environments by altering the distribution of biomass from pelagic to benthic communities. However, the magnitude of these effects depends on the availability of nutrients, the ratio of nutrients and dissolved organic carbon, and the intensity of UV radiation. Additionally, the positive effect of climate change for benthic organisms depends on the presence of invasive species, which can alter nutrient cycling and the biomass of freshwater algae.

Flooding in urban wetlands

The wetland complex (Walker Avenue Wetlands) is a former DOT reclamation site that provides critical habitat for nesting and migrating birds, amphibians, reptiles, and insects. The wetland complex consists of one primary (large) wetland and twenty auxiliary ponds, which are all separated from the Pompton River by a dam and levee. Urban flooding caused by extensive impermeable surfaces in nearby towns and the increased frequency and intensity of storms has resulted in flooding events that completely inundate the wetland, ponds, and river. These events provide an opportunity to study the consequences of environmental homogenization and ecological resilience in a natural wetland system. Each auxiliary pond has unique biota. However, flooding events wash in exogenous species and homogenize the abiotic conditions of the entire wetland complex. Using chemical analyses, shotgun sequencing, and morphological taxonomy, my lab group is investigating the ecological and chemical processes that determine the resiliency of the auxiliary ponds and main wetland.

Mechanisms affecting patterns of diversity

I use experimental and observational approaches to understand how anthropogenic activities and environmental factors affect patterns of species richness. Experimentally, I test fundamental ecological theories using a model zooplankton community. I also investigate how changes to the landscape affect streams and surrounding riparian habitats. These data are used to understand how how environmental factors such as heterogeneity, energy, and habitat area interact to affect species richness patterns. These data are coupled with high-frequency sensor data and food-web models to understand the consequences of anthropogenic activities on ecosystem functions and services.

mescoosm field.mp4