Predicting Ecosystem Change and Damage
National and Scientific Challenges
Toxic contaminants pose threats to the air we breathe, the food we eat, and the water we drink — in short, the environment in which we live. There is continual debate and much legislation around issues of pollution and environmental health. Unfortunately, our current approach to assessing environmental change by monitoring pollutants and species is inefficient, expensive and often non-predictive. The complexity, uniqueness and diversity of ecological systems increases tremendously the challenges associated with understanding and predicting ecosystem health and stability. Often genetic and genomic information for constituent organisms in these eco-communities have not been, or cannot be, obtained. This is especially the case when microbial communities are the target of assessment. New methods are needed to assess ecosystem health and detect instability before cascading biological effects progress to a point where corrective actions are no longer possible. PNNL is addressing these scientific challenges with the intent to develop suites of molecular level biomarkers that can quantitatively describe biodiversity, system behavior & multiple stressors across levels, in the absence of genomic information. Our first demonstration will address phylogenetically diverse periphyton and microbial communities. Scientists will devise methods for biomarker discovery in response to a specific contaminant to better understand the entry of this contaminant at the sediment-water interface in aquatic systems.
PNNL's Integrative Approach
Our integrative approach will be demonstrated through a suite of projects that center on a particular ecosystem and measure the changes introduced into that ecosystem through the use of chemical, physical and molecular biological technologies. As a model ecosystem, the freshwater hyporheic zone (HZ), the zone where groundwater and surface water meet, represents an important but understudied and poorly characterized model for understanding contaminant mediated changes in microbial community dynamics. The HZ is a critical interface between transport of contaminants through the groundwater and into the surface water due to the shift in physical and chemical characteristics of these two types of media. Microbial organisms that inhabit these different media will also be affected by contaminant(s) and may also play a role in the fate and transport of the contaminant(s). The research hypothesis is that microbial communities (prokaryotic and eukaryotic) in uranium contaminated groundwater differ from river water sediment and hyporheic zone microbial communities in terms of diversity and metabolic function.
Projects
To address the hypothesis, projects will collect molecular biological, chemical and physical data from samples generated in a hyporheic mesocosm. Projects are described below.
- Community-based Biomarkers of Exposure and Functional response in the Sediment/Water Interface of the Hyporheic Zone in River Systems
- The Tree of Life Chip for Examination of Ecosystem Structure and Function
- Identification of Proteomic Profiles and Biomarkers in Complex Microbial Systems Absent of Genomic Sequence Data
- Using Subtractive Hybridization to Identify Biomarkers of Perturbed Microbial Communities
- Nanomaterial Fate, Transport and Transformation in a Freshwater Mesocosm
- PCR Arrays for Quantitative Evaluation of Microbial Communities
Focus Area Point of Contact: Ann Miracle