Marine and Freshwater Ecosystems Impact and Toxicology

Leader: Roger M. Nisbet

Theme 5 research has two distinct thrusts:  studies of biological injury mechanisms in freshwater and marine organisms together with studies that aim to characterize feedbacks and ecological interactions that influence how these injuries translate to impacts on ecosystem services.  The two research directions are interconnected because effects of exposure to engineered nanomaterials in the environment potentially manifest themselves at all levels of biological organization (cell, organism, population, community, ecosystem), with the sequence of key events linking the molecular level initiating events to ecologically important outcomes increasingly referred to as Adverse Outcome Pathways (AOPs).  Testing predictions of impacts on populations or on ecosystem services requires long term experiments testing specific hypotheses with carefully selected nanomaterials. Quantitative predictions at population, community and ecosystem level also require systems modeling, and theme 5 research places particular emphasis on dynamic energy budget models that describe impacts on fundamental biological processes common to most organisms.

Theme 5 research on injury mechanisms for marine organisms shares same goals with Theme 2, but focuses on marine, estuarine and freshwater organisms.  Other theme 5 research relates these findings, and other supporting data, to ecologically important effects on populations and ecosystem processes.  There is also a seed project on biodiversity. Specific theme 5 goals are:

(i) to conduct high content and high throughput screening of marine and freshwater organisms to link mechanisms of injury to specific ENM properties;

(ii) to perform individual- and population-level microcosm exposures to assess the impact of specific injury mechanisms on organisms and populations;

(iii) to use predictions based on HCS and microcosms to evaluate ENMs with the highest-risk properties in mesocosm and case studies to quantify ecosystem-level effects and'

(iv) to develop predictive systems models of ENM impacts through dynamic energy budget (DEB) modeling.