Marine and Freshwater Ecosystems Impact and Toxicology - Theme 5 (MFW)
Leader: Hunter Lenihan
Theme 5 has a specific focus on aquatic (marine and freshwater) ecosystems. The overarching goal of Theme 5 to address questions about the impacts of engineered nanomaterials (ENMs) on key ecological processes that help to control the abundance and distribution of organisms in freshwater and marine ecosystems. Researchers in this Theme test hypotheses involving individuals, populations, and communities of flora and fauna that perform ecological processes that help to generate important ecosystem services, including the maintenance of biodiversity, water quality, food webs, nutrient cycling, and the provision of economic resources for humans. The work is conducted with studies of the embryos of marine organisms, which is essential for identifying possible adverse effects of nanomaterials on development in early life stages. Work in vivo and in vitro with organelles, cells, and tissues of adult marine animals provide insight into the responses of individual whole organisms and populations. This body of work, conducted by Prof. Gary Cherr at UC Davis, has strong intellectual overlap with the work in Theme 2 conducted by Dr. Andre Nel’s group on mammalian cells and zebrafish, and work in Theme 4 by Prof. Trish Holden’s group working with bacteria. We study freshwater and marine phytoplankton and cyanobacteria, single celled organisms that form the basis of aquatic food webs, and thus generate most of the world’s primary production. Our experiments with phytoplankton include high-content screening (HCS) of these single celled plantsn that is designed to identify multiple cytotoxic/organellar endpoints. Results from HCS experiments are used to understand the mechanism of injury that lead to changes in phytoplankton population growth rates (and thus primary production). We also study suspension-feeding marine mussels that bioprocess and bioaccumulate nanomaterial contaminants; copepods that graze upon phytoplankton, and thus represent an important pathway of ENM trophic transfer; marine and freshwater benthic invertebrates that provide excellent ecological templates for the impacts of ENMs in marine sedimentary habitats; and CA spiny lobster that prey on mussels and influence marine food webs in many ways. Finally, we are modeling the general ecological impacts of ENMs through the powerful tools associated with Dynamic Energy Budget (DEB) modeling. As such, several of our experiments are designed specifically to generate data for DEB models designed to identify how ENMs influence energy transfer and propagate within individuals, populations, and communities to influence ecological processes at higher level of organization within aquatic ecosystems.
1. Marine Organismal Nanotoxicology: Studying Nanomaterials’ (NMs) Interactions at the Molecular, Cellular, Organ, and Systemic Levels
2. Impacts of Engineered Nanomaterials on Marine Ecosystems
3. Decoupling and Recoupling Plant-Herbivore Systems to Determine the Fate and Impact of Nanomaterials in Freshwater Environments
4. Impacts of TiO2 Nanoparticles on Freshwater Food Webs
5. Dynamic Energy Budget (DEB) Modeling To Support Design of Aquatic Microcosm and Mesocosm Experiments