ECOSYSTEM-BASED ENVIRONMENTAL TOXICOLOGY

My research broadly addresses how the continual loading of contaminants is affecting environmental health. Recently, I have been particularly focused on how contaminant effects in freshwater ecosystems are mediated by factors like the biogeochemical cycling of individual pollutants, food web structure, and multiple stressor interactions. I want my work to reflect current challenges in environmental science and inform policies that will both improve aquatic life protection. I gained valuable science translation and communication experience as a PhD student consultant for the Environmental Law & Policy Clinic and member of the Environmental Health Scholars Program. Now, I integrate this training into my research and teaching with the goal of becoming an effective ambassador for science policy and inspiring similar collaboration in the upcoming generation of environmental scientists.


Current Research

Contaminant biotransport by migrating Pacific salmon

 Photo by  Chris Bair  on  Unsplash

Photo by Chris Bair on Unsplash

Many aquatic species travel among ecosystems over the course of their lifetimes, taking with them contaminants stored in their tissues or exoskeletons. Working with David Walters and a team of collaborators, I am interested in quantifying the magnitude of this phenomenon and exploring the trade-offs between contaminant and nutrient loading by salmon in eastern Pacific watersheds . 

Biogeochemical cycling of selenium in lotic food webs

A number of biogeochemical and physical factors control selenium bioaccumulation in aquatic food webs. Using a robust spatial dataset on Lower Gunnison River Basin food webs, I am developing an ecosystem-scale model that will help us more accurately predict fish tissue burdens. This model informs progress with regional selenium management plans and can be manipulated to fit additional ecosystem contexts. This work is in collaboration with Travis Schmidt and other USGS researchers.


Fish otoliths as metabolically stable contaminant RECORDS and TRACERS

 Fish otolith showing LA-ICP-MS Concentrations and age rings.

Fish otolith showing LA-ICP-MS Concentrations and age rings.

Unlike fish tissues - which metabolize and eliminate contaminants over time - fish otoliths are metabolically stable and can serve as life-time records of fish exposure to inorganic elements. For decades, researchers have exploited this trait to understand the migratory patterns of fish that travel between freshwater and saltwater environments and fish exposure to environmental pollutants.

There are two goals of my otolith work. The first is to establish the relationship between otolith and water trace element concentrations so that these biological records can be used to reconstruct historical water quality. The second is to develop a biogenic tracer that can reveal contamination source and exposure timing.

Collaborators: Matt R.V. Ross, Will Clements, Emily S. Bernhardt, Richard Di Giulio


Coal combustion residual distribution in aquatic food webs 

The coal ash waste stream is a source of multivariate stress to freshwater ecosystems and there are now state and federal level regulations addressing this important issue. Trace elements, bound together in coal, are subsequently liberated through excavation, combustion, and treatment processes. In this work, I ask how the elements making up the coal combustion residual (CCR) mixture cycle through aquatic ecosystems? Which elements are sequestered by sediments and which move through aquatic food webs? I also consider how the retention time and size of a given ecosystem influences CCR distribution and how differential element distribution influences the mixture's potential toxicity to higher trophic level animals. 

Collaborators: Marie Simonin, Gary S. Dwyer, Emily S. Bernhardt, Richard Di Giulio, and the NC Wildlife Resources Commission.This work was primarily funded by a grant from the UNC System's Water Resources Research Institute.


 

Related publications

*For updates and my earlier research, see my google scholar page

Published

Brandt, J.E.; Bernhardt, E.S.; Dwyer, G.S.; and Di Giulio, R.T. 2017. Selenium ecotoxicology in freshwater lakes receiving coal combustion residual effluents: A North Carolina example. Environ Sci &Technol. 51 (4): 2418–2426, DOI: 10.1021/acs.est.6b05353

Yang, Y.; Chen, B.; Hower, J.; Schindler, M.; Winkler, C.; Brandt, J.; Di Giulio, R.; Liu, M.; Fu, Y.; Zhang, L.; Priya, S.; and Hochella, M. 2017. Discovery and ramifications of incidental Magneli phase generation and release from industrial coal burning. Nature Communications 8, DOI:10.1038/s41467-017-00276-2

In Revision or Review

Brandt, J.E.; Simonin, M.; Di Giulio, R.T.; and Bernhardt, E.S. Beyond selenium: Coal combustion residuals lead to multi-element enrichment in receiving lake food webs. In revision.

In preparation

Brandt, J.E.; Lauer, N.; Vengosh, A.; Bernhardt, E.S.; Di Giulio, R.T. Strontium isotope ratios in fish otoliths as biogenic tracers of coal combustion residuals inputs to freshwater ecosystems. In prep.

Brandt, J.E.; Humphreys, C.*; Trevisan, R.; Massarsky, A.; Kozal, J.S.; and Di Giulio, R.T. Bioenergetic consequences of dietary seleno-L-methionine exposure in adult zebrafish (Danio rerio) and their offspring. In prep.

* denotes co-supervised undergraduate researcher


Outreach

Art of a Scientist

Jim Lee, a science & technology-inspired artist based in NC, and I paired up for the collaborative art show, Art of a Scientist exhibit at the Rubenstein Arts Center in 2018. Using scanning electron microscopy images of biofilms from my NC Lakes work, Jim created the fictional ecosystem shown here . The final version was mounted onto a biofilm collection plate from my field work.

Think Blue

A Durham-based event, Think Blue brought together water-based NGOs, academic researchers, government scientists, and citizen groups for a public education event. I shared my research on coal ash contamination of NC water resources with the local community.


Research Press