Trace metals pose an environmental risk to aquatic ecosystems once they reach toxic levels in the biota. Measuring the bioaccumulation of trace
metals in different aquatic organisms is an important initial step to understanding the environmental behavior of these contaminants, particularly in
comparative studies with different species1. Secondly, at the subcellular level, we can understand how these elements are handled by aquatic
organisms and their likelihood of being toxic as bioaccumulation increases, which is crucial to predicting metal toxicity 2. Fish collection from the Indian
River Lagoon (IRL) in Florida (USA) envisioned to help with investigating these questions. Pollution from urban, industrial, and agricultural inputs
threaten IRL’s health, leading to polymetallic contamination (e.g., Hg, As, Se) that has raised concerns as the human population continues to expand
alongside this ecosystem3. Although studies focusing on the metal behavior at the subcellular level in fish species have acquired attention over the last
decade, metal handling strategies inside cells in marine fishes are still poorly understood4. Therefore, herein, we will focus on comparing eight marine
fish species of recreational and economic relevance to contribute to bridging the current knowledge gap of metal in marine/estuarine environments.
This internship project comprises two main phases: first, developing an optimized protocol for subcellular partitioning with fish liver in pre-selected
species among the eight (three or four fishes with different contamination levels). Subsequently, subcellular partitioning analysis will be performed
using the optimal protocols to measure metal concentration in hepatocyte’s sensitive and detoxified fractions5. Data analysis will prioritize
understanding coping mechanisms for multiple metals, especially hazardous ones such as Hg, As, and Se, with scarce information, notably in their
mutual interactions. This knowledge will be a powerful tool for predicting trace metal risks within marine ecosystems and produce a more informed
basis for guiding future management decisions.
1. Campbell PG, Giguère A, Bonneris E, Hare L. 2005. Cadmium-handling strategies in two chronically exposed indigenous freshwater organisms—the yellow perch (Perca flavescens) and the floater mollusc (Pyganodon grandis). Aquatic Toxicology, 72(1-2), 83-97.
2. Barst BD, Rosabal M, Campbell PG, Muir DG, Wang X, Köck G, Drevnick PE. 2016. Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient. Environmental Pollution, 212, 574-583.
3. Tremain, D. M., & Schaefer, A. M. 2015. Mercury concentrations in the prey of apex piscivores from a large subtropical estuary. Marine Pollution Bulletin, 95(1), 433–444.
4. Otero-Fariña, A., Rétif, J., Métais, I., Poirier, L., & Châtel, A. 2022. Relevance of cell subcompartmentalization techniques to predict adverse effects of metals in bivalves and fish. Ecological Indicators, 144, 109491.
5. Rosabal, M., Hare, L., & Campbell, P. G. C. 2014. Assessment of a subcellular metal partitioning protocol for aquatic invertebrates: Preservation, homogenization, and subcellular fractionation: Subcellular metal partitioning. Limnology and Oceanography: Methods, 12(7), 507–518.
Knowledge and skills required: cell biology; previous experience with laboratory bench work; ability to process and interpret complex scientific data; attention to details; proactivity; critical thinking; satisfactory communication skills in English (especially reading and speaking).
Preferable knowledge and skills: analytical chemistry; basic/intermediate skills in R Studio; organizational skills; time management; team work.
Application Documents: CV; Motivation letter; Academic transcripts (Bachelor’s and Master’s Degree).