Aquatic Health Program

Myctophid from N. Pacific Gyre with microplastic
Cocktail of toxicants that can be associated with plastic debris in aquatic habitats
Laboratory dietary exposure of plastic debris to a medaka fish model

Plastics Debris

Plastic Debris in Aquatic Habitats

The infiltration of plastic debris into aquatic habitats has become a global environmental problem. To better understand the hazards of plastic debris in aquatic habitats we are currently researching:

1. The occurrence of contamination from plastic debris in the N. Pacific and S. Atlantic Gyre

Aboard a research vessel with Scripps Institution of Oceanography and Project Kaisei, led by Dr Miriam Goldstein, and aboard a sailboat across the S. Atlantic (from Rio de Janeiro to Cape Town), led by 5Gyres, we reached subtropical gyres where plastic debris accumulates. Aboard both cruises, we observed plastic debris in almost every sample. Our interest aboard both cruises was to quantify hazardous chemicals sorbed to recovered plastic debris, measure chemicals that may be associated with plastics in ambient seawater and measure ingestion of plastic and bioaccumulation of hazardous chemicals in fish. Using observational, or mensurative, experiments we are trying to better understand the occurrence of hazardous chemicals on plastic debris, potential contamination in the water from plastic debris and ingestion and bioaccumulation in fish.

2. The cocktail of toxicants associated with different types of plastic debris.

The physical and chemical properties of plastic debris facilitates the sorption of several hazardous chemicals to the material itself. Organic chemicals such as pesticides, flame retardants and petroleum hydrocarbons and metals such as lead and copper are found sorbed to plastic material globally. As a result, plastic debris in aquatic habitats is associated with a “cocktail of contaminants” that may be hazardous to aquatic animals upon ingestion. We have found that this “cocktail of contaminants” varies by plastic type and by location where the debris is discarded. Thus, hazards associated with plastic debris may vary by polymer and location having implications for the management of our plastic waste.

3. Toxicity to fish

The ingestion of plastic debris is reported in a large range of aquatic organisms across multiple trophic levels. More specifically, plastic debris has been reportedly found in the gut contents of both demersal and pelagic fish globally from bays and estuaries to the open ocean.  Fish, one of the most diverse groups of animals and of great ecological- and commercial- importance, are useful as sensitive indicators of effects associated with stressors in aquatic habitats. To understand hazards associated with the ingestion of plastic debris in aquatic organisms, we began with the model laboratory fish, Japanese medaka (Oryzias latipes). Through a chronic dietary exposure, we are measuring the bioaccumulation of chemicals from plastics and associated health effects. Model organisms help us understand the baseline toxicity to an organism from a stressor and allow us to better understand if what we observe in the wild is a consequence of exposure to our contaminant of concern. 

 Publications

- Environmental Science and Technology, Long-Term Field Measurement of Sorption of Organic Contaminants to Five Types of Plastic Pellets: Implications for Plastic Marine Debris

 http://pubs.acs.org/doi/abs/10.1021/es303700s 

- Chemosphere, Persistent organic pollutants in plastic marine debris found on beaches in San Diego, California

 http://www.sciencedirect.com/science/article/pii/S0045653511010836




Photo: Chelsea Rochman, Ph.D. Candidate

Chelsea Rochman, Ph.D. Candidate

I am a PhD candidate in the Joint Doctoral Program in Ecology with UC Davis and San Diego State University with areas of emphasis in Marine Ecology and Environmental Toxicology/Chemistry. Particularly, I am interested in sorption of persistent organic contaminants (PAHs,PCBs, OCs, and PBDEs) to plastic debris in the marine environment and from plastic debris (nonylphenol, styrenes and flame retardant) into the marine environment. My main interests involve how toxicants associated with marine plastics transfer to organisms upon ingestion and consequently affect their health. Outside of my dissertation research I have attended several policy meetings regarding this environmental issue and am participating in an NCEAS working group focused on marine debris. I also participate in outreach activities such as the Girls in Ocean Science Conference in Dana Pt, CA to translate my research beyond academia. My ultimate career goal is to stay in academia and continue to research environmental toxicology/chemistry while educating the community through public outreach to inform science, policy and the general public.

Email: chelsear@sciences.sdsu.edu

Website: www.chelsearochman.com