USS and Stanford University Study Microplastics in Patagonia’s Fjords

The initiative, led by Dr. Lara Marcus, combines fieldwork, technology transfer, and international scientific cooperation to evaluate the impact of microplastics on the marine food web.

Universidad San Sebastián (USS), through its Faculty of Science, has developed a research project in collaboration with Stanford University, aimed at studying microplastic pollution and its effects on the marine food web of the Patagonian fjords. The initiative is led by Dr. Lara Marcus, a biologist, academic, and researcher at the USS Patagonia Campus. As part of the project, she hosted a team of Stanford University researchers for a ten-day joint scientific field campaign.

This international collaboration builds on an ongoing academic partnership between Dr. Marcus and Dr. Manu Prakash of Stanford University that began in 2017. In 2023, they jointly developed a citizen science project that used the Foldscope—a paper-based microscope invented by Prakash—to monitor harmful algal blooms. The initiative, called Sea-Watchers, was funded through a public engagement grant and aimed to establish local environmental observers to support marine conservation.

Impact of Microplastics on the Marine Food Web

This research seeks to evaluate:

• The extent of microplastic pollution in Chilean Patagonia.
• The distribution of microplastics throughout the water column.
• The identification of their main sources.

“Understanding how this pollution affects the marine food web and evaluating ecosystem health, as well as its potential impact on human populations, is essential,” explained Dr. Marcus.

The researcher emphasized that this type of pollution affects organisms across multiple trophic levels. “Microplastics can be ingested by microscopic organisms such as zooplankton, as well as by large species such as whales. In addition, plastics release toxic chemical compounds that can affect marine ecosystem health and may pose potential risks to humans,” she added.

Fieldwork and Capacity Building

As part of the project, the research vessel Centinela I, conducted a scientific expedition to collect samples from the inland sea of Chiloé and the Reloncaví area.

“These are highly productive ecosystems that are subject to significant anthropogenic pressure. Therefore, we are focusing our sampling efforts on areas where substantial microplastic accumulation is expected,” said Dr. Marcus.

Researchers collected water samples and representative organisms from different levels of the food web, including phytoplankton, fish, shellfish, and biopsy samples from marine mammals. The objective is to determine whether microplastics are already being ingested by these organisms and whether toxic compounds are bioaccumulating in their tissues. Such accumulation could cause cellular, physiological, and reproductive effects, with important implications for both ecosystem and human health.

The Stanford researchers’ visit also included work at the scientific station of the San Ignacio del Huinay Foundation, located in Comau Fjord, with participation from the Fisheries Development Institute (Instituto de Fomento Pesquero). According to Dr. Marcus, “The main objective of this campaign is to understand primary production dynamics throughout the water column in the Patagonian fjords and to evaluate how these processes are being modified by climate change and other anthropogenic pressures.”

A central component of the collaboration with Stanford University is technology transfer and specialized training for the Chilean research team in the use of advanced microscopy equipment and plankton monitoring techniques. “This process will allow us to incorporate these technologies in Chile and strengthen local capacities for studying and monitoring Patagonian marine ecosystems,” she concluded.

Participating Team

The scientific team includes researchers from several national and international institutions and is led by Dr. Lara Marcus. Representing Stanford University are Dr. Manu Prakash and researchers Charlotte Branon and Alexander Lefell. Dr. Jorge Mardones participates on behalf of the Fisheries Development Institute (IFOP), while Dr. José Luis Iriarte represents the Austral University of Chile.