Marine plankton tells the long story of the health of the oceans, and perhaps of people
Using samples from an ongoing study of nearly a century-old marine plankton, researchers at the University of California, San Diego School of Medicine suggest that rising levels of chemicals found in parts of the world’s oceans could be used to track the effects of human activity on human activity. ecosystem health and can one day be used to study the relationship between ocean pollution and surface pollution rates.Chronic childhood and adult diseases.
The results were published in the January 6, 2023 issue of the journal General Environmental Science.
“This was a pilot study to test the feasibility of using archived plankton samples from the CPR (Permanent Plankton Recorder) survey to reconstruct historical trends in marine pollution in space and time,” said lead author Robert K. Naviaux, MD, PhD. Professor of Medicine, Pediatrics and Pathology at UC San Diego School of Medicine. “We were prompted to explore these new methods by the alarming increase in chronic diseases in children and adults worldwide since the 1980s.
“Recent studies have highlighted the close relationship between ocean pollution and human health. In this study, we asked: Are changes in plankton exposure (a measure of lifetime exposure) associated with the health of ecosystems and fisheries?
“We also wanted to set the stage for asking a second question: Can man-made chemicals in plankton be used as a barometer to measure changes in the global chemosphere that can cause childhood and adult disease?” In other words, we wanted to test the hypothesis. the rapid renewal of plankton and its tendency to foul can make it the marine version of the canary in the coal mine. »
The UK-based CPR Survey is the oldest and most geographically extensive study of marine ecology. Since 1931, nearly 300 vessels have traveled more than 7.2 million miles with tows taking measurements of plankton and the environment in all the world’s oceans, the Mediterranean Sea, the Baltic Sea, and the North Sea and in freshwater lakes.
The effort, along with complementary programs elsewhere, aims to document and monitor the overall health of the oceans based on the well-being of marine plankton—a diverse collection of typically small organisms that provide food for many other aquatic creatures, from shellfish to marine life. whaling.
“Marine plankton are present in all ocean ecosystems,” said study co-author Sonia Batten, PhD, former coordinator of the Pacific CPR and current executive secretary of the North Pacific Marine Science Organization. “They form complex communities that form the base of the food web and play an important role in maintaining the health and balance of the oceans. Plankton are generally short-lived and very sensitive to environmental changes. »
Corresponding co-author Kefeng Li, PhD, a project scientist in Naviaux’s lab, and his colleagues evaluated plankton samples collected from three different locations in the North Pacific Ocean at different times between 2002 and 2020, then used different technologies to assess their exposure. to various artificial chemicals, including pharmaceutical products; persistent organic pollutants (POPs) such as industrial chemicals; pesticide; phthalates and plasticizers (chemicals derived from plastic); and personal care products.
Many of these pollutants have declined over the past two decades, but not universally and often comprehensively, according to the researchers. For example, analyzes show that levels of older POPs and the generic antibiotic amoxicillin have declined significantly in the North Pacific over the past 20 years, possibly due in part to regulations by the federal government and reductions in overall antibiotic use in the United States and Canada, but results in Russia and China distorted by the simultaneous increase in consumption.
The most contaminated samples were taken from coastal areas closest to human activity and subject to events such as soil runoff and aquaculture. At these sites, higher levels and greater numbers of different chemicals were found in the plankton taxa living in these coastal environments.
The authors said their pilot project paves the way for further research designed to examine the relationship between plankton exposure, predator-prey relationships and impacted fisheries.
“Further research by epidemiologists and marine ecologists is needed to test whether and how plankton excretion is linked to important medical trends in nearby human populations, such as infant mortality, autism, asthma, diabetes and dementia,” Naviaux said.
Naviaux noted that the findings provide new clues to explain the nature of many chronic diseases in which phases of the cellular danger response (CDR) persist and result in chronic symptoms.
For more than a decade, Naviaux and his colleagues have gathered data to suggest that many chronic diseases and illnesses, from neurodegenerative diseases such as autism spectrum disorders and neurodegenerative disorders such as ALS, to cancer and major depression, are at least partly the result of metabolic processes. Dysfunction resulting in incomplete healing characterized as CDR.
Naviaux has published extensively on this topic, including how environmental factors that contribute to metabolic dysfunction and chronic disease can affect CDR.
“The purpose of CDR is to help protect the cell and restart the healing process after injury by causing the cell membranes to stiffen, reduce and change their interactions with neighbors, directing energy and resources for defense until the threat is over,” said Naviaux.
“But sometimes CDR gets stuck. This alters the cell’s response to the world, preventing it from completing its natural healing cycle. When this happens, the cells behave as if they are still injured or in imminent danger, even though the original cause of injury or danger has passed. We have learned that many environmental chemicals, trauma, infections or other types of stress can delay or block the completion of the healing cycle. When this happens, it causes symptoms of a chronic disease. ”
“CDR is a whole-body process that starts with the mitochondria and the cell. Mitochondria are cellular organelles that act as biosentinels that constantly monitor the cell’s chemistry and environment. Mitochondria regulate metabolic activity necessary for energy and movement, innate immunity, regulating the health of the microbiome, and preparing the building blocks needed for tissue repair after injury. »
In a marine plankton study, Naviaux and his co-authors found that the plankton exposome was dominated by perfluoroalkyl substances (chemicals commonly used to waterproof everyday products ranging from packaging to clothing to kitchen utensils).
These substances are known to inhibit certain mitochondrial proteins, including an important enzyme used to regulate cortisol metabolism and the body’s response to stress. Other chemicals found include phthalates from plastics and personal care products such as lotions and shampoos. Phthalates are endocrine disruptors that have been increasing in plankton excretion for over 20 years and have both direct and indirect effects on mitochondria.
“Plankton respond to the chemicals they’re exposed to, in part with changes in their mitochondria that change their biology,” Naviaux said, “and I’d say humans do, too.” I hope that the use of our methods by research groups around the world will strengthen the link between ecosystem health and human health and provide new tools to track the evolution of the human chemical footprint over the century.
“If the links are strong enough, plankton exposures from observatories around the world could be used to monitor and reduce pollution that causes human disease in the future. »
Co-authors include: Jane C. Naviaux, Sai Sachin Lingampelly, Lin Wang, and Jonathan M. Monk, all at UC San Diego; and Claire M. Taylor and Clare Ostle, both of the Marine Biological Association.
Funding for this research came in part from a consortium of funders through the North Pacific Marine Science Organization, the North Pacific Research Council, the Spill Management Board, Exxon Valdez, Gulf Watch Alaska, and Fisheries Canada. and the Oceans and Marine Biological Association; UC San Diego Christini Foundation and Lennox Foundation.