Microplastic pollution, a growing concern in aquatic ecosystems, has been found to significantly impact energy production in a common microscopic creature found in freshwater environments worldwide. A new study conducted by the University of Exeter reveals that severe microplastic contamination negatively affects the symbiotic relationship between Paramecium bursaria and the algae that reside within their cells.
Paramecium bursaria contains algae that live inside its cells, providing energy through the process of photosynthesis. This relationship, known as photosymbiosis, is prevalent in both freshwater and ocean environments. Dr. Ben Makin, the lead author of the study, explains that climate change is already known to damage photosymbiotic relationships, including those in corals, leading to bleaching events. However, recent studies have shown that microplastics may also interfere with photosymbiosis, emphasizing the need for more research, particularly in freshwater habitats.
The researchers exposed Paramecium bursaria to water contaminated with microplastics in laboratory settings, simulating severe contamination levels observed in some natural environments. The study aimed to determine whether severe contamination could affect this critical relationship and identify the possible effects. The research found a significant 50% decline in net photosynthesis, greatly impacting the algae’s ability to produce energy and release oxygen.
Although the study did not identify the exact cause of the observed impacts on photosymbiosis, potential explanations include the ingestion of plastic particles by Paramecium bursaria or chemicals from the plastics affecting biological processes. Further research is needed to explore different microplastic concentrations, types of plastic, and effects on other species.
The findings raise concern for the essential contributions of photosymbiosis to primary production on a global scale. Photosymbiosis is responsible for approximately half of all oceanic photosynthesis, underpinning the “trade” in nutrients that allows these relationships to persist. Dr. Makin highlights that microplastics are a widespread contaminant, and their impacts on photosymbiosis, especially in freshwater environments, remain poorly characterized.
This groundbreaking study, published in the journal Aquatic Biology, is titled “Microplastic contamination reduces productivity in a widespread freshwater photosymbiosis.” The research emphasizes the need for more extensive studies on microplastic pollution and its effects on the delicate balance of aquatic ecosystems.
Microplastic contamination reduces productivity in a widespread freshwater photosymbiosis, Aquatic Biology (2023). discovery