Microplastics, one of the most persistent forms of environmental pollution today, can affect the reproductive capacity of organisms that are essential to freshwater ecosystems.
Authored by Bruno Nunes (pictured), a CESAM/DBIO researcher, João Pinto da Costa, a CESAM/DQ researcher, David Daniel and Madalena Vieira, PhD students at CESAM/DBIO, and Ana Violeta Girão, from CICECO, the study reveals that both types of microplastics significantly reduced reproductive parameters in D. magna, namely the number of offspring produced. This reduction may have significant implications for the populations of these organisms and, consequently, for the food chains of which they are part.
The findings come from a study by the University of Aveiro (UA) that analysed the impact of widely used plastic particles on Daphnia magna, a small crustacean commonly known as the water flea, which plays a key role in aquatic food chains.
Plastic pollution has increased significantly in recent decades. When these materials reach rivers, lakes and oceans, they progressively degrade, giving rise to microscopic particles known as microplastics. Due to their small size, these particles can be ingested by various aquatic organisms, with potential consequences for their health and for the balance of ecosystems.
In the study, the researchers assessed the effects of two commonly used types of microplastics: polyethylene terephthalate (PET), used, for example, in beverage bottles, and polypropylene (PP), found in numerous types of packaging and everyday objects.
In addition to the effects on reproduction, the researchers observed temporary changes in biological mechanisms associated with stress response and the elimination of potentially toxic substances. However, these changes were more evident during short-term exposure and tended to disappear in organisms subjected to prolonged exposure.
According to the authors, this pattern suggests that the animals may develop mechanisms to adapt to the continued presence of microplastics. Nevertheless, this adaptation does not appear to prevent the negative impacts observed on reproduction.
The study reinforces growing concerns about the presence of microplastics in aquatic ecosystems and highlights the need to reduce the release of these contaminants into the environment in order to protect biodiversity and the functioning of natural systems.
Original news article in UA Online, 21 September 2026