Influence of Microplastics on the Nutritional and Locomotive Activity of Dinoflagellate Oxyrrhis marina under Experimental Conditions
The incorporation of microplastic particles (MPs) into the microbial food web and their impact on physiology of consuming organisms remains largely underexplored. The heterotrophic dinoflagellate Oxyrrhis marina is an excellent model for understanding these processes. In this study, flow cytometry w...
Gespeichert in:
Veröffentlicht in: | Inland water biology 2024-04, Vol.17 (2), p.316-326 |
---|---|
Hauptverfasser: | , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The incorporation of microplastic particles (MPs) into the microbial food web and their impact on physiology of consuming organisms remains largely underexplored. The heterotrophic dinoflagellate
Oxyrrhis marina
is an excellent model for understanding these processes. In this study, flow cytometry was used to analyze the dynamics of consumption by this predator of its natural prey, the microalga
Isochrysis galbana
(ISO), and plastic microspheres (MS) of the same size. Furthermore, the effects of the diets containing these components on the swimming speed and movement patterns of
Oxyrrhis marina
cells were assessed. This was achieved using a computational method for analyzing video recordings of
O. marina
movement. It was observed from the first minutes of the experiment that the dinoflagellates actively consumed both types of prey, but by the end of the experiment, the number of MS in the medium decreased to a lesser extent, from 4.4 to 2.2 × 10
5
cells/mL, while
Isochrysis galbana
cells were almost completely grazed, with their abundance dropping by more than two orders of magnitude, from 4.9 × 10
5
cells/mL to 2.3 × 10
3
cells/mL. Such dynamics were associated with a compensatory increase in the number of microspheres in the medium due to their excretion and repeated phagocytosis by
Oxyrrhis marina
. Interestingly, the ingestion of plastic microspheres, which led to an increase in dinoflagellate cell size, did not significantly reduce their mobility or impair their locomotion. The ‘unproductive’ consumption of microplastics, which provided no nutritional benefit, resulted in a statistically significant reduction in dinoflagellate abundance compared to controls and the microalgae-fed experiment. This decline was attributed to the high energy expenditure of the population in constantly searching for, phagocytosing, and excreting microspheres. Contrary to expectations, the predators did not abandon this unproductive feeding strategy. Instead, their cell mobility increased over time, exacerbating the situation. These processes could have far-reaching negative implications for the entire food web. Specifically, microplastics 'packaged' by unicellular organisms could be transferred to higher trophic levels, potentially accumulating in mollusks, fish, and larger predators. |
---|---|
ISSN: | 1995-0829 1995-0837 |
DOI: | 10.1134/S1995082924020135 |