We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Size- and shape-dependent ingestion and acute toxicity of fragmented and spherical microplastics in the absence and presence of prey on two marine zooplankton
Summary
Researchers tested how the size and shape of microplastics affect their toxicity to tiny marine animals called zooplankton. Smaller particles were swallowed more often, but irregularly shaped fragments were more toxic than smooth spheres of similar size. When natural food was present, the animals ate fewer microplastics, suggesting that real-world toxicity depends on both particle characteristics and environmental conditions.
As microplastics (MPs) are particulate pollutants, their size and shape, and the presence of prey in the media can affect their toxicity. However, the size- and shape-dependent toxicities of MPs and their prey-dependent ingestion patterns in marine zooplankton are not well understood. Thus, we investigated the ingestion and egestion patterns, and toxicity of different shapes and sizes of MPs on two marine zooplankton, Brachionus koreanus and Diaphanosoma celebensis, under different prey conditions. The ingestion assay showed that smaller MPs were ingested more frequently, regardless of their shape. However, fragmented MPs showed higher toxicity than spherical MPs of comparable size. Prey in the media reduced the uptake and toxicity of MPs in both species depending on the taxa's feeding strategy. Our findings demonstrate that the size and shape of MPs are important factors in determining toxicity and that the presence of prey should also be considered when assessing MP toxicity.
Sign in to start a discussion.
More Papers Like This
Size matters more than shape: Ingestion of primary and secondary microplastics by small predators
Researchers offered irregularly shaped secondary microplastics — fragments more realistic than the perfect spheres used in most lab studies — to small fish and shrimp at natural concentrations, finding that particle size was a stronger predictor of ingestion than shape. The study underscores that lab results using uniform plastic beads may overestimate real-world microplastic uptake in marine food webs.
Size-dependent chronic toxicity of fragmented polyethylene microplastics to Daphnia magna
Researchers tested the long-term effects of irregularly shaped polyethylene microplastic fragments on the freshwater organism Daphnia magna over 21 days. They found that fragmented microplastics were ingested at much higher rates and caused more harm to reproduction and survival than smooth, round plastic beads of similar size, suggesting particle shape matters for toxicity.
Size- and shape-dependent effects of microplastic particles on adult daggerblade grass shrimp (Palaemonetes pugio)
Researchers exposed adult grass shrimp to eleven sizes of microplastic spheres, fibers, and fragments and measured effects on survival, ingestion, and particle residence time. They found that mortality was size- and shape-dependent, with larger spheres and fibers causing the highest death rates, while particles smaller than 50 micrometers were not acutely toxic. The study demonstrates that both the size and shape of microplastics are critical factors in determining their toxicity to marine crustaceans.
Bioavailability of Microplastics to Marine Zooplankton: Effect of Shape and Infochemicals
The influence of microplastic shape (bead, fiber, and fragment) and algal infochemicals (DMS and DMSP) on microplastic ingestion by marine zooplankton was investigated. Shape significantly affected ingestion rates, and infochemicals influenced zooplankton feeding behavior in ways that altered microplastic uptake, revealing how chemical cues in the ocean shape plastic particle ingestion.
Bioavailability and effects of microplastics on marine zooplankton: A review
This review synthesized laboratory and field evidence on microplastic bioavailability and effects on marine zooplankton, finding that multiple taxa readily ingest microplastics with negative impacts on feeding, reproduction, and energy balance, and that zooplankton represent a critical route for transferring microplastics into marine food webs. The authors identify particle size, concentration, and feeding behavior as the main determinants of microplastic bioavailability to zooplankton.