Impact of Microplastic Exposure on Sand Crab <i>Scopimera globosa</i> Behavior: Implications for Microplastic Transport and Sulfur Cycling through Bioturbation
Environmental Science & Technology2025
6 citations
?
Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count.
Score: 63
?
0–100 AI score estimating relevance to the microplastics field. Papers below 30 are filtered from public browse.
This study found that microplastic exposure changed the burrowing behavior of sand crabs in estuaries, causing them to dig deeper and avoid contaminated surface sediments. This behavioral shift actually moved microplastics through sediment layers 27 times faster than without the crabs and disrupted important sulfur-cycling bacteria in the soil. The findings show how microplastics can indirectly affect coastal ecosystem processes by altering the behavior of the animals that maintain sediment health.
Study Type
Environmental
The accumulation of microplastics (MPs) in estuarine regions and their ecological consequences have become global environmental concerns. Estuarine sediments function as major sinks for MPs and hotspots for critical biogeochemical processes, which are significantly influenced by benthic bioturbation. However, the impacts of MPs on the behavior of highly mobile benthic organisms and the ecological effects of bioturbation activities remain poorly understood. This study utilized laboratory simulation experiments, AI-based behavioral tracking, and metagenomic sequencing to systematically examine the effects of sand crab bioturbation on MPs migration, sediment physicochemical properties and sulfur cycling processes. Results demonstrated that sand crab bioturbation substantially enhanced the vertical migration of MPs, with fluxes to surface layers and the overlying water increasing by 27-fold compared to undisturbed conditions. Exposure to PE-MPs reduced sand crabs' surface foraging intensity and induced behavioral abnormalities. The crabs actively avoided MPs, exhibiting a preference for burrowing and residing in deeper sediment layers. This behavioral shift significantly altered microbial community distributions, with an increase of <i>Pseudomonadota</i> abundance and a decline of sulfate-reducing bacteria <i>Thermodesulfobacteriota</i> abundance. Furthermore, bioturbation accelerated sulfate oxidation in deeper sediments while inhibited dissimilatory sulfate reduction. This study is the first to identify the role of bioturbation in promoting the upward migration of MPs in sediments. Altered sand crab bioturbation will impact sediment biogeochemistry, estuarine function, and coastal resilience.