We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Biofouling on buoyant marine plastics: An experimental study into the effect of size on surface longevity
AI summary Read the abstract
Researchers tested how quickly marine organisms colonize floating plastic debris of different sizes and whether this biofouling causes the plastics to sink. They found that smaller microplastics accumulated enough biological growth to lose buoyancy and begin sinking within weeks, much faster than larger pieces. The study helps explain why smaller microplastics are unexpectedly scarce at the ocean surface, as biofouling may be rapidly transporting them to deeper waters and sediments.
Recent estimates suggest that roughly 100 times more plastic litter enters the sea than is found floating at the sea surface, despite the buoyancy and durability of many plastic polymers. Biofouling by marine biota is one possible mechanism responsible for this discrepancy. Microplastics (<5 mm in diameter) are more scarce than larger size classes, which makes sense because fouling is a function of surface area whereas buoyancy is a function of volume; the smaller an object, the greater its relative surface area. We tested whether plastic items with high surface area to volume ratios sank more rapidly by submerging 15 different sizes of polyethylene samples in False Bay, South Africa, for 12 weeks to determine the time required for samples to sink. All samples became sufficiently fouled to sink within the study period, but small samples lost buoyancy much faster than larger ones. There was a direct relationship between sample volume (buoyancy) and the time to attain a 50% probability of sinking, which ranged from 17 to 66 days of exposure. Our results provide the first estimates of the longevity of different sizes of plastic debris at the ocean surface. Further research is required to determine how fouling rates differ on free floating debris in different regions and in different types of marine environments. Such estimates could be used to improve model predictions of the distribution and abundance of floating plastic debris globally.
More Papers Like This
The role of buoyancy in the dispersal of marine plastic debris and the impact of biofouling : does size matter?
AI summary Read the abstract
This thesis examined why smaller microplastic particles (less than 5mm) appear to be disappearing from the ocean surface at higher rates than expected, investigating how biofouling—colonization by organisms that adds weight—affects the buoyancy and sinking of differently sized plastic items. The study found that size significantly influences how biofouling affects plastic transport, with smaller particles more prone to sinking.
Experimental assessment of settling velocity of pristine and biofouled microplastics
AI summary Read the abstract
Researchers experimentally measured how biofouling alters the settling velocity of microplastic particles, finding that biofilm growth on buoyant plastic fragments caused them to sink more rapidly. The results demonstrate that biological colonization of plastic surfaces is a key mechanism driving the vertical transport of microplastics from surface water to the seafloor.
Effects of biofouling on the sinking behavior of microplastics
AI summary Read the abstract
Researchers studied how biofouling — the accumulation of microorganisms and organic matter on particle surfaces — alters the sinking behavior of microplastics, finding that biofouled particles sink faster and are more likely to reach seafloor sediments.
Biofouling impacts on polyethylene density and sinking in coastal waters: A macro/micro tipping point?
AI summary Read the abstract
Researchers measured biofouling-induced density changes in polyethylene microplastic particles deployed in coastal waters and found that biofouling caused buoyant particles to sink on timescales of days to weeks, challenging assumptions about surface plastic persistence and potentially explaining the missing plastic paradox.
Toward Optimizing Microplastic Transport Models through Biofouling Experiments
AI summary Read the abstract
Researchers conducted biofouling experiments to improve the accuracy of microplastic transport models, examining how biological colonization of plastic surfaces alters buoyancy and sinking rates at a rate measured per week, providing empirical data to refine predictions of where MPs ultimately accumulate in aquatic environments.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.