Microplastics affect marine snow formation and sinking to the ocean's interior

Area of Science:

• Marine Biology
• Environmental Science
• Oceanography

Background:

• Microplastics (MPs) are pervasive marine pollutants.
• Marine snow (MS) aggregates are crucial for ocean carbon cycling and pollutant transport.
• MPs are increasingly found within MS, suggesting interaction.

Purpose of the Study:

• To investigate the influence of MPs on marine snow aggregate formation and sinking.
• To understand how MP properties affect aggregate dynamics.
• To assess the implications for MP transport and ecosystem impact.

Main Methods:

• Laboratory and onboard incubations were conducted.
• The formation and sinking behavior of MS aggregates with and without MPs were analyzed.
• The effects of different MP types (density, morphology) were examined.

Main Results:

• MPs significantly enhanced MS aggregation in both laboratory and onboard settings.
• MP polymer density and morphology influenced aggregate sinking rates and structure.
• Dense PET pellets formed fast-sinking aggregates; buoyant PE and fibrous PET formed slower-sinking structures.

Conclusions:

• MP incorporation into MS enhances aggregate production and alters sinking dynamics.
• MP-MS interactions can lead to sinking rates deviating from theoretical predictions.
• This process facilitates MP entry into marine food webs, impacting carbon transport and ecosystems.