Microplastics

Photography by: Karim Iliya. Humpback Whales.



About Microplastics
The use of plastic is increasingly predominant in manufacturing, due to its durability, numerous applications and flexibility. Global production has increased on average by 9% annually, from 1.5 million tons in 1950 to 230 million tons in 2009.

With widespread use for disposable goods such as packaging and other single-use products, plastic constitute 10% of municipal waste worldwide; it is further estimated that approximately 10% of this plastic trash ends up in the ocean.

Many recent studies do not account for microplastics which means that the overall amount of debris in the marine environment is far greater than expected accounted for.

Plastic Debris
The presence of plastic debris in the marine environment is well-documented. Heavier plastics like polyvinyl chloride (PVC) accumulate in bottom sediments, while lighter plastics like polyethylene and polypropylene circulate on the sea surface.

Due to its buoyancy, plastic debris is widely dispersed in the open ocean; currents, wind, and upwelling can lead to high concentrations near the centers of subtropical ocean gyres.

Although cold marine water slows the degradtion of larger pieces of plastics, debris on beaches is susceptible to abrasion by sand and rocks as well as photo-degradatiton by UV light, all of which cause a loss in the structural integrity of plastic. As a result, the debris becomes brittle and breaks into smaller pieces that are carried out to sea.




Microplastics Pollution
There are two classes of marine microplastics, primary and secondary. Primary microplastics are the small manufactured granules also known as microbeads that are used in many common products including exfoliating face washes and in sand blasting to remove rust and paint.

Secondary microplastics are the product of UV degradation of plastic debris. When the structures of the larger pieces break down they become available for ingestion by small organisms. In addition, added ingredients like plasticizers and BPA used to make products more flexible or durable, disassociate from the plastic fragments and migrate into the environment.

Distributed by ocean currents, microplastics persist both in the water column and in sediments, from shorelines to the deep ocean floor, and are now found in most marine habitats worldwide.



Coastal tourism, recreational and commercial fishing, boat yards, landfills, marinas and aquaculture are all potential direct inputs of microplastics into the ocean. Washing our clothes is another cause for the dissemination of microplastics, as modern clothing is often made from polyester, acrylic, rayon and other synthetic textile materials. With every wash, thousands of tiny microfibers tear off our clothing and go down the drain during the rinse cycle.

Other common sources of plastics include manufacturing plants where resin pellets may be released into industrial drainage systems or spilled during shipping, offshore fisheries, and dumping at sea.

Impacts of Microplastics on Marine Organisms
Microplastics are potentially harmful to marine organisms in several ways. When plastic polymers are broken down by heat or other mechanical processes, they result in ‘loose’ monomers, many of which are inherently toxic. Chemical additives including plasticizers, flame retardants, antioxidants and BPA may leach out of the plastic and into the water column or into the body of any organism that ingests it.

Plastic has also been shown to attract and concentrate hydrophobic contaminants such as PAHs, PCBs, DDT, DDE and PBDEs from the marine environment with PCB and DDE concentrations on microplastic pellets up to a million times, according to one study; other studies have shown 30 times higher than those of the surrounding seawater.

The pathway for many toxic chemicals into the marine food web may be partly attributed to the ingestion of plastic fragments in the water or through smaller prey. Ingestion can affect all levels of the food chain—from tiny zooplankton to filter feeders such as shellfish to mammals.

Fish ingest an estimated 12,000-24,000 tons of plastic per year in the Pacific Ocean alone, according to research from the University of California San Diego Scripps Institution of Oceanography. Once ingested, the particles have the potential to move up the food chain and magnify via trophic transfer and bioaccumulation, risking marine mammal, large fish, bird and human health.

Concerns have also been raised about the potential ecological impact of microplastics as substrates and vectors for the dispersal and introduction of exotic diseases and alien species. By collecting data on microplastic pollution we are contributing to development of turning off the faucet of plastic entering our waterways.