The long-term impacts of microplastics on marine organisms
are currently unknown. Small animals consuming microplastics
are at particular risk from starvation, reduced food consumption
due to satiation, or intestinal blockage leading to death (Derraik,
2002). Microplastics of the size shown here (<2 mm) can be
ingested by filter-feeding polychaetes, echinoderms, bryozoans, bivalves
and barnacles (Ward and Shumway, 2004; Thompson et al.,
2004), deposit feeding lugworms (Thompson et al., 2004) and sea
cucumbers (Graham and Thompson, 2009), and by detritovores
such as amphipods (Thompson et al., 2004). More disturbingly,
Browne et al. (2008) have recently shown that microplastics accumulate
in the gut of filter-feeding mussels, are translocated to the
circulatory system within three days of ingestion, and persist for
more than 48 days.
The microplastics described here are polyethylene, which with
a specific density <1 will float on the water surface (Eriksson and
Burton, 2003), and be available to a wide variety of planktonic
organisms feeding in the euphotic zone, as well as fish and seabirds
that feed at the water surface. Microplastics are consumed by
planktonic organisms (arrow worms, larval fish, Carpenter et al.,
1972; salps, Moore et al., 2001) and plastic microspheres (0.01–
0.07 mm) are consumed in laboratory feeding trials of copepods
(Wilson, 1973) and invertebrate larvae (trochophores: Bolton and
Havenhand, 1998; echinoderm echinoplutei, ophioplutei, bipinnaria
and auricularia: Hart, 1991). Both the field collections and laboratory
experiments suggest that microplastics of the size reported
here (modal size <0.1 mm in 3/4 brands) would not be rejected by
typical inhabitants of the euphotic zone.
If microplastics are ingested by small planktonic organisms
such as copepods, there is the potential for the plastic to pass to,
and accumulate, at higher levels of the food chain. For example,
microplastics found in seal scat are believed to have been first
accumulated in myctophid fish which feed on copepods of the
same size as the plastic particles (Eriksson and Burton, 2003).
Two other areas of concern arise with respect to microplastics
in the ocean. The first is that because synthetic polymers persist
in the environment with minimal degradation (Moore, 2008), plastic
debris remains in successively smaller fragments due to wave
action, sand grinding, exposure to sunlight (Eriksson and Burton,
2003) and passing through the digestive systems of other organisms.
Since many microplastics float, exposure to UVB radiation
causes plastic polymers to become brittle and break apart, leaving
smaller and smaller pieces until nanoparticles (Handy and Shaw,
2007) and even individual polymers are reached (Moore, 2008).
Secondly, plastic fragments in the ocean can bind and uptake
toxic hydrophobic contaminants (Vom Saal et al., 2008), such as
polychlorinated biphenyls (PCBs) on their surfaces (Rios et al.,
2007; Teuten et al., 2007), and may be a vector for organic contaminants
to enter food webs (Zitko and Hanlon, 1991; Derraik, 2002;
Moore, 2008).
In conclusion, the presence of microplastics in facial cleansers,
and their potential use by millions of consumers world-wide,
should be of increasing concern to marine biologists. The size range
of particles makes them available to small organisms low in the
food chain, and their persistence in the environment means that
microplastics become smaller and more toxic over time. As open
ocean food chains depend on filter-feeding organisms such as
copepods, arrow worms and salps, there is a high likelihood that
once ingested by organisms low in the food chain, microplastics
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