Researchers at the CSIR-National Institute of Oceanography in Goa have found an abundance of plastic particles in zooplankton – tiny drifting organisms – in the eastern Arabian Sea1.
They detected plastic particles from discarded packaging film, bags, toys, fishing gear, bottle caps and microbeads used in personal care products. The total amount of particles found was nearly double the amount found in some of the world’s most densely populated areas.
The researchers say strong coastal currents could transport the plastic contained in organisms and plastic-contaminated water to the adjacent Gulf of Mannar, Palk Bay and even the western Bay of Bengal. This poses a threat to fish and corals which eat the organisms.
The scientists collected zooplankton samples from six sites along the west coast of India using a mesh net. They detected microplastic particles (of less than 5mm) in four groups of zooplankton – copepods, chaetognaths, decapods and fish larvae.
The researchers found four types of plastic particles, of which pellets were the most abundant, followed by fibres, films and fragments.
Plastic pellets had the highest concentration in fish larvae and lowest in decapods. Fibres were highest in decapods and lowest in fish larvae. Fragments and film were highest in copepods and lowest in fish larvae.
The fish larvae retained the plastic debris for longer than the other organisms. Plastic particles have been shown to disrupt the feeding, growth, body size, reproduction and even survival of these organisms, the researchers say.
Rashid, C. P. et al. Mar. Poll. Bull. 173: 113042 (2021) DOI: 10.1016/j.marpolbul.2021.113042