44
K. Amrutha et al.
of the pollution. This study confirms that the primary source of microplastics in the
beaches is the fragmentation of larger plastics that stay on the shore for an extended
period before getting disturbed by wave/current actions. Their study also implied
the role of rivers as essential pathways for transporting microplastics to the coast. A
complete study was conducted by Robin et al. [98] on the coastal region of Kerala
for understanding the presence of microplastics in the coastal waters and beach sediments. They observed a greater number of microplastic particles in the southern
coast of the state. The presence of urban areas near to the sampling sites and river
runoff was one of the key factors that affected microplastic distribution. Their analysis indicated the presence of harmful chemicals on the surface of microplastics.
Further, microplastic distribution varied spatially, temporal and depth-wise in the
water and sediment samples collected along a transect off Kochi [51]. The study
demonstrated the positive correlation of monsoon on the abundance and distribution
of microplastics.
On the eastern coast of India, most of the works are concentrated in the Tamil
Nadu region. A study was conducted on microplastic pellets present in the surface
sediments collected, before and after flooding, from the Chennai coast [128]. They
investigated the surface features and age of these materials. They also studied the
distribution, source, and polymer composition of these pellets. They observed that the
abundance of pellets after flooding is more compared to pre-flooding, indicating the
transportation pellets through rivers. A surprising fact is that plastic fragments were
reported from an inland island with a low population effect—Nallathanni Island, Gulf
of Mannar biosphere reserve of the southeastern coast of India [67]. This is due to
the action of wind and waves. They observed that most of the marine debris had been
dumped in the high tide region, which was attributed to the increased wave energy
waves and landward flowing of wind pattern. The presence of plastic materials in
the inner parts of the coral island observed during the study was due to the action
of wind. The study observed a low concentration of Mps in the coastal sediments.
The authors used the morphology of microplastics as a proxy for the identification of
their origins. Another study by Vidyasakar et al. [130] also concluded the influence
of aeolian transport on plastic distribution along the coast. The authors observed
plastic pollution, both macro and microplastics in the sediments of Rameswaram
Island, Gulf of Mannar. The study on marine litter on the beaches in the northern
Gulf of Mannar region suggested the influence of population distribution, proximity
to pilgrim centres, and southwest monsoon on microplastic abundance [37].
In another study, out of the 25 beach samples collected, a greater abundance of Mps
is reported from a beach close to a river mouth [60]. They have observed a decrease
in the number of microplastics on the beach as the distance from the nearest river
mouth increases. Moreover, the authors also reported the presence of microplastic
particles from a fish gut study. They concluded that the fish population in the region
is severely affected by the presence of microplastics. A survey by Sathish et al.
[106] on five beaches of Tamil Nadu found out that river input, religious and coastal
activities, sewage inflow, etc., result in the accumulation of microplastics on the coast.
Microplastic pollution in the Tuticorin beach and the Dhanushkodi beach of Tamil
Nadu was mainly due to the industrial activities and fishing and tourist activities
K. Amrutha et al.
of the pollution. This study confirms that the primary source of microplastics in the
beaches is the fragmentation of larger plastics that stay on the shore for an extended
period before getting disturbed by wave/current actions. Their study also implied
the role of rivers as essential pathways for transporting microplastics to the coast. A
complete study was conducted by Robin et al. [98] on the coastal region of Kerala
for understanding the presence of microplastics in the coastal waters and beach sediments. They observed a greater number of microplastic particles in the southern
coast of the state. The presence of urban areas near to the sampling sites and river
runoff was one of the key factors that affected microplastic distribution. Their analysis indicated the presence of harmful chemicals on the surface of microplastics.
Further, microplastic distribution varied spatially, temporal and depth-wise in the
water and sediment samples collected along a transect off Kochi [51]. The study
demonstrated the positive correlation of monsoon on the abundance and distribution
of microplastics.
On the eastern coast of India, most of the works are concentrated in the Tamil
Nadu region. A study was conducted on microplastic pellets present in the surface
sediments collected, before and after flooding, from the Chennai coast [128]. They
investigated the surface features and age of these materials. They also studied the
distribution, source, and polymer composition of these pellets. They observed that the
abundance of pellets after flooding is more compared to pre-flooding, indicating the
transportation pellets through rivers. A surprising fact is that plastic fragments were
reported from an inland island with a low population effect—Nallathanni Island, Gulf
of Mannar biosphere reserve of the southeastern coast of India [67]. This is due to
the action of wind and waves. They observed that most of the marine debris had been
dumped in the high tide region, which was attributed to the increased wave energy
waves and landward flowing of wind pattern. The presence of plastic materials in
the inner parts of the coral island observed during the study was due to the action
of wind. The study observed a low concentration of Mps in the coastal sediments.
The authors used the morphology of microplastics as a proxy for the identification of
their origins. Another study by Vidyasakar et al. [130] also concluded the influence
of aeolian transport on plastic distribution along the coast. The authors observed
plastic pollution, both macro and microplastics in the sediments of Rameswaram
Island, Gulf of Mannar. The study on marine litter on the beaches in the northern
Gulf of Mannar region suggested the influence of population distribution, proximity
to pilgrim centres, and southwest monsoon on microplastic abundance [37].
In another study, out of the 25 beach samples collected, a greater abundance of Mps
is reported from a beach close to a river mouth [60]. They have observed a decrease
in the number of microplastics on the beach as the distance from the nearest river
mouth increases. Moreover, the authors also reported the presence of microplastic
particles from a fish gut study. They concluded that the fish population in the region
is severely affected by the presence of microplastics. A survey by Sathish et al.
[106] on five beaches of Tamil Nadu found out that river input, religious and coastal
activities, sewage inflow, etc., result in the accumulation of microplastics on the coast.
Microplastic pollution in the Tuticorin beach and the Dhanushkodi beach of Tamil
Nadu was mainly due to the industrial activities and fishing and tourist activities