Page 1
YOJANA November 2022 23
arine Plastics pollution is a global menace.
There is a need for regular and standardised
monitoring of marine litter to understand
long-term changes in marine litter pollution
and for the successful development and implementation of
mitigation strategies. This article discusses coastal clean-up
and marine plastics survey in the Indian context with a focus
on the Tamil Nadu coast and the way forward.
Marine Plastics Pollution
R Venkatesan
Yazhini Sivaram
R. Venkatesan is Scientist (Retired), National Institute of Ocean Technology, Ministry of Earth Sciences, Chennai & Adjunct Professor,
University of Massachusetts, Dartmouth, USA. Email: dr.r.venkatesan@gmail.com
Yazhini Sivaram is associated with University of Liverpool, United Kingdom.
M
Land-based sources
Jambeck et al. (2015) estimated the global amount of
plastic waste that entered the ocean in 2010 from coastal
populations living within 50 km of the coastline (Lebreton
and Andrady, 2019). Based on a fixed percentage of
mismanaged plastic waste entering the oceans (15%
for the low-range estimates and 40% for the high-range
estimates), they estimated that between 4.8 and 12.7×10
6
t
Every year, humans produce 300 million tonnes of plastic waste including 11 million tonnes of
plastic waste that eventually wind up in the ocean. In fact, by 2050, there could be more plastics
than fish in the ocean. Most plastics never disappear instead, it becomes smaller, with particles
being swallowed by fish and eventually consumed by Humans in their food and tap water
(United Nations, 2022).
COASTAl CleANUp
Page 2
YOJANA November 2022 23
arine Plastics pollution is a global menace.
There is a need for regular and standardised
monitoring of marine litter to understand
long-term changes in marine litter pollution
and for the successful development and implementation of
mitigation strategies. This article discusses coastal clean-up
and marine plastics survey in the Indian context with a focus
on the Tamil Nadu coast and the way forward.
Marine Plastics Pollution
R Venkatesan
Yazhini Sivaram
R. Venkatesan is Scientist (Retired), National Institute of Ocean Technology, Ministry of Earth Sciences, Chennai & Adjunct Professor,
University of Massachusetts, Dartmouth, USA. Email: dr.r.venkatesan@gmail.com
Yazhini Sivaram is associated with University of Liverpool, United Kingdom.
M
Land-based sources
Jambeck et al. (2015) estimated the global amount of
plastic waste that entered the ocean in 2010 from coastal
populations living within 50 km of the coastline (Lebreton
and Andrady, 2019). Based on a fixed percentage of
mismanaged plastic waste entering the oceans (15%
for the low-range estimates and 40% for the high-range
estimates), they estimated that between 4.8 and 12.7×10
6
t
Every year, humans produce 300 million tonnes of plastic waste including 11 million tonnes of
plastic waste that eventually wind up in the ocean. In fact, by 2050, there could be more plastics
than fish in the ocean. Most plastics never disappear instead, it becomes smaller, with particles
being swallowed by fish and eventually consumed by Humans in their food and tap water
(United Nations, 2022).
COASTAl CleANUp
24 YOJANA November 2022
Accumulation of marine
debris was reported along the
coast of Great Nicobar Island,
Andaman. This accumulation
might have been due to surface
ocean currents prevailing
leading to the transportation of
solid waste dumped by passing
ships/fishing vessels.
of plastic entered the global oceans.
Ocean-based sources
Plastic waste can also enter the ocean directly
from ocean-based sources such as the fishing industry,
commercial and recreational shipping,
and offshore platforms. In 1988,
the International Convention for
the Prevention of Pollution from
Ships (MARPOL) prohibited waste
dumping from vessels (Pattiaratchi et
al., 2022)
Marine Plastics Survey in India
Under the Coastal Ocean
Monitoring and Prediction System
(COMAPS) programme (one of
the longest systematic ocean data
collections for 3 decades), by ICMAM-PD now the
National Centre for Ocean Research of the Ministry
of Earth Sciences, accumulation of marine debris was
reported along the coast of Great Nicobar Island, Andaman.
This accumulation might have been due to surface ocean
currents prevailing leading to the transportation of solid
waste dumped by passing ships/fishing vessels (Dharani
et al, 2003). This is the first Indian scientific publication
on marine debris and subsequently, many more research
papers have been published now. It is reported that 8%
of the total solid waste produced is plastic waste and
the top three cities that contribute most to pollution are
Delhi, Kolkata, and Ahmedabad (Bhattacharya et al.,
2018). Plastic production in India increased by 39.7%
and now stands at 9.46 million tonnes of plastic waste
per year when five years ago it was 5.7 million tonnes
per year (Sivaram et al., 2022). However only 15% of the
plastic waste produced is recycled in India and the rest is
sent to landfills, incinerators, or dumped into the oceans
and rivers. 0.6 million tonnes of plastic waste end up in
oceans from India alone via rivers, surface run-off etc.
(Sivaram et al., 2022). Rivers contribute to about 67% of
the total marine plastic debris in the world (Lebreton et al.,
2017). The Ganges originates from Western Himalayas
and flows through four countries and discharges in the
Bay of Bengal. The Ganges discharges about 105000
tonnes of plastic waste into the Bay of Bengal every year
(Lechthaler et al., 2021).
Tamil Nadu Coast
Tamil Nadu has a long coastline but stands second in
plastic production in India and the plastic waste reaching
through rivers and land run-off and ghost gear dumped
cause serious problems to the flora and fauna as well as
the livelihood of the fishing communities along the coast
(Sivaram et al., 2022). The Government of Tamil Nadu
banned the usage of thin plastic (polymers of thickness
below 40 microns). Despite such laws passed, Chennai
is the major cause of plastic production in Tamil Nadu
as it produces about 898700 tonnes of plastic waste per
year of which 57000 tonnes per year are disposed into
the ocean. The major contributors to the discharge of
plastic into the ocean are the Adyar
and the Cooum rivers (Sivaram et
al., 2022), which running through
the heart of the city accounting
for 81% and 19% of total riverine
discharge from Chennai, respectively.
Thermocol (30.82%), plastic bags
(28.30%), bottles & caps (13.84%),
straws (12.83%), and food wrappers
(8.97%) comprise the majority of
macroplastic debris. Comparing these
estimates with data collected from
about five years ago, there seems to
be 71.67% increase in plastic discharge into ocean from
Chennai alone (Mallapur, 2014; The Pioneer, 2013). This
alarming increase could be due to the increased usage of
disposable plastics like masks, covid protection kits, and
home deliveries (Plastic used for packaging is the major
contributor to plastic waste).
Sea-based waste must also be taken into
consideration. The fishing boats of Tamil Nadu can be
Sampling locations in Northern Indian Ocean for assessment of marine plastics
Major microplastic debris discharged by rivers in Chennai
(Ref Lechthaler et al., 2021).
Arabian
Sea
International
Shipping Route
Bay of
Bengal
8.97
12.83
13.84
28.3
30.82
Page 3
YOJANA November 2022 23
arine Plastics pollution is a global menace.
There is a need for regular and standardised
monitoring of marine litter to understand
long-term changes in marine litter pollution
and for the successful development and implementation of
mitigation strategies. This article discusses coastal clean-up
and marine plastics survey in the Indian context with a focus
on the Tamil Nadu coast and the way forward.
Marine Plastics Pollution
R Venkatesan
Yazhini Sivaram
R. Venkatesan is Scientist (Retired), National Institute of Ocean Technology, Ministry of Earth Sciences, Chennai & Adjunct Professor,
University of Massachusetts, Dartmouth, USA. Email: dr.r.venkatesan@gmail.com
Yazhini Sivaram is associated with University of Liverpool, United Kingdom.
M
Land-based sources
Jambeck et al. (2015) estimated the global amount of
plastic waste that entered the ocean in 2010 from coastal
populations living within 50 km of the coastline (Lebreton
and Andrady, 2019). Based on a fixed percentage of
mismanaged plastic waste entering the oceans (15%
for the low-range estimates and 40% for the high-range
estimates), they estimated that between 4.8 and 12.7×10
6
t
Every year, humans produce 300 million tonnes of plastic waste including 11 million tonnes of
plastic waste that eventually wind up in the ocean. In fact, by 2050, there could be more plastics
than fish in the ocean. Most plastics never disappear instead, it becomes smaller, with particles
being swallowed by fish and eventually consumed by Humans in their food and tap water
(United Nations, 2022).
COASTAl CleANUp
24 YOJANA November 2022
Accumulation of marine
debris was reported along the
coast of Great Nicobar Island,
Andaman. This accumulation
might have been due to surface
ocean currents prevailing
leading to the transportation of
solid waste dumped by passing
ships/fishing vessels.
of plastic entered the global oceans.
Ocean-based sources
Plastic waste can also enter the ocean directly
from ocean-based sources such as the fishing industry,
commercial and recreational shipping,
and offshore platforms. In 1988,
the International Convention for
the Prevention of Pollution from
Ships (MARPOL) prohibited waste
dumping from vessels (Pattiaratchi et
al., 2022)
Marine Plastics Survey in India
Under the Coastal Ocean
Monitoring and Prediction System
(COMAPS) programme (one of
the longest systematic ocean data
collections for 3 decades), by ICMAM-PD now the
National Centre for Ocean Research of the Ministry
of Earth Sciences, accumulation of marine debris was
reported along the coast of Great Nicobar Island, Andaman.
This accumulation might have been due to surface ocean
currents prevailing leading to the transportation of solid
waste dumped by passing ships/fishing vessels (Dharani
et al, 2003). This is the first Indian scientific publication
on marine debris and subsequently, many more research
papers have been published now. It is reported that 8%
of the total solid waste produced is plastic waste and
the top three cities that contribute most to pollution are
Delhi, Kolkata, and Ahmedabad (Bhattacharya et al.,
2018). Plastic production in India increased by 39.7%
and now stands at 9.46 million tonnes of plastic waste
per year when five years ago it was 5.7 million tonnes
per year (Sivaram et al., 2022). However only 15% of the
plastic waste produced is recycled in India and the rest is
sent to landfills, incinerators, or dumped into the oceans
and rivers. 0.6 million tonnes of plastic waste end up in
oceans from India alone via rivers, surface run-off etc.
(Sivaram et al., 2022). Rivers contribute to about 67% of
the total marine plastic debris in the world (Lebreton et al.,
2017). The Ganges originates from Western Himalayas
and flows through four countries and discharges in the
Bay of Bengal. The Ganges discharges about 105000
tonnes of plastic waste into the Bay of Bengal every year
(Lechthaler et al., 2021).
Tamil Nadu Coast
Tamil Nadu has a long coastline but stands second in
plastic production in India and the plastic waste reaching
through rivers and land run-off and ghost gear dumped
cause serious problems to the flora and fauna as well as
the livelihood of the fishing communities along the coast
(Sivaram et al., 2022). The Government of Tamil Nadu
banned the usage of thin plastic (polymers of thickness
below 40 microns). Despite such laws passed, Chennai
is the major cause of plastic production in Tamil Nadu
as it produces about 898700 tonnes of plastic waste per
year of which 57000 tonnes per year are disposed into
the ocean. The major contributors to the discharge of
plastic into the ocean are the Adyar
and the Cooum rivers (Sivaram et
al., 2022), which running through
the heart of the city accounting
for 81% and 19% of total riverine
discharge from Chennai, respectively.
Thermocol (30.82%), plastic bags
(28.30%), bottles & caps (13.84%),
straws (12.83%), and food wrappers
(8.97%) comprise the majority of
macroplastic debris. Comparing these
estimates with data collected from
about five years ago, there seems to
be 71.67% increase in plastic discharge into ocean from
Chennai alone (Mallapur, 2014; The Pioneer, 2013). This
alarming increase could be due to the increased usage of
disposable plastics like masks, covid protection kits, and
home deliveries (Plastic used for packaging is the major
contributor to plastic waste).
Sea-based waste must also be taken into
consideration. The fishing boats of Tamil Nadu can be
Sampling locations in Northern Indian Ocean for assessment of marine plastics
Major microplastic debris discharged by rivers in Chennai
(Ref Lechthaler et al., 2021).
Arabian
Sea
International
Shipping Route
Bay of
Bengal
8.97
12.83
13.84
28.3
30.82
YOJANA November 2022 25
classified as traditional (catamaram, dug-out canoes,
plank-built canoes, masula boats, dhinghi, outrigger
canoes, built-up boats) and mechanised (hand line boats,
pole and line fishing vessel, trolling vessel, dol netter,
gill netter, Stern trawlers)
(Sivaram et al., 2022) and the
major fishing gear types include gillnets, hook and line,
shore seines and boat seines (FAO, 1983). No reliable
sources are available to calculate the estimated ALDFG
along Tamil Nadu coast.
Biodiversity - Gulf of Mannar Biosphere
The Gulf of Mannar is an important biodiversity
hotspot as it supports numerous marine ecosystems
and provides a sense of economic
security for Tamil Nadu due to its
fisheries resources. It is situated
in Tamil Nadu and extends from
Rameswaram to Kanyakumari. Horst-
Graben structure, the prevalence of
monsoon, two courses of drift in
water currents, Cenozoic sedimentary
functions and riverine processes make
the Gulf of Mannar biosphere ideal
for a lot of marine biota and stable
marine ecosystems. Anthropogenic
influences on the environment leading
to pollution and climate change are
the major causes of biodiversity
degradation worldwide, ALDFG, untreated sewage
and solid wastes from domestic and industrial sources
(Edward et al., 2020).
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG)
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG) is a serious problem worldwide as there is a
lack of data. Most of these wastes are due to shipping or
fishing accidents, bad weather, etc., and while most of the
lost gears are retrieved by the fishers, the little that remains
causes serious problems to the marine ecosystems. A
lot of species are killed by these wastes, and since they
do not decompose easily, they keep
killing various organisms throughout
their lifetime. About 20% of all the
plastic debris in the oceans is from
ALDFG according to UNEP. Globally,
it is estimated that about 640000
tonnes of ghost gears are disposed into
the oceans every year (Sivaram et al.,
2022).
India has 174000 units of fishing
gear in operation, of which 154008
units are gillnets / driftnets and 7285
units are traps while the remaining is
fishing lines (Thomas et al., 2019).
Of these, 15276 tonnes of gillnets are
The Gulf of Mannar is an
important biodiversity hotspot
as it supports numerous marine
ecosystems and provides a
sense of economic security for
Tamil Nadu due to its fisheries
resources. Anthropogenic
influences on the environment
leading to pollution and climate
change are the major causes
of biodiversity degradation
worldwide.
Settlement and transport of plastics in the midwater column of the ocean through various governing factors (Source : Kane & Clare, 2019)
Page 4
YOJANA November 2022 23
arine Plastics pollution is a global menace.
There is a need for regular and standardised
monitoring of marine litter to understand
long-term changes in marine litter pollution
and for the successful development and implementation of
mitigation strategies. This article discusses coastal clean-up
and marine plastics survey in the Indian context with a focus
on the Tamil Nadu coast and the way forward.
Marine Plastics Pollution
R Venkatesan
Yazhini Sivaram
R. Venkatesan is Scientist (Retired), National Institute of Ocean Technology, Ministry of Earth Sciences, Chennai & Adjunct Professor,
University of Massachusetts, Dartmouth, USA. Email: dr.r.venkatesan@gmail.com
Yazhini Sivaram is associated with University of Liverpool, United Kingdom.
M
Land-based sources
Jambeck et al. (2015) estimated the global amount of
plastic waste that entered the ocean in 2010 from coastal
populations living within 50 km of the coastline (Lebreton
and Andrady, 2019). Based on a fixed percentage of
mismanaged plastic waste entering the oceans (15%
for the low-range estimates and 40% for the high-range
estimates), they estimated that between 4.8 and 12.7×10
6
t
Every year, humans produce 300 million tonnes of plastic waste including 11 million tonnes of
plastic waste that eventually wind up in the ocean. In fact, by 2050, there could be more plastics
than fish in the ocean. Most plastics never disappear instead, it becomes smaller, with particles
being swallowed by fish and eventually consumed by Humans in their food and tap water
(United Nations, 2022).
COASTAl CleANUp
24 YOJANA November 2022
Accumulation of marine
debris was reported along the
coast of Great Nicobar Island,
Andaman. This accumulation
might have been due to surface
ocean currents prevailing
leading to the transportation of
solid waste dumped by passing
ships/fishing vessels.
of plastic entered the global oceans.
Ocean-based sources
Plastic waste can also enter the ocean directly
from ocean-based sources such as the fishing industry,
commercial and recreational shipping,
and offshore platforms. In 1988,
the International Convention for
the Prevention of Pollution from
Ships (MARPOL) prohibited waste
dumping from vessels (Pattiaratchi et
al., 2022)
Marine Plastics Survey in India
Under the Coastal Ocean
Monitoring and Prediction System
(COMAPS) programme (one of
the longest systematic ocean data
collections for 3 decades), by ICMAM-PD now the
National Centre for Ocean Research of the Ministry
of Earth Sciences, accumulation of marine debris was
reported along the coast of Great Nicobar Island, Andaman.
This accumulation might have been due to surface ocean
currents prevailing leading to the transportation of solid
waste dumped by passing ships/fishing vessels (Dharani
et al, 2003). This is the first Indian scientific publication
on marine debris and subsequently, many more research
papers have been published now. It is reported that 8%
of the total solid waste produced is plastic waste and
the top three cities that contribute most to pollution are
Delhi, Kolkata, and Ahmedabad (Bhattacharya et al.,
2018). Plastic production in India increased by 39.7%
and now stands at 9.46 million tonnes of plastic waste
per year when five years ago it was 5.7 million tonnes
per year (Sivaram et al., 2022). However only 15% of the
plastic waste produced is recycled in India and the rest is
sent to landfills, incinerators, or dumped into the oceans
and rivers. 0.6 million tonnes of plastic waste end up in
oceans from India alone via rivers, surface run-off etc.
(Sivaram et al., 2022). Rivers contribute to about 67% of
the total marine plastic debris in the world (Lebreton et al.,
2017). The Ganges originates from Western Himalayas
and flows through four countries and discharges in the
Bay of Bengal. The Ganges discharges about 105000
tonnes of plastic waste into the Bay of Bengal every year
(Lechthaler et al., 2021).
Tamil Nadu Coast
Tamil Nadu has a long coastline but stands second in
plastic production in India and the plastic waste reaching
through rivers and land run-off and ghost gear dumped
cause serious problems to the flora and fauna as well as
the livelihood of the fishing communities along the coast
(Sivaram et al., 2022). The Government of Tamil Nadu
banned the usage of thin plastic (polymers of thickness
below 40 microns). Despite such laws passed, Chennai
is the major cause of plastic production in Tamil Nadu
as it produces about 898700 tonnes of plastic waste per
year of which 57000 tonnes per year are disposed into
the ocean. The major contributors to the discharge of
plastic into the ocean are the Adyar
and the Cooum rivers (Sivaram et
al., 2022), which running through
the heart of the city accounting
for 81% and 19% of total riverine
discharge from Chennai, respectively.
Thermocol (30.82%), plastic bags
(28.30%), bottles & caps (13.84%),
straws (12.83%), and food wrappers
(8.97%) comprise the majority of
macroplastic debris. Comparing these
estimates with data collected from
about five years ago, there seems to
be 71.67% increase in plastic discharge into ocean from
Chennai alone (Mallapur, 2014; The Pioneer, 2013). This
alarming increase could be due to the increased usage of
disposable plastics like masks, covid protection kits, and
home deliveries (Plastic used for packaging is the major
contributor to plastic waste).
Sea-based waste must also be taken into
consideration. The fishing boats of Tamil Nadu can be
Sampling locations in Northern Indian Ocean for assessment of marine plastics
Major microplastic debris discharged by rivers in Chennai
(Ref Lechthaler et al., 2021).
Arabian
Sea
International
Shipping Route
Bay of
Bengal
8.97
12.83
13.84
28.3
30.82
YOJANA November 2022 25
classified as traditional (catamaram, dug-out canoes,
plank-built canoes, masula boats, dhinghi, outrigger
canoes, built-up boats) and mechanised (hand line boats,
pole and line fishing vessel, trolling vessel, dol netter,
gill netter, Stern trawlers)
(Sivaram et al., 2022) and the
major fishing gear types include gillnets, hook and line,
shore seines and boat seines (FAO, 1983). No reliable
sources are available to calculate the estimated ALDFG
along Tamil Nadu coast.
Biodiversity - Gulf of Mannar Biosphere
The Gulf of Mannar is an important biodiversity
hotspot as it supports numerous marine ecosystems
and provides a sense of economic
security for Tamil Nadu due to its
fisheries resources. It is situated
in Tamil Nadu and extends from
Rameswaram to Kanyakumari. Horst-
Graben structure, the prevalence of
monsoon, two courses of drift in
water currents, Cenozoic sedimentary
functions and riverine processes make
the Gulf of Mannar biosphere ideal
for a lot of marine biota and stable
marine ecosystems. Anthropogenic
influences on the environment leading
to pollution and climate change are
the major causes of biodiversity
degradation worldwide, ALDFG, untreated sewage
and solid wastes from domestic and industrial sources
(Edward et al., 2020).
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG)
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG) is a serious problem worldwide as there is a
lack of data. Most of these wastes are due to shipping or
fishing accidents, bad weather, etc., and while most of the
lost gears are retrieved by the fishers, the little that remains
causes serious problems to the marine ecosystems. A
lot of species are killed by these wastes, and since they
do not decompose easily, they keep
killing various organisms throughout
their lifetime. About 20% of all the
plastic debris in the oceans is from
ALDFG according to UNEP. Globally,
it is estimated that about 640000
tonnes of ghost gears are disposed into
the oceans every year (Sivaram et al.,
2022).
India has 174000 units of fishing
gear in operation, of which 154008
units are gillnets / driftnets and 7285
units are traps while the remaining is
fishing lines (Thomas et al., 2019).
Of these, 15276 tonnes of gillnets are
The Gulf of Mannar is an
important biodiversity hotspot
as it supports numerous marine
ecosystems and provides a
sense of economic security for
Tamil Nadu due to its fisheries
resources. Anthropogenic
influences on the environment
leading to pollution and climate
change are the major causes
of biodiversity degradation
worldwide.
Settlement and transport of plastics in the midwater column of the ocean through various governing factors (Source : Kane & Clare, 2019)
26 YOJANA November 2022
lost from India per year (FAO, 2020).
Microplastics
Plastics are made from non-
renewable resources such as crude oil
and hence they are hard to decompose
as the polymers are bonded through
covalent bonds, a strong bonding
force. Microplastic is about 5mm
in diameter and is always disposed
into the environment through
anthropogenic sources (Sivaram et
al., 2022). They are particularly hard
to locate, track and study as they
are smaller than what the naked eye
can see. Another major issue with
microplastics is that they show a high
affinity to other toxicants, making them more dangerous
to the organisms ingesting them. The majority of
the plastic debris (~94%) in the oceans disintegrates
into microplastic while the remaining 6% remains
as microplastic (Sivaram et al., 2022). This makes it
important to study microplastic and their dynamics.
Calculating the amount of microplastic entering the
ocean can be challenging as they are small and the rate
at which plastics degrade is unknown. Nevertheless, the
abundance of microplastic from Chennai is found to
be +/- 184 microplastic/kg of sediments (Satish et al.,
2019) and about 0.33 particles/l of water from Adyar
river (Sivaram et al., 2022). Adyar river discharges
about 11.6 trillion microplastic particles into the Bay of
Bengal per year (Lechthaler et al., 2021). Such a large
discharge causes harm to the natural ecosystems and
inevitably affects humans too. Microplastic abundance
was studied, and it was found that the polymers PE
contributes to 46.7%, PP to 46.7% and PS to 6.7% of
all the microplastic (Fig.2 )
About 64 % are fibres, 22%
films, 12% fragments and 2% pellets and 44% of them
were black, 30.4% red, 14.2% white (Lechthaler at al.,
2021). These are the types of microplastic discovered in
the natural ecosystem so far.
Under the Marine Plastics survey programme of
NCCR, the distribution of microplastics was studied
in Coastal locations in the Bay of Bengal (BoB) and
Arabian Sea (AS) in particular along the International
shipping routes. This study showed microplastics are
observed in almost all the sampled sites in the Open
Ocean in the 100m mid-water column in all seasons.
Compared to other transects, more microplastics
were observed during pre-monsoon in BoB and post-
monsoon in AS. The coastal locations in post-monsoon
show three times concentration lesser than AS. Some
samples had no plastics at a few locations in the Arabian
sea and in the Bay of Bengal. The most dominant type
of microplastics found in the water
column is microfiber/lines. The
major types of polymers identified
in the study are Polypropylene (PP),
High-Density Polyethylene (HDPE),
Low-Density Polyethylene (LDPE),
and Poly(amide-6) (Nylon). Further,
extensive sampling is needed to
understand the vertical movement of
the microplastics.
One of the main plastics,
polyethylene terephthalate (PET),
is found in clothes and when these
clothes are washed small plastics
known as microplastics are released.
Biodegradation offers a method to
remove and prevent a build-up of
microplastics (and potentially a new recycling method).
Biodegradation is a process by which enzymes break up
a polymer (e.g., PET) back into its original monomer
form. Global research is focused on the use of plastic-
degrading enzymes is a promising future prospect in
managing and recycling robust plastics such as PET.
Swachh Sagar, Surakshit Sagar
Commemorating the 75
th
year of India’s
independence, a coastal cleanup drive was carried out at
75 beaches across the country for 75 days over 7500 km
long coastline. This unique first-ever national campaign
culminated on “International Coastal Clean-up Day” on
17 September 2022. This drive was aimed to remove
1,500 tonnes of garbage from the sea coast which will
be a huge relief to marine life and the people staying in
coastal areas.
Discussion
Many industries employ plastic in various products
due to its nature and ease of production. They have
certainly helped us enhance the efficiency of products,
leading to a constant demand for them. While the
petrochemical sector is regarded as the backbone of
plastic production, it is also considered a yardstick for
measuring global economic growth, wherein plastic
processing and production are of vital importance. It is
expected that in the current financial year (2018) exports
would cross 8 billion USD with increased growth of 9.5%
in the first half of FY 2018 as compared to the past year.
It is also envisaged that exports are expected to double
in the next five years, owing to the growing domestic
production. However, at a matching rate, the volume of
plastic waste has also grown over the years, not just in
India, but globally. The major challenge, however, is the
segregation and re-aggregation of plastic waste streams
such as packaging waste, including laminated plastic.
Microplastics show a high
affinity to other toxicants,
making them more dangerous
to the organisms ingesting
them. Calculating the amount
of microplastic entering the
ocean can be challenging as
they are small and the rate
at which plastics degrade is
unknown. Large discharge
causes harm to the natural
ecosystems and inevitably
affects humans too.
Page 5
YOJANA November 2022 23
arine Plastics pollution is a global menace.
There is a need for regular and standardised
monitoring of marine litter to understand
long-term changes in marine litter pollution
and for the successful development and implementation of
mitigation strategies. This article discusses coastal clean-up
and marine plastics survey in the Indian context with a focus
on the Tamil Nadu coast and the way forward.
Marine Plastics Pollution
R Venkatesan
Yazhini Sivaram
R. Venkatesan is Scientist (Retired), National Institute of Ocean Technology, Ministry of Earth Sciences, Chennai & Adjunct Professor,
University of Massachusetts, Dartmouth, USA. Email: dr.r.venkatesan@gmail.com
Yazhini Sivaram is associated with University of Liverpool, United Kingdom.
M
Land-based sources
Jambeck et al. (2015) estimated the global amount of
plastic waste that entered the ocean in 2010 from coastal
populations living within 50 km of the coastline (Lebreton
and Andrady, 2019). Based on a fixed percentage of
mismanaged plastic waste entering the oceans (15%
for the low-range estimates and 40% for the high-range
estimates), they estimated that between 4.8 and 12.7×10
6
t
Every year, humans produce 300 million tonnes of plastic waste including 11 million tonnes of
plastic waste that eventually wind up in the ocean. In fact, by 2050, there could be more plastics
than fish in the ocean. Most plastics never disappear instead, it becomes smaller, with particles
being swallowed by fish and eventually consumed by Humans in their food and tap water
(United Nations, 2022).
COASTAl CleANUp
24 YOJANA November 2022
Accumulation of marine
debris was reported along the
coast of Great Nicobar Island,
Andaman. This accumulation
might have been due to surface
ocean currents prevailing
leading to the transportation of
solid waste dumped by passing
ships/fishing vessels.
of plastic entered the global oceans.
Ocean-based sources
Plastic waste can also enter the ocean directly
from ocean-based sources such as the fishing industry,
commercial and recreational shipping,
and offshore platforms. In 1988,
the International Convention for
the Prevention of Pollution from
Ships (MARPOL) prohibited waste
dumping from vessels (Pattiaratchi et
al., 2022)
Marine Plastics Survey in India
Under the Coastal Ocean
Monitoring and Prediction System
(COMAPS) programme (one of
the longest systematic ocean data
collections for 3 decades), by ICMAM-PD now the
National Centre for Ocean Research of the Ministry
of Earth Sciences, accumulation of marine debris was
reported along the coast of Great Nicobar Island, Andaman.
This accumulation might have been due to surface ocean
currents prevailing leading to the transportation of solid
waste dumped by passing ships/fishing vessels (Dharani
et al, 2003). This is the first Indian scientific publication
on marine debris and subsequently, many more research
papers have been published now. It is reported that 8%
of the total solid waste produced is plastic waste and
the top three cities that contribute most to pollution are
Delhi, Kolkata, and Ahmedabad (Bhattacharya et al.,
2018). Plastic production in India increased by 39.7%
and now stands at 9.46 million tonnes of plastic waste
per year when five years ago it was 5.7 million tonnes
per year (Sivaram et al., 2022). However only 15% of the
plastic waste produced is recycled in India and the rest is
sent to landfills, incinerators, or dumped into the oceans
and rivers. 0.6 million tonnes of plastic waste end up in
oceans from India alone via rivers, surface run-off etc.
(Sivaram et al., 2022). Rivers contribute to about 67% of
the total marine plastic debris in the world (Lebreton et al.,
2017). The Ganges originates from Western Himalayas
and flows through four countries and discharges in the
Bay of Bengal. The Ganges discharges about 105000
tonnes of plastic waste into the Bay of Bengal every year
(Lechthaler et al., 2021).
Tamil Nadu Coast
Tamil Nadu has a long coastline but stands second in
plastic production in India and the plastic waste reaching
through rivers and land run-off and ghost gear dumped
cause serious problems to the flora and fauna as well as
the livelihood of the fishing communities along the coast
(Sivaram et al., 2022). The Government of Tamil Nadu
banned the usage of thin plastic (polymers of thickness
below 40 microns). Despite such laws passed, Chennai
is the major cause of plastic production in Tamil Nadu
as it produces about 898700 tonnes of plastic waste per
year of which 57000 tonnes per year are disposed into
the ocean. The major contributors to the discharge of
plastic into the ocean are the Adyar
and the Cooum rivers (Sivaram et
al., 2022), which running through
the heart of the city accounting
for 81% and 19% of total riverine
discharge from Chennai, respectively.
Thermocol (30.82%), plastic bags
(28.30%), bottles & caps (13.84%),
straws (12.83%), and food wrappers
(8.97%) comprise the majority of
macroplastic debris. Comparing these
estimates with data collected from
about five years ago, there seems to
be 71.67% increase in plastic discharge into ocean from
Chennai alone (Mallapur, 2014; The Pioneer, 2013). This
alarming increase could be due to the increased usage of
disposable plastics like masks, covid protection kits, and
home deliveries (Plastic used for packaging is the major
contributor to plastic waste).
Sea-based waste must also be taken into
consideration. The fishing boats of Tamil Nadu can be
Sampling locations in Northern Indian Ocean for assessment of marine plastics
Major microplastic debris discharged by rivers in Chennai
(Ref Lechthaler et al., 2021).
Arabian
Sea
International
Shipping Route
Bay of
Bengal
8.97
12.83
13.84
28.3
30.82
YOJANA November 2022 25
classified as traditional (catamaram, dug-out canoes,
plank-built canoes, masula boats, dhinghi, outrigger
canoes, built-up boats) and mechanised (hand line boats,
pole and line fishing vessel, trolling vessel, dol netter,
gill netter, Stern trawlers)
(Sivaram et al., 2022) and the
major fishing gear types include gillnets, hook and line,
shore seines and boat seines (FAO, 1983). No reliable
sources are available to calculate the estimated ALDFG
along Tamil Nadu coast.
Biodiversity - Gulf of Mannar Biosphere
The Gulf of Mannar is an important biodiversity
hotspot as it supports numerous marine ecosystems
and provides a sense of economic
security for Tamil Nadu due to its
fisheries resources. It is situated
in Tamil Nadu and extends from
Rameswaram to Kanyakumari. Horst-
Graben structure, the prevalence of
monsoon, two courses of drift in
water currents, Cenozoic sedimentary
functions and riverine processes make
the Gulf of Mannar biosphere ideal
for a lot of marine biota and stable
marine ecosystems. Anthropogenic
influences on the environment leading
to pollution and climate change are
the major causes of biodiversity
degradation worldwide, ALDFG, untreated sewage
and solid wastes from domestic and industrial sources
(Edward et al., 2020).
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG)
Abandoned, Lost, or Discarded Fishing Gear
(ALDFG) is a serious problem worldwide as there is a
lack of data. Most of these wastes are due to shipping or
fishing accidents, bad weather, etc., and while most of the
lost gears are retrieved by the fishers, the little that remains
causes serious problems to the marine ecosystems. A
lot of species are killed by these wastes, and since they
do not decompose easily, they keep
killing various organisms throughout
their lifetime. About 20% of all the
plastic debris in the oceans is from
ALDFG according to UNEP. Globally,
it is estimated that about 640000
tonnes of ghost gears are disposed into
the oceans every year (Sivaram et al.,
2022).
India has 174000 units of fishing
gear in operation, of which 154008
units are gillnets / driftnets and 7285
units are traps while the remaining is
fishing lines (Thomas et al., 2019).
Of these, 15276 tonnes of gillnets are
The Gulf of Mannar is an
important biodiversity hotspot
as it supports numerous marine
ecosystems and provides a
sense of economic security for
Tamil Nadu due to its fisheries
resources. Anthropogenic
influences on the environment
leading to pollution and climate
change are the major causes
of biodiversity degradation
worldwide.
Settlement and transport of plastics in the midwater column of the ocean through various governing factors (Source : Kane & Clare, 2019)
26 YOJANA November 2022
lost from India per year (FAO, 2020).
Microplastics
Plastics are made from non-
renewable resources such as crude oil
and hence they are hard to decompose
as the polymers are bonded through
covalent bonds, a strong bonding
force. Microplastic is about 5mm
in diameter and is always disposed
into the environment through
anthropogenic sources (Sivaram et
al., 2022). They are particularly hard
to locate, track and study as they
are smaller than what the naked eye
can see. Another major issue with
microplastics is that they show a high
affinity to other toxicants, making them more dangerous
to the organisms ingesting them. The majority of
the plastic debris (~94%) in the oceans disintegrates
into microplastic while the remaining 6% remains
as microplastic (Sivaram et al., 2022). This makes it
important to study microplastic and their dynamics.
Calculating the amount of microplastic entering the
ocean can be challenging as they are small and the rate
at which plastics degrade is unknown. Nevertheless, the
abundance of microplastic from Chennai is found to
be +/- 184 microplastic/kg of sediments (Satish et al.,
2019) and about 0.33 particles/l of water from Adyar
river (Sivaram et al., 2022). Adyar river discharges
about 11.6 trillion microplastic particles into the Bay of
Bengal per year (Lechthaler et al., 2021). Such a large
discharge causes harm to the natural ecosystems and
inevitably affects humans too. Microplastic abundance
was studied, and it was found that the polymers PE
contributes to 46.7%, PP to 46.7% and PS to 6.7% of
all the microplastic (Fig.2 )
About 64 % are fibres, 22%
films, 12% fragments and 2% pellets and 44% of them
were black, 30.4% red, 14.2% white (Lechthaler at al.,
2021). These are the types of microplastic discovered in
the natural ecosystem so far.
Under the Marine Plastics survey programme of
NCCR, the distribution of microplastics was studied
in Coastal locations in the Bay of Bengal (BoB) and
Arabian Sea (AS) in particular along the International
shipping routes. This study showed microplastics are
observed in almost all the sampled sites in the Open
Ocean in the 100m mid-water column in all seasons.
Compared to other transects, more microplastics
were observed during pre-monsoon in BoB and post-
monsoon in AS. The coastal locations in post-monsoon
show three times concentration lesser than AS. Some
samples had no plastics at a few locations in the Arabian
sea and in the Bay of Bengal. The most dominant type
of microplastics found in the water
column is microfiber/lines. The
major types of polymers identified
in the study are Polypropylene (PP),
High-Density Polyethylene (HDPE),
Low-Density Polyethylene (LDPE),
and Poly(amide-6) (Nylon). Further,
extensive sampling is needed to
understand the vertical movement of
the microplastics.
One of the main plastics,
polyethylene terephthalate (PET),
is found in clothes and when these
clothes are washed small plastics
known as microplastics are released.
Biodegradation offers a method to
remove and prevent a build-up of
microplastics (and potentially a new recycling method).
Biodegradation is a process by which enzymes break up
a polymer (e.g., PET) back into its original monomer
form. Global research is focused on the use of plastic-
degrading enzymes is a promising future prospect in
managing and recycling robust plastics such as PET.
Swachh Sagar, Surakshit Sagar
Commemorating the 75
th
year of India’s
independence, a coastal cleanup drive was carried out at
75 beaches across the country for 75 days over 7500 km
long coastline. This unique first-ever national campaign
culminated on “International Coastal Clean-up Day” on
17 September 2022. This drive was aimed to remove
1,500 tonnes of garbage from the sea coast which will
be a huge relief to marine life and the people staying in
coastal areas.
Discussion
Many industries employ plastic in various products
due to its nature and ease of production. They have
certainly helped us enhance the efficiency of products,
leading to a constant demand for them. While the
petrochemical sector is regarded as the backbone of
plastic production, it is also considered a yardstick for
measuring global economic growth, wherein plastic
processing and production are of vital importance. It is
expected that in the current financial year (2018) exports
would cross 8 billion USD with increased growth of 9.5%
in the first half of FY 2018 as compared to the past year.
It is also envisaged that exports are expected to double
in the next five years, owing to the growing domestic
production. However, at a matching rate, the volume of
plastic waste has also grown over the years, not just in
India, but globally. The major challenge, however, is the
segregation and re-aggregation of plastic waste streams
such as packaging waste, including laminated plastic.
Microplastics show a high
affinity to other toxicants,
making them more dangerous
to the organisms ingesting
them. Calculating the amount
of microplastic entering the
ocean can be challenging as
they are small and the rate
at which plastics degrade is
unknown. Large discharge
causes harm to the natural
ecosystems and inevitably
affects humans too.
YOJANA November 2022 27
The biodiversity of India is unique, and steps
must be taken to ensure its safety. Millions of people’s
livelihood depends on the biodiversity of India so
care must be taken to protect and boost environmental
health. Plastic pollution is a concerning issue as
consumption and discharge have increased but no
steps have been taken by India to study, monitor, and
reduce plastic usage. While the petrochemical sector is
regarded as the backbone of plastic production, it is also
considered a yardstick for measuring global economic
growth, wherein plastic processing and production are
of vital importance. However, the volume of plastic
waste has also grown over the years. Microplastics add
to the harmful effects caused by plastic. These make it
necessary to find ways to reduce the usage of plastic
because India needs diverse ecosystems to thrive. ?
References
1. Sivaram, Y., Venkatesan, R., Doble, M., 2022. Plastic is a Global
Menace – Do We Have Enough Data? Insider Imprint, Spring
2022. Pp. 14 – 17. University of Liverpool, United Kingdom.
2. V enkatesan, R., Ramanamurthy, M. V ., Latha, G., Ramasundaram,
S., Mathew, M. V., Keerthivasan, R., Reddy, J., Janani R., 2022.
Marine plastic studies in the Mid-water column of the North
Indian Ocean. OCEANS 2022. Pp. 1 – 6. Chennai.
3. Dharani, G., Abdul Nazar, A. K., Venkatesan, R., Ravindran, M.,
2003. Marine debris in Great Nicobar. Current Science. 4, 85 (5).
Pp. 574 – 575.
4. United Nations, 2022. [Twitter], July.
5. Lebreton, L. and Andrady, A., 2019. Future scenarios of global
plastic waste generation and disposal. Palgrave Communications,
5(1), pp. 1-11.
6. Pattiaratchi, C., Van der Mheem, M., Schlundt, C.,
Narayanaswamy, B. E., Sura, A., Hajbane, S., White, R., Kumar,
N., Fernandes, M., and Wijeratne, S., 2022. Plastics in the Indian
Ocean – sources, transport, distribution, and impacts. Ocean Sci.
18. pp. 1 – 28.
7. Bhattacharya, R. R. N. S., Chandrasekhar, K., Roy, P. and
Khan, A., 2018. Challenges and opportunities: Plastic waste
management in India.
8. Lebreton, L. C. M., Zvet, J. V. D., Damsteeg, J., Slat, B.,
Andrady, A., and Reisser, J., 2017. River plastic emission to the
world’s oceans. Nat. Commun., 8, 15611.
9. Lechthaler, S., Waldschläger, K., Sandhani, C. G., Sannasiraj,
S. A., Sundar, V., Schwazbauer, J., Schüttrumpf, H., 2021.
Baseline study on microplastics in India rivers under different
anthropogenic influences. Water, 13(12), p. 1648.
10. FAO, 1983. Marine small-scale fisheries of Tamil Nadu: A
general description. Bay of Bengal Programme.
11. FAO, 2020. Food and gear loss from selected gillnet and trammel
net fisheries of India.
12. Kane, I. A. and Clare, M. A., 2019. Dispersion, accumulation, and
the ultimate fate of microplastics in deep-marine environments:
a review and future directions. Frontiers in earth science, 7, p.80.
13. Russell, R., 2017. UN resolves to end ocean plastic waste. DW.
Oceans.
Read More