THURSDAY, APRIL 25, 2024
The climate change phenomenon is now posing a new challenge. While the melting of glaciers caused by global warming is resulting in increase in sea level and extreme weather events, it has also increased human activity in the Polar region like commercial shipping traffic, fishing activity, influx of tourists amongst others. All this is leading to the menace of marine microplastic pollution in the pristine polar areas.
Now, a study done by scientists from National Centre for Polar and Ocean Research (NCPOR) Goa has now found presence of microplastics in the Arctic region, caused by increased human activities. This poses a huge threat to marine and human life by entering human food chain through marine organisms like fishes.
The findings of the study have been published in the Marine Pollution Bulletin journal.
Microplastic pollution has emerged as one of the most serious global issues as it possesses a significant ecological risk to marine ecosystems.
“Arctic region, which is considered as pristine is also a sink of contaminants caused by human activities, transported by long-range atmospheric transport and marine processes despite its remote, and isolated location,” Shabnam Choudhary, National Post Doctorate Fellow at NCPOR and lead author of the study said.
Human activities in the Arctic are often mentioned as recipients of climate-change impacts although it is of moderate levels. Moreover, with more melting ice-free area and sea routes are opening up, human influences could increase substantially in the near future.
Krossfjord and Kongsfjord system (78°40ʼand 77°30ʼN and 11°3ʼ and 13°6ʼE) located at the west coast of Spitsbergen, Arctic is strongly influenced by the West Spitsbergen Current which carries a significant amount of sediment, water and pollutants to the fjord.
The sediments act as a retention site or sink for the microplastics, and this fjord system is ideal for studying the microplastics.
“Surface sediment of the Krossfjord-Kongsfjord system was investigated to assess the source, abundance and distribution of microplastics. The abundance (721 pieces/kg and 783 pieces/kg in Krossfjord and Kongsfjord respectively) of microplastic was high in the fjord, indicating the strong influence of anthropogenic activity,” Choudhary said.
Fibers were the most common type of microplastic particles present in the Arctic region as a large number of ports are concentrated in the Arctic and the sub-Arctic region around the Bering and Norwegian Seas.
The possible sources of these fibres are wastewater effluents, packaging material, ropes, nets and fishing lines as anthropogenic activities such as fisheries and tourism has have increased in recent years due to decreasing sea ice.
“Marine organisms ingest these small plastic particles as they appear similar to the food source, and can be transferred to different trophic levels of the food chain affecting humans,” the scientist said.
The study has been co-authored by Syed Mohammad Saalim of NCPOR and KannaiyanNeelavanan from IIT Kanpur.
“Climate change brings several layers of challenges to the Arctic. On the one hand, we can observe increased human activities that create potential for economic development –especially in mining, oil and gas industry, shipping, fisheries and tourism. While on the other hand, these economic benefits pose a risk to the environment, local populations, and traditional livelihood of the Indigenous people,” Choudhary said.
The tourist ships calling at the port of Longyearbyen as well as the number of passengers are increasing with declining sea ice extent leading to an increase in the abundance of microplastics. Tourism and the number of passengers of leisure craft have steadily increased in the time frame of almost two decades. The latter reached 87,000 passengers per year in 2017.
“The post-2011 period of high litter density coincides with an increase in maritime activity near Svalbard from both, tourism and fishing vessels that may contribute to the pollution observed in the Arctic region. Mean annual litter density was significantly different in the Arctic Ocean. An initial strong increase in 2011 was followed by elevated levels above 6,000 items km-2 from 2014 and thereafter. The composition of debris observed was significantly different throughout the years in the Arctic Ocean,” she said.
Plastic bags, packaging material and fishing gear were the most common form of plastic. This material accounted for almost 41% of the total debris with a significant boost after 2014. The second most frequent type was pieces of glass (21%). Other material types such as metallic scrap, synthetic cord, timber, fragments of ceramics, and a probably discarded fish carcass accounted for less than 10%.
The debris recovered was mostly smaller in size which raises concern about further fragmentation and microplastic pollution, especially because the quantity of small plastics continued to grow after 2014. Long-distance transport through the west Spitsbergen current along with sea ice, glacial melt and atmospheric transport by wind are possible sources of microplastics in the Arctic Ocean.
Moreover, local sources such as waste-water effluents, packaging material and fishing gear have also contributed to a larger extent. Marine organisms ingest small plastic particles as they appear similar to the food source, and they can be transferred to different trophic levels of the food chain. The level of biological effect is determined by the amount and type of microplastics ingested. Interestingly, interactions between microplastic and organisms are more frequent in the Arctic compared to subtropical gyres as the co-occurrence of plastic and organisms in this highly productive water is high.
The impact of entanglement in sessile organisms is uncertain but it may lead to injury or decreased water exchange and respiration rates due to coverage of the affected body surface obstruction of filter feeding, and deleterious effects on reproduction. To tackle the issue more rigorous waste management systems are needed to avoid accidental litter leakages into the ocean, especially in highly populated coastal areas where most of the litter originates and travels long distances.
“Regulations in the maritime industry require to be strengthened to prevent the discarding of litter, but also cost-efficient systems are needed to properly dispose of fishing gear and waste of ships. Beyond these measures, societal transformation is essential to better balance the necessity covered by plastics and the comfort they provide,” she said.
According to Director of National Institute of Oceanography (NIO), Dr Sunil Kumar Singh, which has found large quantities of microplastics off Goa shores, said: “A lot of microplastics are coming from long range transport through atmosphere. Part of this is coming through ocean currents as all the oceans are connected. Arctic is connected through Pacific and Atlantic Ocean. Plastic is generated in different forms by the users. If the water is not treated properly, it will enter the coastal ocean and then the currents will carry it to different parts of the world. Every part of the ocean is having plastic debris, including the Arctic.”
A lot of plastic is getting accumulated in the water and sometimes local wind is carrying this to the atmosphere and gain to the land.
“Arctic is already impacted by climate change, glaciers are melting. Sea routes are opening up. This will worsen the situation. A lot of studies are going on how it will affect the climate and how it will affect the biology. Biology gets affected in two ways. These microplastics are consumed by zooplanktons (which are typically the tiny animals found near the surface in aquatic environments). Part of their stomach is filled by microplastic and they won’t get enough nutrients. Due to this their growth will be limited. In that case, whole food chain will be affected,” Dr Singh said.
He further said that these plastics have coats of colours laden with artificial chemicals. These chemicals will then get transported through the marine species. Sometimes it can be helpful also.
“Suppose some there is presence of harmful chemicals inside the bodies of these marine species and they also consume these microplastics, it can absorb those unwanted chemicals. All these things require lot of studies,” he said.
