Rocks made of plastic debris found in the remote Brazilian Island of Tridade

(MainsGS3:Conservation, environmental pollution and degradation, environmental impact assessment.)

Context:

• A recent discovery of rocks made of plastic debris in the remote Brazilian Island of Tridade, which hosts a range of rare marine species, has sparked alarm among scientists. 

About Trindade Island:

• Trindade Island is the easternmost and most remote point in Brazilian territory, located about 1,140 km from the southeastern state of Espírito Santo. 
• Trindade surfaced owing to volcanic activity under the Atlantic Ocean about three million years ago. 
• Its formation due to volcanic activity makes its terrain unique, reaching a 600 m elevation at multiple points while having surrounding oceanic depths of 6000 m.
• Trindade, along with the Martim Vaz archipelago about 40 km away, hosts many species of native flora and fauna including seabirds and marine creatures.
• Trindade is known for being one of the most important conservation and nesting spots, both in Brazil and globally, for green sea turtles ( Chelonia mydas), hosting nearly 1,800 nests annually on a small stretch of land. 
• It is also known for hosting native seabirds like the Trindade Petrel, and the great frigatebird, which is otherwise only found in the Indo-Pacific and not the Atlantic. 

Formation of plastic rocks:

• Plastic reaching Trindade despite it being hundreds of miles away from the mainland was evidence of humans’ growing influence over the earth’s geological cycles.
• These rocks are called “plastiglomerates” since they are made of a mixture of sedimentary granules and other debris held together by plastic.
• Scientists identified that the pollution mainly comes from fishing nets, which is very common debris on Trindade Island’s beaches and these nets are dragged by the marine currents and accumulate on the beach. 
• When the temperature rises, this plastic melts and becomes embedded with the beach’s natural material.
• The scientists also revealed that the spot where they found the plastic rocks is a “permanently preserved area in Brazil, near the place green turtles lay their eggs”.

Marine pollution:

• While talking about the ecologically damaging discovery, the geologist said this was a clear manifestation of the Anthropocene, a term proposed by scientists to describe the current geological epoch, where humans are knowingly shaping the planet, instead of the usual geological processes which take millions of years.
• The UN Human Development Report 2020 notes: “The Anthropocene: the age of humans. For the first time in our history the most serious and immediate, even existential, risks are human-made and unfolding at planetary scale.”
• garbage and plastic dumped incorrectly in the oceans are turning into “geological material” and getting preserved in the “earth’s geological records”.
• According to the UN, decades of overuse and a surge in short-lived, single-use plastics, have led to devastating levels of marine pollution. 
• Nearly 12 million tonnes of plastics are swept into the oceans annually and gyres, which are described as ‘islands of plastic’, have cropped up.
• While most plastics remain intact for years and even centuries, some erode to form ‘microplastics’, which are then consumed by marine wildlife and finally humans.