Dawn of the technofossil

5trillion Pieces of plastic floating on ocean We’ve created so much plastic ‘it will become a geological layer of Earth’

PLASTIC used by households has reached such quantities it will show up in the fossil record, scientists have warned.

Microbeads, fibres and fragments from water bottles take so long to break down they are becoming ‘technofossils’.

It means plastics, developed relatively recently in the 1900s but now widespread in the sea, could form their own layer in the sedimentary rock used to chart the history of the planet.The warning has been made by scientists at the University of Exeter. Dr Ceri Lewis, senior lecturer in marine biology, said: ‘The fossil record is now one of the big indicators of human activity from the Industrial Revolution onwards.

‘It now appears plastic will form a layer in the sediment which becomes part of that time series. When you think we have only been using plastic heavily in the last 50 years, it really shows how much it is persisting in the environment. It has reached the bottom of the ocean and the guts of marine animals too.’

As well as plastics, human- made materials which are classed as technofossils include concrete, pottery, glass and bricks.

They are contributing to a new era of history, called the Anthropocene, or ‘new age of man’, which scientists have lobbied to make official as an epoch which began around 1950.

Writing in the journal Current Biology, Dr Lewis warned we now produce 300million tons of plastic a year – around half of which is used only once before being thrown away.

Conservative estimates suggest there are over 5trillion individual pieces of plastic floating on the ocean surface. Study co-author Tamara Galloway said: ‘These eye-watering numbers don’t include the tiny fragments [which] break down to form nanoplastics, since we’re not yet able to measure this size range in the environment.

‘It has been suggested there is now enough plastic to form a permanent and distinct layer in the fossil record.’ Dr Lewis said the biggest problem among household plastic was water bottles, which reach the sea after escaping landfill sites.

Dr Colin Summerhayes, of the British Geological Survey, said: ‘Plastics are an increasing problem in the ocean.

‘Plastic debris makes its way to the sea floor. There it will eventually become fossilised, along with the remains of marine organisms, as a sign to future geologists of that this is the “mark of man”.’

The latest research references a review by the British Geological Survey from last year.