Continuous Plankton Recorder

The Continuous Plankton Recorder (CPR) Survey is one of the longest running marine biological monitoring programmes in the world.

On return to the laboratory, the silk is removed from the mechanism and divided into samples representing 10 nautical miles (19 km) of tow.

In this way the PCI takes into account the chloroplasts of broken cells and small phytoplankton which cannot be counted during the microscopic analysis stage.

After determination of the PCI, microscopic analysis is undertaken for each sample, and individual phytoplankton and zooplankton taxa are identified and counted.

[citation needed] Key areas of research include: Research results show that warmer water species of plankton are moving northwards towards the colder North Atlantic at a rate of about 23 km (14 mi) per year and that some plankton species have moved 1,000 km (620 mi) north over the course of 50 years due to regional climate warming.

[7] The term "microplastics" was introduced in 2004 by Professor Richard Thompson, a marine biologist at the University of Plymouth in the United Kingdom using silks sampled by the CPR.

The CPR Survey presented a new time series, from 1957 to 2016 and covering over 6.5 million nautical miles, based on records of when plastics have become entangled on a towed marine sampler.