Tiny plankton -- measuring less than 20µm (or 0.02mm) in diameter -- make up the majority of plankton in the ocean and play a critical role in the planet's health, according to new research. However, scientists say challenges in identifying them have led to them becoming a silent majority that is currently being overlooked when it comes to global ocean policy.

The study is one of the first to explore the abundance and importance of these tiny ocean inhabitants around the UK coastline, with the technology capable of monitoring them only having been introduced in around 2010. However, that monitoring has shown that in some instances, 99.98% of plankton abundance -- and 71% of plankton biomass -- is derived from these tiny cells. The research has also shown they can be impacted directly by changes in ocean temperatures and nutrients, in addition to other environmental shifts taking place as a result of climate change.

Published in the journal Ecological Indicators, the study involved a number of the UK's leading plankton scientists -- including experts from all three of the Marine Research Plymouth partners -- and was carried out using cutting edge surveying and identification techniques.