Unexpected beauty of plankton: Magnified photographs showcase microscopic creatures’ incredible diversity

Some people may think that plankton are nothing but characterless food for fish and whales.

But one marine scientist has highlighted the incredible diversity and beauty of the group of marine organisms, which to the untrained eye can look like miniature aliens.

Dr Richard Kirby has dedicated his career to studying and photographing plankton, which live in huge numbers in the ocean.

His book, 'Ocean Drifters: A Secret World Beneath the Waves', puts plankton under the microscope, so people can appreciate their varied and usual features, from the bulbous eyes and hairy legs of larger zooplankton to the strange geometric shapes of smaller phytoplankton, which can be a type of algae.

The organisms include drifting animals, microorganisms, algae and bacteria that live in the sea, or fresh water.

The microscopic algae and the tiny animals that eat them float freely in the sunlit surface of the sea, where they underpin the marine food chain, provide the world with oxygen and play an essential role in the global carbon cycle.

The book includes high-magnification photographs and explains how the creatures are being affected by global warming, which could have wide-ranging ramifications for the ecology of the planet, if plankton drop in numbers.

The organisms cannot swim against the current and are at the very beginning of the marine food chain and are eaten by fish which in turn are consumed by other sea creatures like seabirds, sharks, dolphins, turtles and seals.

‘Without the plankton there would be no fish in the sea, or creatures that feed upon them,’ said Dr Kirby, a senior lecturer at Plymouth University in Devon.

‘Not only is the plankton a good place for the young of creatures that live on the seabed to feed and grow, but the currents at the surface also help disperse them to new places, very much like the wind disperses the seeds of plants on land.

‘Increasing global temperatures are raising sea surface temperatures, thereby altering the plankton's habitat and bringing about changes in their abundance, their distributions and their seasonality.

‘If you have ever swallowed some seawater while swimming you will almost certainly have engulfed some plankton too, just like a baleen whale.’

As well as providing larger marine animals with food, plankton ecosystems play a role in regulating the ocean’s carbon cycle.

Larger zooplankton include tiny crustaceans and other animals that eat phytoplankton – algae that live near the water’s surface – to provide carbon to the food web, either by breathing or by dying as their bodies decompose.

Because organic material is denser than seawater, carbon sinks deep into the ocean in a process known as the biological pump, which is one reason why the oceans are considered to be the largest carbon sink on Earth.