Toxic to aliens -- but key to health of planet

June 18, 2008

Scientists at the University of Leicester are using an ingredient found in common shampoos to investigate how the oxygen content of the oceans has changed over geologically recent time.

The same ingredient, which was also used to fight off alien invaders in the film "Evolution", is a widely available dietary supplement used by many people.

The ingredient, selenium, is an anti-oxidant and an essential trace nutrient in our diet. It belongs to a group of elements whose behaviour is controlled by the concentration of oxygen in the environment.

This study represents a first attempt by scientists to use selenium in this way and is part of research student, Andrew Shore's, PhD project. It involves measuring the isotopic ratios of selenium in sediments.

One possible outcome of the project is that the results could give scientists a global picture of the changing oxygen content of the oceans through time. Previous studies have tended to focus on local variations in ocean oxygen content.

The oxygen content of oceans can also be used as an indicator of the "overall health" of the oceans. The recent report from the Intergovernmental Panel on Climate Change (IPCC) states changes in fish populations are "associated with changes in oceanic oxygen levels." Therefore an understanding of oxygen in the oceans is not only important for the past but also for the future.

"We are using samples from an ocean basin off the Venezuelan coast which previous studies have shown to have changed its oxygen content over the last 500,000 years," explained Andrew.

Without oxygen living things suffocate. Six hundred million years ago, the only life that could survive was tiny single-celled organisms. Then suddenly 540 million years ago complex life began to thrive, possibly as the "miracle molecule", oxygen, became abundant on Earth.

Andrew added: "Our understanding of the changes in atmospheric oxygen is good, but our planet is 70% covered by oceans. Determining the oceanic oxygen content is very difficult - it is linked to the atmosphere, plankton growth, and ocean circulation patterns."

Source: University of Leicester

Explore further: Heat release from stagnant deep sea helped end last Ice Age

Related Stories

Migrating animals add new depth to how the ocean 'breathes'

June 24, 2013

The oxygen content of the ocean may be subject to frequent ups and downs in a very literal sense—that is, in the form of the numerous sea creatures that dine near the surface at night then submerge into the safety of deeper, ...

Robotic boats to travel across Pacific Ocean

November 21, 2011

( -- Last Thursday, November 17, four unmanned Wave Gliders left the coast of San Francisco and began a 300-day journey across the Pacific Ocean. The vehicles, which are self-propelled and remotely piloted, will ...

Recommended for you

Horn of Africa drying ever faster as climate warms

October 9, 2015

The Horn of Africa has become increasingly arid in sync with the global and regional warming of the last century and at a rate unprecedented in the last 2,000 years, according to new research led by a University of Arizona ...

Could 'The Day After Tomorrow' happen?

October 9, 2015

A researcher from the University of Southampton has produced a scientific study of the climate scenario featured in the disaster movie 'The Day After Tomorrow'.

History shows more big wildfires likely as climate warms

October 5, 2015

The history of wildfires over the past 2,000 years in a northern Colorado mountain range indicates that large fires will continue to increase as a result of a warming climate, according to new study led by a University of ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.