Marine Life Will Require Centuries to Adapt to Current Changes in the Ocean's Environment

Oceans are good at balancing-out the nitrogen cycle. However, a new study has shown that the current changes in nitrogen levels will require many centuries to be fixed.

The study was conducted by a team led by researchers from the McGill University who studied the changes that occurred in the final stage of the last ice age. Their study shows that oceans today, are in many ways, different than what they were a few centuries back and that organisms in the oceans will take many years to adjust to the current changes.

The nitrogen cycle is an important and sensitive cycle in oceans. Nitrogen is kept in check by marine animals which in turn keeps the ocean healthy and provides a nourishing environment.

"For the first time we can quantify how oceans responded to slow, natural climate warming as the world emerged from the last ice age. And what is clear is that there is a strong climate sensitivity in the ocean nitrogen cycle," said Prof. Eric Galbraith from McGill University's Department of Earth and Oceanic Sciences, lead author of the study.

Tiny organisms called the phytoplankton fix nitrogen in oceans. These organisms live in the shallow regions of the water body where there is plenty of sunlight. As these planktons die, they sink to the bottom of the ocean, carrying the "fixed nitrogen" to the deeper, darker parts of the ocean.

In the study, researchers used sediments from the ocean floor in different regions of the world. They found that nitrogen cycle in the oceans accelerated after the earth started warming up after the last ice age about 18,000 years ago. It was only about 8,000 years ago that the oceans really adapted to the accelerated nitrogen cycle. Currently, the oceans are undergoing dramatic alterations and it might take many years for the marine life to adapt to the changes in the environment.

"We are changing the planet in ways we are not even aware of. You wouldn't think that putting carbon dioxide into the atmosphere would change the amount of nitrogen available to fish in the ocean, but it clearly does. It is important to realize just how interconnected everything is," Galbraith said in a news release

The study is published in the journal Nature Geoscience.