Featured Research

from universities, journals, and other organizations

Toxic oceans may have delayed spread of complex life

Date:
February 28, 2013
Source:
University of Exeter
Summary:
A new model suggests that inhospitable hydrodgen-sulfide rich waters could have delayed the spread of complex life forms in ancient oceans. The research considers the composition of the oceans 550-700 million years ago and shows that oxygen-poor toxic conditions, which may have delayed the establishment of complex life, were controlled by the biological availability of nitrogen.

Inhospitable hydrodgen-sulfide rich waters could have delayed the spread of complex life forms in ancient oceans, a new model suggests.
Credit: roza / Fotolia

A new model suggests that inhospitable hydrodgen-sulphide rich waters could have delayed the spread of complex life forms in ancient oceans. The research, published online this week in the journal Nature Communications, considers the composition of the oceans 550-700 million years ago and shows that oxygen-poor toxic conditions, which may have delayed the establishment of complex life, were controlled by the biological availability of nitrogen.

In contrast to modern oceans, data from ancient rocks indicates that the deep oceans of the early Earth contained little oxygen, and flipped between an iron-rich state and a toxic hydrogen-sulphide-rich state. The latter toxic sulphidic state is caused by bacteria that survive in low oxygen and low nitrate conditions. The study shows how bacteria using nitrate in their metabolism would have displaced the less energetically efficient bacteria that produce sulphide -- meaning that the presence of nitrate in the oceans prevented build-up of the toxic sulphidic state.

The model, developed by researchers at the University of Exeter in collaboration with Plymouth Marine Laboratory, University of Leeds, UCL (University College London) and the University of Southern Denmark, reveals the sensitivity of the early oceans to the global nitrogen cycle. It shows how the availability of nitrate, and feedbacks within the global nitrogen cycle, would have controlled the shifting of the oceans between the two oxygen-free states -- potentially restricting the spread of early complex life.

Dr Richard Boyle from the University of Exeter said: "Data from the modern ocean suggests that even in an oxygen-poor ocean, this apparent global-scale interchange between sulphidic and non-sulphidic conditions is difficult to achieve. We've shown here how feedbacks arising from the fact that life uses nitrate as both a nutrient, and in respiration, controlled the interchange between two ocean states. For as long as sulphidic conditions remained frequent, Earth's oceans were inhospitable towards complex life."

Today, an abundance of nitrate, in the context of an oxygenated ocean, prevents a reversion to the inhospitable environment that inhibited early life. Determining how Earth's oceans have established long-term stability helps us to understand how modern oceans interact with life and also sheds light on the sensitivity of oceans to changes in composition.


Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.


Journal Reference:

  1. R.A. Boyle, J.R. Clark, S.W. Poulton, G. Shields-Zhou, D.E. Canfield, T.M. Lenton. Nitrogen cycle feedbacks as a control on euxinia in the mid-Proterozoic ocean. Nature Communications, 2013; 4: 1533 DOI: 10.1038/ncomms2511

Cite This Page:

University of Exeter. "Toxic oceans may have delayed spread of complex life." ScienceDaily. ScienceDaily, 28 February 2013. <www.sciencedaily.com/releases/2013/02/130228113447.htm>.
University of Exeter. (2013, February 28). Toxic oceans may have delayed spread of complex life. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/02/130228113447.htm
University of Exeter. "Toxic oceans may have delayed spread of complex life." ScienceDaily. www.sciencedaily.com/releases/2013/02/130228113447.htm (accessed October 1, 2014).

Share This



More Plants & Animals News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
Powered by NewsLook.com
California University Designs Sustainable Winery

California University Designs Sustainable Winery

Reuters - US Online Video (Sep. 27, 2014) Amid California's worst drought in decades, scientists at UC Davis design a sustainable winery that includes a water recycling system. Vanessa Johnston reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins