Sea life `facing greater risk of large-scale extinctions`
A team of the world’s leading marine scientists has warned that life in the world’s oceans faces far greater change and risk of large-scale extinctions today than at any previous time in human history.
|Last Updated: Aug 22, 2012, 08:09 PM IST|Source: Bureau
Washington: A team of the world’s leading marine scientists has warned that life in the world’s oceans faces far greater change and risk of large-scale extinctions today than at any previous time in human history.
The researchers from Australia, the US, Canada, Germany, Panama, Norway and the UK have compared events which drove massive extinctions of sea life in the past with what is observed to be taking place in the seas and oceans globally today.
Three of the five largest extinctions of the past 500 million years were associated with global warming and acidification of the oceans – trends which also apply today, the scientists said.
Other extinctions were driven by loss of oxygen from seawaters, pollution, habitat loss and pressure from human hunting and fishing – or a combination of these factors.
“Currently, the Earth is again in a period of increased extinctions and extinction risks, this time mainly caused by human factors,” the scientists stated.
While the data is harder to collect at sea than on land, the evidence points strongly to similar pressures now being felt by sea life as for land animals and plants.
The researchers conducted an extensive search of the historical and fossil records to establish the main causes of previous marine extinctions – and the risk of their recurring today.
Marine extinction events vary greatly. In the ‘Great Death’ of the Permian 250 million years ago, for example, an estimated 95 per cent of marine species died out due to a combination of warming, acidification, loss of oxygen and habitat. Scientists have traced the tragedy in the chemistry of ocean sediments laid down at the time, and abrupt loss of many sea animals from the fossil record.
“We are seeing the signature of all those drivers today – plus the added drivers of human overexploitation and pollution from chemicals, plastics and nutrients,” said co-author Professor John Pandolfi, of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland, an authority on the fate of coral reefs in previous mass extinction events.
The researchers wrote the paper out of their concern that the oceans appear to be on the brink of another major extinction event.
“There may be still time to act. If we understand what drives ocean extinction, we can also understand what we need to do to prevent or minimise it,” Prof. Pandolfi added.
Their findings appeared in the online edition of Trends in Ecology and Evolution (TREE).
ANI
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.
Cookies Setting
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device and the processing of information obtained via those cookies (including about your preferences, device and online activity) by us and our commercial partners to enhance site navigation, personalise ads, analyze site usage, and assist in our marketing efforts. More information can be found in our Cookies and Privacy Policy. You can amend your cookie settings to reject non-essential cookies by clicking Cookie Settings below.
Manage Consent Preferences
Strictly Necessary Cookies
These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work or you may not be able to login.
Functional Cookies
These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.
Targeting Cookies
These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They are also used to limit the number of times you see an advert as well as help measure the effectiveness of an advertising campaign. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.
Performance Cookies
These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we may not know when you have visited our site, and may not be able to monitor its performance.