Washington: Warmer water temperature and decreased levels of oxygen in the ocean will act together to push marine animals away from the equator to places in the ocean where the oxygen supply can meet their future needs, says a study. It will speed up the animals' metabolic need for oxygen, as also happens during exercise, but will hold less of the oxygen needed to fuel their bodies, similar to what happens at high altitudes, the researchers said.
About two thirds of the respiratory stress due to climate change is caused by warmer temperatures, while the rest is because warmer water holds less dissolved gases.
The study centred on four Atlantic Ocean species: Atlantic cod that live in the open ocean, Atlantic rock crab that live in coastal waters, sharp snout seabream that live in the subtropical Atlantic and Mediterranean, and common eelpout, a bottom-dwelling fish that lives in shallow waters in high northern latitudes.
Atlantic rock crab
Curtis Deutsch, associate professor of oceanography at University of Washington used climate models to see how the projected temperature and oxygen levels by 2100 due to climate change would affect these four species' ability to meet their future energy needs.
For all four species, the equator-ward part of the range would become uninhabitable because peak oxygen demand would become greater than the supply.
If current emissions continue, the near-surface ocean is projected to become warm by several degrees Celsius by the end of this century.
Seawater at that temperature would hold 5-10 percent less oxygen than it does now.
Viable habitats would shift away from the equator, displacing from 14 percent to 26 percent of the current ranges.
The authors believe the results are relevant for all marine species that rely on aquatic oxygen for an energy source.
The study was published in the journal Science.
- With inputs from Agencies
Unofficially observed annually on 8th June since its proposal in 1992 by Canada at the Earth Summit in Rio de Janeiro, Brazil, World Oceans Day was officially recognised in late 2008. US-based non-profit organization The Ocean Project has been coordinating it since 2003.
The day is observed with an aim to honour the world's oceans, celebrate the products the ocean provides such as seafood as well as marine life itself for aquariums, pets, and a time to appreciate its own intrinsic value. It also provides a unique opportunity to take personal and community action to conserve the ocean and its resources. World Oceans Day events include a variety of activities and actions, such as special outdoor explorations, beach cleanups, educational and action programs, art contests, film festivals, and sustainable seafood events.
Last year, The world celebrated "Healthy oceans, healthy planet" in the first year of a two-year theme for World Oceans Day. Nearly 1,000 events were held at aquariums, zoos, museums, recreational centers, youth clubs, schools, businesses, and countless individuals marked the day by doing something to keep our ocean healthy.
This year, add a 'Twibbon' to your Twitter profile in support of the oceans. Read the tweet from the offical feed on World Oceans Day below...