Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




WATER WORLD
Clues in coral bleaching mystery
by Staff Writers
Stanford CA (SPX) Sep 11, 2013


File image.

Coral reefs are tremendously important for ocean biodiversity, as well as for the economic and aesthetic value they provide to their surrounding communities. Unfortunately they have been in great decline in recent years, much of it due to the effects of global climate change.

One such effect, called bleaching, occurs when the symbiotic algae that are essential for providing nutrients to the coral either lose their identifying photosynthetic pigmentation and their ability to perform photosynthesis or disappear entirely from the coral's tissue. Without a healthy population of these algae, the coral cannot survive.

There has been much attention given to the environmental conditions that trigger a reef's demise due to bleaching, but little is certain about the precise cellular and molecular mechanisms of the bleaching process. New research from Carnegie's Arthur Grossman brings into question the prevailing theory for how bleaching occurs on a molecular level. It is published in Current Biology.

Photosynthesis, the process by which plants, algae, and select bacteria convert the sun's light energy into chemical energy, takes place in a cellular organelle called the chloroplast. It has been theorized that the major cause of bleaching is the result of chloroplast damage due to heat stress, which results in the production of toxic, highly reactive oxygen molecules during photosynthesis.

Grossman and his team-led by Carnegie's Dimitri Tolleter and in collaboration with John Pringle and Steve Palumbi of Stanford University-demonstrated that bleaching still occurs if the algae are heat stressed in the dark, when the photosynthetic machinery is shut off. This is surprising since it means that toxic oxygen molecules formed in heat-damaged chloroplasts during photosynthetic reactions during the light are likely not the major culprits that cause bleaching.

Therefore other, as yet unexplored, mechanisms for bleaching must exist. This work suggests the existence of potentially novel mechanisms associated with coral bleaching. A mechanistic understanding of bleaching is critical for developing strategies to mitigate or eliminate the problem of coral decline.

The process of coral bleaching in the dark at elevated temperatures-and perhaps also in response to other stress conditions-could be a potential advantage to corals.

Grossman explains: "One theory that we are exploring is that under heat-stress conditions the corals eject the algal symbionts at night in order to avoid the production and accumulation of photosynthetically-derived toxic oxygen molecules during the day. If such molecules were to accumulate, they would threaten the viability of both the alga and its host."

The team's study also suggest that certain strategies proposed to protect reefs, such as shading the corals from high light, may not prevent high temperature-triggered bleaching (because bleaching would still occur in the dark). Clearly there is a need for more thorough molecular analyses to establish the various molecular causes of the bleaching processes.

Additionally, Grossman and Tolleter's work revealed some key details, such as the breakdown of specific parts of the photosynthetic apparatus when the corals are stressed. This process can be monitored and may potentially serve to evaluate the health of the reef and the risk of bleaching and death.

.


Related Links
Carnegie Institution
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





WATER WORLD
Report reveals missed opportunities to save water and energy
Stanford CA (SPX) Sep 11, 2013
Water and wastewater managers are missing substantial opportunities to save energy and money, according to a report published Wednesday (Sept. 4) by Water in the West, a research center at Stanford University. The report, "Water and Energy Nexus: A Literature Review," also identifies the amount of water used to extract resources such as natural gas, oil and coal, and to generate electricity. ... read more


WATER WORLD
Scientists say water on moon may have originated on Earth

Moon landing mission to use "secret weapons"

NASA launches spacecraft to study Moon atmosphere

NASA-Funded Scientists Detect Water on Moon's Surface that Hints at Water Below

WATER WORLD
Terramechanics research aims to keep Mars rovers rolling

New technology could make for smarter planet rovers

India prepares to launch country's maiden mission to Mars

SwRI study suggests debris flows on frozen arctic sand dunes are similar to dark dune spot-seepage flows on Mars

WATER WORLD
SpaceShipTwo commercial space liner breaks sound barrier in test

Andreas Mogensen set for Soyuz mission to ISS in 2015

NASA awards nearly $1.5B in support contracts

NSBRI and NASA Reduce Space Radiation Risks by Soliciting for Center of Space Radiation Research

WATER WORLD
China civilian technology satellites put into use

China to launch lunar lander by end of year: media

China launches three experimental satellites

Medical quarantine over for Shenzhou-10 astronauts

WATER WORLD
Three astronauts back on Earth from ISS: mission control

ISS Crew Completes Spacewalk Preps

Russian cosmonaut set for space station mission resigns

Russian cosmonauts to start searching for bacterium corroding ISS body

WATER WORLD
Japan sets new date for satellite rocket launch

Arianespace delivers! EUTELSAT 25B/Es'hail 1 and GSAT-7 are orbited by Ariane 5

Arianespace to "reach for the stars" with its Soyuz launch of Europe's Gaia space surveyor spacecraft

Ariane 5 build-up is completed for Arianespace upcoming flight with EUTELSAT

WATER WORLD
Coldest Brown Dwarfs Blur Lines between Stars and Planets

NASA-funded Program Helps Amateur Astronomers Detect Alien Worlds

Observations strongly suggest distant super-Earth has water atmosphere

Waking up to a new year

WATER WORLD
Chinese-built Bolivian satellite tested in space simulator

Indiana Jones meets George Jetson

New computational approaches speed up the exploration of the universe

Advancing graphene for post-silicon computer logic




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement