Carbon-eaters on the Black sea

Aug 03, 2012
acquired July 15, 2012

(Phys.org) -- This brilliant cyan pattern scattered across the surface of the Black Sea is a bloom of microscopic phytoplankton. The multitude of single-celled algae in this image are most likely coccolithophores, one of Earth’s champions of carbon pumping. Coccolithophores constantly remove carbon dioxide from the atmosphere and slowly send it down to the seafloor, an action that helps to stabilize the Earth's climate.

This image of this swirling blue bloom was captured on July 15, 2012, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. Note that the image is rotated so that north is to the right. scientist Norman Kuring of NASA’s Goddard Space Flight Center suggested the bloom was likely Emiliania huxleyi, though it is impossible to know the species for sure without direct sampling of the water.

Coccolithophores use carbon, calcium, and oxygen to produce tiny plates of calcium carbonate (coccoliths). Often called “stones” by researchers, coccoliths resemble hubcaps. During their lifespan, coccolithophores remove carbon from the air, “fix” or integrate it into what is effectively limestone, and take it with them to the seafloor when they die and sink or when they are consumed (and eventually excreted) by zooplankton and fish.

These micro-stones are thought to speed up the ocean’s biological pump, according to William Balch, a senior research scientist at the Bigelow Laboratory for Ocean Sciences and a member of the Suomi NPP science team. Without this dense calcium carbonate ballast for sinking particles to the depths, less would be drawn down into the ocean. The net result would be higher atmospheric concentrations of carbon dioxide.

But as Balch points out, the ever-increasing amount of carbon dioxide in our air could upset this biological pump. Excess carbon dioxide is making the ocean more acidic, which may change the conditions that promote coccolithophore growth. “Ocean acidification is highly relevant to coccolithophores,” said Balch. “We are trying to understand if it would slow the ocean’s biological pump by inhibiting coccolithophore calcification. If they can’t calcify, they can’t make their limestone plates that pull all the sinking particulate carbon to the seafloor.”

Explore further: Investigators research the Laguna del Maule Volcanic Field, Chile

add to favorites email to friend print save as pdf

Related Stories

Surprises from the ocean: Marine plankton and ocean pH

Jun 21, 2011

The world's oceans support vast populations of single-celled organisms (phytoplankton) that are responsible, through photosynthesis, for removing about half of the carbon dioxide that is produced by burning fossil fuels – ...

Recommended for you

Better forecasts for sea ice under climate change

Nov 25, 2014

University of Adelaide-led research will help pinpoint the impact of waves on sea ice, which is vulnerable to climate change, particularly in the Arctic where it is rapidly retreating.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.