Bathymetric map, click for GEBCO high resolution image
The deep benthos is simultaneously the largest and least explored ecosystem on the planet. Covering nearly 60% of the Earth’s surface, it supports an almost unimaginable reservoir of biodiversity, rivaling all terrestrial habitats combined. Its microbial and metabolic diversity have revolutionized our view of how life is sustained, not once, but twice (first with the discovery of chemoautotrophic organisms at hydrothermal vents, and again with the discovery of cognate communities at methane cold-seeps). In spite of these major discoveries, the deep benthos is essentially invisible. Only a select few will ever witness it first hand, while for the rest, it will remain a dark and unfathomable abyss.
This places the deep benthos in a precarious position. Human activities that influence the deep sea go unnoticed. Without a thorough understanding of its ecology, it is impossible to assess the damage caused by anthropogenic impacts. Although recent and ongoing studies have shed light on many species and communities, the deep benthos remains largely unexplored. Two studies, both released this week, reveal simultaneously how little we know about the deep benthos and how human impacts, even unintentional ones, could shape this ecosystem.
Continue reading Rumors from the Abyss: visions of a future without deep sea conservation
If the marine productivity is iron limited, then adding iron should increase phytoplankton growth. This growth will absorb carbon dioxide from the atmosphere in order to fuel photosynthesis and on a global scale, has the potential to mitigate global warming by absorbing the extra carbon dioxide emitted by human activities. But is it really that simple?
Purple indicates areas of low productivity where fertiilization could take place. From http://www.palomar.edu/oceanography/iron.htm
After the first description of this hypothesis by John Martin, eight mesoscale experiments were conducted by scientists through the Woods Hole Oceanographic Institution, described in great detail on their project website. Basically, they concluded that although iron fertilization does encourage plankton growth, the carbon that is sequestered during that growth does not permanently stay sequestered in the ocean, but is released back into the atmosphere through decomposition. Therefore, even if the whole earth were fertilized, the sequestration would not be effective enough to make up for the use of coal-fired power plants.
~Bluegrass Blue Crab