The mysteries of the deep

I've heard it said that we know more about the surface of the Moon than we do about the deep oceans on the Earth.

I've never seriously attempted to find out how accurate this is (and honestly, don't know how you'd compare the two), but I suspect it's substantially correct.  About seventy percent of the Earth's surface is covered by water, and given the difficulty of seeing what's down there -- even by remote telemetry -- it's no wonder we're still finding things in the ocean we never knew existed.

Take, for example, the study that appeared in Current Biology last week about the Clarion-Clipperton Zone.  The CCZ is the region between the Clarion Fracture Zone and the Clipperton Fracture Zone in the central Pacific, with an area of about six million square kilometers.  It contains several (apparently dormant or extinct) volcanoes, a number of submarine troughs of uncertain seismic activity, and a rough, mountainous topography.

[Image is in the Public Domain courtesy of the United States Geological Survey and the Department of the Interior]

The prevailing wisdom has been that most of the open ocean has relatively low biodiversity.  To put it more simply, that there just ain't much out there.  If you're in the middle of the ocean, any given cubic meter of water is unlikely to have many living things in it beyond single-celled plankton.  And -- supposedly -- the floor of the deep ocean, with crushing pressures, no light, and constant temperatures just above the freezing point of water, is often pictured as being pretty much devoid of life except for the bizarre hydrothermal vent communities.

That concept of the deep oceans needs some serious re-evaluation.  Last week's paper featured a survey of the abyssal life in the Clarion-Clipperton Zone, and found nearly six thousand species of animals...

...of which 92% were unknown to science.

The coolness factor of this research is tempered a little by the reason it was conducted.  The CCZ is being studied because of its potential for deep-sea mining.  The seafloor there has a rich concentration of manganese nodules, concretions of metal oxides and hydroxides (predominantly manganese and iron, with lower concentrations of other heavy metals), which are of immense value to industry.  Add to that the fact that the CCZ is in international waters -- so, basically, there for whoever gets there first -- and you have a situation that is ripe for exploitation.

What makes this even more complex is that the metals in the nodules are used, amongst other things, for high-efficiency electronics, including renewable energy systems.  The cost, though, might be the destruction of an ecosystem that we've only begun to study.

"There are some just remarkable species down there," said Muriel Rabone, of the Natural History Museum of London, who co-authored the study.  "Some of the sponges look like classic bath sponges, and some look like vases.  They’re just beautiful.  One of my favorites is the glass sponges. They have these little spines, and under the microscope, they look like tiny chandeliers or little sculptures.  There are so many wonderful species in the CCZ, and with the possibility of mining looming, it’s doubly important that we know more about these really understudied habitats."

So much of what humans have done seems to be blundering around blindly and only afterward seeing what the consequences are.  Perhaps we should investigate the ocean's mysteries before we attempt to use it for profit.

It seems fitting to end with a quote from H. P. Lovecraft, whose fascination with the ocean returns time and time again in his fiction: "But more wonderful than the lore of old men and the lore of books is the secret lore of ocean.  Blue, green, grey, white, or black; smooth, ruffled, or mountainous; that ocean is not silent.  All my days have I watched it and listened to it, and I know it well.  At first it told to me only the plain little tales of calm beaches and near ports, but with the years it grew more friendly and spoke of other things; of things more strange and more distant in space and in time.  Sometimes at twilight the grey vapours of the horizon have parted to grant me glimpses of the ways beyond; and sometimes at night the deep waters of the sea have grown clear and phosphorescent, to grant me glimpses of the ways beneath.  And these glimpses have been as often of the ways that were and the ways that might be, as of the ways that are; for ocean is more ancient than the mountains, and freighted with the memories and the dreams of Time."

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