28 May 2011

OCEAN Rx: CHILLIN' WITH THE JELLIES


Here's what you need to do to feel better. Swim with the stingless jellies of Palau's Jellyfish Lake.






































Via Wikimedia Commons: 12, 3, 4, 5, 6

27 May 2011

HAPPY BIRTHDAY, RACHEL CARSON


It's the 104th anniversary of Rachel Carson's birth. She was with us for only 56 years—not nearly long enough.

Last year I had the privilege of writing an afterword for a fine-press limited-edition book of Carson's first published work, a lyrical essay called Undersea. The publisher of this volume is Nawakum Press, the preface by environmental historian and biographer, Linda Lear, and the illustrations by author, designer, and illustrator, Dugald Stermer.
























I'm grateful to Nawakum Press, who have been kind enough to let me post the afterward to her beautiful Undersea here.

So, happy birthday, Rachel Carson! This is for you.

Afterward
It's impossible to read Rachel Carson's deeply insightful essay 75 years after its publication and not run afoul of a sad truth: that she is not here to enjoy the plethora of new revelations emerging from the undersea world. Since her death in 1964, scientific investigation has illuminated much of the "eternal night" of her abyss. Already, tens of thousands of species have been added to the 230,000 species of marine animals known by the close of the 20th century. Our discovery of these new "folks" is not the consequence of a handful of men leisurely sailing the blue, but of thousands of women and men exploring every corner of the World Ocean with deep-towed cameras, sonar, submarines, remotely operated underwater vehicles, free-swimming autonomous underwater vehicles—an ever-evolving host of technologies allowing us to know what no one in 1937 could have imagined...

(Cirrate, or dumbo, octopod. Credit: Michael Randall.)

This cooperative endeavor has swelled Carson's beloved catalogue of periwinkles, starfish, and crabs to include otherworldly marvels: Dumbo ocotopods who swim by flapping earlike fins; wildcat tubeworms who drill for and feed on chemicals in decomposing oil; southern elephant seals who dive a mile and a half deep in search of prey living below the cusp of perpetual darkness; shoals of fish 20 million strong, swimming in schools the size of Manhattan.


 
(Tubeworms, Lamellibrachia luymesi, from a cold seep 550 meters/1,800 feet deep in the Gulf of Mexico. Photo: Charles Fisher via Wikimedia Commons.)  

Many discoveries have emerged from abyssal ecosystems unknown to Rachel Carson. The first hydrothermal vent was discovered only in 1977. The first cold seep in 1984. Carson understood the deep was fertilized by outflows from rivers, volcanoes, meteorites, and the rain of detritus from the ocean's surface. She could not have envisioned how the gas-fueled communities of the coldest abyss could feed themselves… how extremophile lifeforms could adapt to intense pressures and a sunless world and thrive in "lifeless" conditions by harvesting chemosynthetic—not photosynthetic—energy from hydrogen sulfide and methane. 


(Whale fall. Credit: NOAA.)

In Undersea, Carson marvelled at the resilience of the ear bones of whales and the teeth of shark that endured all the way to the bottom of the ocean. Imagine how she would have thrilled at the 1987 discovery of whale falls—those oases created by the sunken bodies of dead whales, each home to its own extremophile metropolis gathered to feed on the fallen bonanza of skin, muscle, bone, and blubber. Whale falls today are estimated to number some 850,000 worldwide, with many millions more in the recent past, before the age of commercial whaling reduced global whale populations by 90 percent. Each fallen whale is an island of life-support with a hundred-year-plus lifespan. 

(Lobster egg. Credit: Tora Bardal, from Nikon Small World 2009.)

The underwater world we've discovered since Carson's day redefines the old superlatives. Today's finds are bigger, deeper, darker, colder, farther, older. Technology combined with a growing lineage of scientific knowledge allows us to explore the heretofore unknowable. We visit communities of life thriving in blackness 2,300 feet below Antarctic ice. We follow pairs of mated seabirds flying 44,000-mile figure-eight loops around the Pacific in the 200 days between their nesting seasons. We rediscover Jurassic shrimp "extinct" for 50 million years alive and well in the Coral Sea. We magnify ocean water and find bacterial species in excess of 10 million. 

(Photo ©Julia Whitty.) 

Our sorrow at the absence of Rachel Carson in this expansive world is mitigated by another sad truth. The same alarming developments that compelled her to sound the clarion call of Silent Spring only a quarter century after the lyrical Undersea are evolving dangerously today. Delving deeper, we find the depths suffering from overfishing, pollution, dead zones, acidification. Scrambling to uncover new species, we find them disappearing faster than we can reach them, with more than a third of scientifically assessed species now in danger of extinction. Since Carson's hand helped guide the helm, the ship of science has shifted course to sail head-on into a typhoon of human excesses: habitat destruction, biological invasions, global-warming, overpopulation. The world Rachel Carson loved and defended grows more silent spring, summer, autumn, and winter.


(Robert Hines and Rachel Carson. Credit: USFWS.)

In the course of her all too short life, Carson had opportunity for only one brief dive below the surface, donning an old-fashioned diving helmet to stand upright in a hard current in bad visibility. Perhaps we could indulge a small literary license and take her underwater with us now—with modern equipment in excellent conditions. If she is tentative, as many novice divers are, we can offer her our hand to hold and descend together, taking the time to clear our ears, adjust our buoyancy. Somewhere along the free fall to the bottom, perhaps as the sea fans and anemones and shoals of fish begin to come into focus, she will let go our hand. Imagine the moment: the slim figure gently kicking her fins to hover over a reef and inspect a familiar tube worm. Worries about scuba tanks and regulators now forgotten, she wafts weightless through shafts of sunlight, afloat in blue wonder, Rachel Carson home at last.






















(Credit: slattery.matt at Flickr.)

25 May 2011

BIRTH OF A MARINE BIOLOGIST



'Course the otter's got a decent field study underway too.

24 May 2011

TORNADOES FUELED BY WARMING OCEAN

(Tornado. Credit: NOAA via Wikimedia Commons.)

The stats on tornadoes so far this year are horrifying. A record-breaking 482 people—now ABC News reports that 1,500 are unaccounted for in Joplin, Missouri—have been confirmed killed as of 24 May.

We know that spring's a bad season for tornadoes. We know that La Niña years fuel stormy Aprils.

But 2011 is redefining even those parameters.


(Preliminary map of April 2011 tornado tracks. Credit: NWS, NOAA.)

Here's what NOAA has to say about April alone:

  • April 2011 set a new record with a total of 875 tornadoes.

    • The previous April record was set in  1974 with 267 tornadoes.
    • The average number of tornadoes for the month of April during the past decade was 161.
    • The previous record number of tornadoes during any month was 542 tornadoes set in May 2003.
    • NWS [National Weather Service] records indicate 321 people were killed during the April 25-28 tornado outbreak.
    • NWS records indicate 361 people were killed during the entire month of April 2011.
       

(April 14, 2011 tornado over Tushka, Oklahoma. Credit: Gabe Garfield and Marc Austin, NOAA, via Wikimedia Commons.)

Leading up to April's extreme tornadoes were some extreme temperatures, noted Stu Ostro, Senior Meteorologist at the Weather Channel:

The temperature in Laredo reached 111 degrees the day prior to the peak [April] outbreak, the hottest on record at that location for so early in the season. Precipitation extremes have been extreme even by extreme precipitation standards, with April rainfall upwards of 20" in Arkansas and record levels on some rivers in the central U.S., juxtaposed with an exceptionally large amount of Texas being classified in extreme or exceptional drought. 

(May 22 storm moments before the Joplin tornado formed. Credit: NOAA.)

Now May is racing to catch up to and maybe even pass April. Here's what NOAA finds so far:

  • The National Weather Service's preliminary estimate is more than 100 tornadoes have occurred during the month of May 2011. 

    • The record number of tornadoes during the month of May was 542 tornadoes set in May 2003.
    • The average number of tornadoes for the month of May during the past decade is 298.
    • May is historically the most active month for tornadoes.

As I write, reports are rolling in about a new round of tornadoes—and deaths—in Oklahoma.

(The 1965 Elkhart, Indiana, double tornado. Credit: NOAA via Wikimedia Commons.)

Sunday's horrific twister at Joplin, Missouri, was likely a multiple vortex tornado [like the one in the photo above], says Thomas Schwein, deputy director of the National Weather Service’s Central Region, reports the Kansas City Star.

Jeff Masters' WunderBlog describes the Joplin tornado's nine-minute path thus:

A violent high-end EF-4* [Enhanced Fujita Scale] tornado [initial assessment] with winds of 190-198 mph carved a 7-mile long, 3/4 to one mile-wide path of near-total destruction through Joplin beginning at 5:41pm CDT Sunday evening.

*UPDATE: After surveying the Joplin tornado track, the NWS announced that its winds exceeded 200 miles per hour. This makes it the fourth EF-5 tornado this year, according to WunderBlog—and the most costly ever. Initial estimates: $1-3 billion.


You can get a sense of what that monster was like from this video—which due to darkness is mostly only audio. It's honestly one of the scariest things I've ever listened to.

You can hear the tornado rolling in about 01:20 into the video (perhaps the first of the multiple vortices?), then really winding up at 01:59. But that's nothing. At 03:00 all hell breaks lose.

(An F5 tornado. Credit: Justin Hobson {Justin1569 at en.wikipedia}, via Wikimedia Commons.)

So what's fueling this year's record-breaking tornado season? There are the usual suspects, which the Cliff Mass Weather Blog lists as:

  • Strong Instability
  • Large Vertical Wind Shear
  • Low Level Moisture 
  • Lift

His blog does a great job of explaining those in detail.























(Sea surface temperature contours in the Gulf of Mexico between May 20 and May 22, 2011. Credit: NOAA.)

And then there are sea surface temperatures.

Unusually warm surface waters in the Gulf of Mexico—about 2 degrees Fahrenheit/3.6 degrees Celsius warmer than normal—may be a factor in this season's tornado frequency and strength, according to National Weather Service director Jack Hayes.

Add that to an uncommonly southward jet stream track, reports Scientific American, and you've got a recipe for the kinds of disasters we've been seeing so far this year. 

(Hurricane Isabel. Credit: NASA via Wikimedia Commons.)

Warmer sea surface temperatures are also one of three reasons NOAA is forecasting a 65 percent chance of an above normal seasoncharacterized as 13 or more named storms, 7 or more hurricanes, and 3 or more major hurricanes—in the Atlantic this year. 

THE PELAGIC ZONE


Here's some of the most beautiful footage of one of my favorite worlds—the bottomless blue waters far offshore known as the pelagic zone. Life here shines.

Whether you've had the good fortune to visit this realm or not, you're in for a treat with this short film by Rafa Herrero Massieu, shot in the waters around the Canary Islands. 

A few highlights to look out for, with timecodes:

  • Rare underwater footage of a beaked whale (not sure which species): 01:10
  • Common dolphins showing their gorgeous colors: 01:16
  • An Atlantic spotted dolphin emitting signature whistles: 01:26
  • Bryde's whale (I think, or else a Sei whale): 03:23

(Loggerhead turtle. Credit: ukanda via Wikimedia Commons.)

Because big life is relatively sparse in the pelagic zone, encounters between individuals tend to generate a lot of curiosity. 

You can see how all these species investigate the novelty of a person in their world—particularly the pilot whales at 03:00 and the triggerfish at 03:21.

For more of Rafa Herrero Massieu's films, visit his blog: NacidasDelMar (Born of the Sea), or his Vimeo page.

























(Strata of the pelagic zone. Measurements in meters. From here.)

20 May 2011

CELESTIAL SEAS


Views of our beautiful Milky Way.

All images below cover the complete 360-degree celestial sphere, via a series of stitched frames forming a panoramic, with the Milky Way as the central line or arc. Except the last image, which is a close-up, relatively speaking.















Courtesy of Wikimedia Commons, from top to bottom: 1, 2, 3, 4.

It's well worth clicking on the images to see the larger sizes. If you have the bandwidth, clicking on the number 2 link (above) to see that image in its original too-big-for-blogspot size.

19 May 2011

VOICE OF THE DOLPHINS
























In his newly released book, The Voice of the Dolphins, filmmaker Hardy Jones reports his story of a life spent working with dolphins—working to understand them and working to save them. 

Ultimately, and with a sad irony, this dolphin work proves important to Hardy's own survival. He writes:

This memoir covers three phases of my more than thirty years spent among dolphins and other sea creatures: my initial, exhilarating encounter with friendly dolphins; my subsequent discovery that these creatures are mortally threatened by both slaughter and the chemical contamination of our oceans; and, finally, my diagnosis with a form of blood cancer that has clear links to the same chemical toxins that are causing disastrous consequences among dolphins.
























(Atlantic spotted dolphins. Credit: Bmatulis via Wikimedia Commons.)

Like all love stories, Hardy's story with the dolphins—Atlantic spotted dolphins in the Bahamas, spinner dolphins in Hawaii and Tahiti, orca in the Pacific Northwest and Norway, to name a few—is full of beauty, discovery, and wonder. 

The book resonates with these passages. Here Hardy describes swimming for the first time in the wild with dolphins who did not flee him... a feat even Jacques Cousteau considered impossible in 1978 when Hardy pulled it off.

Dolphins raced at me from all directions, their eyes wide and bloodshot with excitement. The sea was a cacophony of breaking waves, my own gasping, yells, outboard motors, and the creaky-door buzzing of dolphin sonar. Whenever I surfaced, I tried to get some idea of how the filming was going, but no one was even remotely coherent. Words tumbled out of ecstatic faces...
I made a surface dive and swam down among a mixed group of juvenile and adult dolphins, blending into their formations, banking and turning in mid-water. It seemed I had no need to breathe, that I’d assumed properties of a dolphin just by being among them. When my air did run out, I clawed my way back to the surface and gasped for breath, often to find a trio of dolphins accompanying me.



(Photo from here.)

But like many love stories, Hardy's with the dolphins is also full of pain and sickness. In 1979 he went to Japan to film the slaughter of dolphins. This was the first of many trips to talk, listen, and argue with the fishermen in defense of the dolphins—all done decades before The Cove filmmakers got there. 

Hardy writes of being haunted by the two irreconcilable dolphin worlds he'd come to know:

Again and again, especially in early morning hours when I couldn’t sleep, my thoughts returned to the brutal images of dolphins piled on the beaches of Iki... I placed an aerial photograph of the dead dolphins littering the beach at Iki on my desk. Next to that photograph, stood a framed print of two dolphins, looking at me as we swam side by side in the turquoise waters of the little Bahama Bank.  


(Shamu Stadium, SeaWorld. Credit: David Bjorgen via Wikipedia.) 

Hardy's first film on the dolphin slaughter in Japan was called Island at the Edge—a masterpiece of restrained, elegant reporting. But that was only the beginning.

In the course of my travels to Japan, I’d come to realize that... a major part of the incentive to local fishermen to pursue and kill dolphins is cash put on the table by international dolphin traffickers who come to Taiji to pick out "show-quality" dolphins. They pay enormous amounts, as much as $150,000 for a dolphin trained in Taiji. The service includes trainers who will accompany the locally trained dolphin to its final destination in one of the many dolphinaria in Japan, as well as to China, Korea, French Polynesia, Turkey and Egypt. For dolphins, this must be the equivalent of an alien abduction. The captive dolphins eventually end up in a cement tank performing for fish in aquarium shows and "swim-with-dolphins" programs around the world.

(Dolphins in tuna nets. Photo from here.)

From stories of the brutal dolphin entertainment industry, Hardy was eventually drawn into other problems, including the monumental tragedy of six million dolphins drowned in tuna nets.

His film If Dolphins Could Talk helped tip that story in a new direction.

When the show hit the air, the results were explosive. The emotional impact of the footage was amplified by a short PSA hosted by George C. Scott that included a 900 number, produced for the show by Stan Minasian of the Marine Mammal Fund. The result was a pile of six thousand telegrams hitting the desk of the chairman of Starkist tuna demanding an end to catching tuna by setting nets on dolphins. Within weeks, Starkist announced that it would no longer accept tuna caught on dolphin. The dolphin-safe label was born and is today overseen by Earth Island Institute and the Marine Mammal Fund. My film synergized with years of hard work by several organizations and was a major conservation victory.


In 2003, Hardy was diagnosed with multiple myeloma, a rare blood cancer. A few weeks later, he was offered an exciting film project with the PBS series Nature. The film that would eventually come to define him was called The Dolphin Defender.

In follow-up conversations with [PBS], we mapped out the general shape of the film that would be an episodic journey through my career of making films about dolphins. It would combine archival footage shot over a period of several decades with newly shot footage that would fill in gaps in the story and bring it up to date... I hadn’t looked at a lot of that old film for years, and as I started to screen bits and pieces, memories flooded back with a combination of exhilaration, nostalgia, and not a few thoughts of how young I looked. The reaction was, no doubt, intensified by my new-found sense of mortality. 

Amazingly, Hardy eventually discovered that his rare disease was not rare in dolphins. Investigating further, he found that places where dolphins were suffering were also myeloma hot-spots for people.

But I'll leave the rest of that amazing chapter of Hardy's story for you to read.

(Hardy Jones.)

There are a lot of old friends in Hardy's book, and many facile sketches of others in that strange realm where dolphins, diving, and filmmaking intersect. I'm there too, because Hardy and I worked together for 20 years making nature documentaries. I shared many of the adventures and some of the horrors he describes in The Voice of the Dolphins.

After more than three decades, Hardy's relationship with the dolphins he loves and admires has mellowed. You can get a sense of that in this clip (below) from BlueVoice.org—Hardy's nonprofit dedicated to fighting to end the slaughter of dolphins and to exposing levels of toxins in the marine environment harmful to marine mammals and humans. Hardy included.



Among Dolphins from BlueVoice.org on Vimeo.

So buy the book. It's vivid, vibrant, impassioned, generous, inspirational, and packed with one good sea yarn after another.

Best of all The Voice of the Dolphins is loaded with dolphins—old friends with names and personalities and great stories that only Hardy can tell on their behalf.

16 May 2011

SEA WOMEN
























In southern Japan women freedivers have been collecting the flora and fauna of the sea for 2,000 years. Traditionally they wore only loincloths in far-from-warm waters.

I'm not sure when or by whom these photographs were taken, but they may be the work of Fosco Maraini in his 1962 book, Hekura: The Diving Girls' Island.































(All images above from SkindivingHistory.com.)

 'Course traditions don't get much more exciting than mostly-nude women in the water with pearls and sharks and whatnot. These divers are known as ama, or sea women, and they form a cultural bridge connecting the fantasies of all of humankind.
























(The first Ama. Via Japonisme.)

A Japanese myth about the first ama tells of a perfect pearl stolen by a dragon king. Here's the rest of the tale, from Japonisme:

Fujiwara no Fuhito (659-720) went in search of the pearl to the isolated area where he met and married a beautiful pearl diver named Ama, who bore him a son. Ama, full of love for their son, vowed to help recover the stolen pearl. After many failed attempts, Ama was finally successful when the dragon and grotesque creatures guarding it were lulled to sleep by music. Upon reclaiming the treasure, she came under pursuit by the awakened sea creatures. She cut open her breast to place the pearl inside for safekeeping; the resulting flow of blood clouded the water and aided her escape. She died from the resulting wound but is revered for her selfless act of sacrifice for her husband Fuhito and their son.




Interestingly, ama improve their endurance underwater over time, peaking in their middle years, with some managing incredible longevity. According to this documentary, the oldest working diver on Hegura Island is 92 years old.


(Haenyo, or sea women, statue in Jeju, Korea. Credit: Chosun Bimbo 2 via Wikimedia Commons.)

Korea has women divers too—called haenyo, or sea women. Here are a few excerpts from a 1996 article in Diver magazine describing their way of life:

At the top of a rocky cliff on the South Korean island of Jeju, several people sit motionless in the lotus position, meditating. They are dressed in shimmering black neoprene, white cotton head covers and old-fashioned, oval masks. These are the Hae Nyeo female divers, who practise a tough, dangerous profession that has continued for centuries. After meditating they will enter the sea to dive, breath-holding, for shells, tunicates, octopus, crabs, seaweeds—anything on the seabed that is edible. They hardly ever use boats, simply jumping in from the rocky coastline and swimming sometimes long distances to get to the reefs they wish to hunt...

I enter the water with my camera. A Hae Nyeo diver hovers at the surface 15m above me, and raises her head to take her last deep breath before shooting down head first. Quick and nimble, fishlike, she glides over rocks, under overhangs and squeezes into narrow openings. Her well trained eyes quickly pick out wanted prey—shells and starfish—and she uses her piece of metal rapidly to detach them. It is amazing how long this woman can hold her breath and work hard under water. Back at the surface she puts the prey in the circle net before heading straight back down for another attempt. For an hour I observe the Hae Nyeo. Their physical performance is absolutely astonishing, each female diver heading down to depths of up to 20m about 30 times over...

Nowadays, the Hae Nyeo divers are well respected and honoured, but this was not always so. The women were not accepted by high society. They were thought to be uneducated, wild, stubborn, much too independent, and the vocabulary they used was considered outlandish. As if this was not enough, they dared to dive into the sea half naked! The Hae Nyeo have, though, maintained a special community of their own. Their appearance and vocabulary still reflect the fact that they are tough and self-confident women.
Despite their abilities, the female divers do get into trouble. High waves and currents can lead them to complete exhaustion, and through an interpreter I learn that one still-active 70-year-old diver has lost "many" of her female companions to the sea. Some, she says, had become stuck while trying to get a shell of extraordinary size out of an opening; and others had been taken away by strong currents. The worst accident the old female diver remembers is a shark attack, in which a female diver who must have hurt herself badly and lost a lot of blood was tracked down by a big shark and killed.

Soon, says the elderly diver, the female divers will have disappeared for good. Despite the good money to be earned from selling seafood, young girls nowadays don't want to continue the breath-hold hunting traditions of the Hae Nyeo. A way of life that has existed for centuries could soon be gone.


Sadly, it seems the younger women have been tamed.

15 May 2011

"THE LONELY PIPEFISH"



Up, up, slender   
         As an eel’s
         Child, weaving   
Through water, our lonely   
Pipefish seeks out his dinner,

         Scanty at best; he blinks
         Cut-diamond eyes—snap—he   
         Grabs morsels so small
Only a lens pinpoints them,
But he ranges all over

         That plastic preserve—dorsal   
         Fin tremulous—snap—and   
         Another çedilla
Of brine shrimp’s gone ...
We talk on of poetry, of love,

         Of grammar; he looks   
         At a living comma—   
         Snap—sizzling about
In his two-gallon Caribbean
And grazes on umlauts for breakfast.

         His pug nosed, yellow
         Mate, aproned in gloom,   
         Fed rarely, slumped,
Went deadwhite, as we argued on;   
That rudder fin, round as a

         Pizza cutter, at the
         End of his two inch
         Fluent stick self, lets his eyes
Pilot his mouth—snap ...
Does his kind remember? Can our kind forget?

(Photo from here.)

14 May 2011

DIVING THE MID-ATLANTIC RIDGE

(Photograph: Alexander Mustard/Solent.)

From The Guardian:

A diver swims between the Eurasian and North American tectonic plates in Silfra Canyon, Thingvellir National Park, Iceland. In this photograph the American plate is on the left, and the Eurasian on the right.

























(From here.)

13 May 2011

TUBES


Tales from the Tube from Jarred Hancox on Vimeo.

DOES A MONSTER FLOOD HAVE TO FUEL A MONSTER DEAD ZONE TOO?

(Sediment-laden water pours into the Gulf of Mexico from the Mississippi and Atchafalaya Rivers. Credit: Norman Kuring, Ocean Color Team.)

As you can see from the image above, a lot more than water comes down a river.

The Mississippi and its distributary, the Atchafalaya River, carry an average of 230 million tons of soil into the Gulf of Mexico every year. On flood years, the total runs a lot higher.

That's going to cause downstream problems this year... all the way downstream to the ocean. But before we go there, let's take a quick look at how the system works.

(Credit: USGS.)

The graphic above shows sediment concentration and sediment discharge for major US rivers. The giant half-circle in the Gulf represents the Mississippi/Atchafalaya discharge.

Why are the two bundled together? Because they're really the same river: the parentheses bracketing a 100-mile-wide delta.


(I'm still searching for the credit for this map... My apologies, I'll update when I locate it.)

Before 1927's epic flood, the Mississippi was free to wander the delta, whiplashing between courses whenever a huge flood year like this one pushed it over its banks—a process known as delta switching.

In the above image you can see some of its historical courses and when it ran them.
















(Credit: USGS via Wikimedia Commons.)

For much of the 20th century the Mississippi has been trying to leave its current course and flow back through its old Atchafalaya course. In his always-excellent WunderBlog, Jeff Masters explains:

There is a better way to the Gulf—150 miles shorter, and more than twice as steep. This path lies down the Atchafalaya River... Each year, the path down the Atchafalaya grows more inviting. As the massive amounts of sediments the Mississippi carries—scoured from fully 41% of the U.S. land area—reach the Gulf of Mexico, the river's path grows longer. This forces it to dump large amounts of sediment hundreds of miles upstream, in order to build its bed higher and maintain the flow rates needed to flush such huge amounts of sediment to the sea. Thus the difference in elevation between the bed of the Mississippi and the Atchafalaya—currently 17-19 feet at typical flow rates of the rivers—grows ever steeper, and the path to the Gulf down the Atchafalaya more inviting. Floods like this year's great flood further increase the slope, as flood waters scour out the bed of the Atchafalaya.

(Mississippi River watershed. Credit: Shannon via Wikimedia Commons.)

Of course it makes no difference to the Gulf of Mexico whether the floodwaters come down the Mississippi or the Atchafalaya. What matters to the ocean is what's in the river water.

The Mississippi drains the entirety of America's breadbasket... therefore its fertilizerbasket, pesticidebasket, fungicidebasket, and manurebasket.

River water, with its organic nutrient loads, naturally acts as a fertilizer on ocean chemistry. Add in the runoff from farms and feedlots—with nitrogen and phosphorous loads from chemical fertilizers and manure—and you get a Miracle-Gro on steroids.

Which, paradoxically, fuels an oceanic dead zone.

(Phytoplankton. Credit: NOAA MESA Project.)

I wrote extensively about this problem in my Mother Jones cover, The Fate of the Ocean, a few years back.

The Gulf of Mexico dead zone forms every summer when spring floods wash the nutrients downriver into the Gulf to fertilize massive oceanic plant blooms. The marine plants are mostly single-celled phytoplankton.

The problem is the phytoplankton bloom so fast and furiously that their primary consumers, the zooplankton, can't bloom fast enough to keep up and eat them all. Many phytoplankton die uneaten.

They're then consumed by detritivores, the microorganisms like bacteria that feed on (that is, decompose) dead things. Thus the Gulf's spring and summer phytoplankton blooms also fuel detritivore blooms.
















(Video frame of dead zone of the Baltic Sea, showing the seafloor covered with dead or dying crabs, fish, and clams killed by low oxygen levels. Courtesy Wikimedia Commons.)

Unfortunately, growing populations of detritivores use up much of the dissolved oxygen in the water. Marine life that can't swim away or otherwise flee these increasingly hypoxic zones, suffocate and die. You can see the results in the image above.


(Black skimmers on the nest, Mississippi. Photo © Julia Whitty.)

Researchers are expecting a mighty dead zone will form from this year's mighty floods. The Gulf, staggering back from last year's oily assaults on its ecosystems, will likely pay a heavy price... again, smack in the middle of the breeding season for everything from seabirds to tuna... and smack in the middle of important seasons for commercial fisheries, sports fisheries, and tourism.

So is there anything we can do about the problem? The Microbial Life Education Center at Minnesota's Carleton College—in the heart of Mississippi farmland—suggests these fixes:

  • Using fewer fertilizers and adjusting the timing of fertilizer applications to limit runoff of excess nutrients from farmland
  • Control of animal wastes so that they are not allowed to enter into waterways
  • Monitoring of septic systems and sewage treatment facilities to reduce discharge of nutrients to surface water and groundwater
  • Careful industrial practices such as limiting the discharge of nutrients, organic matter, and chemicals from manufacturing facilities

The solutions are relatively simple and highly effective. A similar course change has already been used to remediate the effects of overly nutrient-rich waters flowing into the Great Lakes.

(The Atchafalaya River enters the Gulf of Mexico. Photo © Julia Whitty.)