|Leatherback saviors, for a while
Anna, a rare leatherback sea turtle which beached off the north end of Anna Maria Island in March 1999, was treated and released back into the Gulf of Mexico twice, only to return to shore. She was infected by fishing line entangling a flipper, which eventually was amputated, and she later died. Islander Photo: Bonner Joy
The Gulf of Mexico is dead, dead, dead
Ah, the joys of summer!
Brilliant blue skies, towering thunderheads that bring afternoon rain, balmy sea breezes, a riot of flowers and shrubs.
And a zone of dead water in the northern Gulf of Mexico that, by summer's end, will encompass an area about the same size as New Jersey.
The dead zone is hypoxic, lacking enough oxygen to keep any marine life alive. Fish and other movable critters flee the area; shellfish and other bottom dwellers without the means of locomotion die. It's an annual thing, and scientists believe it is growing larger and lasting longer each year.
The hypoxic state has its roots in the U.S. Midwest. Fertilizer containing nitrogen flows into the Mississippi River and is carried downstream to eventually end up in the Gulf. The nitrate-rich water acts as fertilizer for algae, which gorge themselves on the food source. As the algae die, they drop to the bottom and become food for bacteria. As the bacteria gorge, they absorb the available oxygen from the water, and the water "dies."
Researchers explained in the June 5 issue of "Science News" that the northern Gulf is a relatively static body of water without much in the way of "flushing." With an estimated 4.5 million gallons of nitrate-rich river water entering the area every second - yes, that's 4.5 million per second - the dead zone grows and grows until it reaches epic proportions.
However, come fall, the nitrogen input drops and the zone shrinks. That's the good news.
The bad news is that in other water bodies around the world the zones don't go away. There is a permanent dead zone in the Baltic Sea that stretches to something like 100,000 square kilometers. There is also a seasonal hypoxic region in Chesapeake Bay.
And a Virginia Institute of Marine Sciences scientist, Robert J. Diaz, said that his research indicates that the number of dead zones are roughly doubling every 10 years. As he puts it, historically "overfishing was the leading environmental issue affecting our seas. In the new millennium, it's going to be oxygen."
Scientists identified 68 dead zones worldwide in the early 1990s. Today, it is estimated there are about 150.
Historically, the dead zone in the Gulf dates to at least 1884. More recent data indicate that the annual cycle started in the mid-1970s. That's not hard to grasp when you remember that the Mississippi watershed encompasses about 41 percent of the lower United States, and a huge amount of that area is the nation's breadbasket, filled to overflowing with farms producing our veggies.
Most scientists agree that there is a fix to the problem: Pull the plug on the fertilizer. The problem is that pulling the fertilizer plug will also flush the farming industry in the nation. No more veggies, no more food, global famine.
The federal government is looking at ways to deal with the nitrogen problem, but there are no real regulations to address the amount of fertilizer used on farms. Voluntary programs advocating that less is more is one approach. Establishing riverside wetlands, which act as filters to any runoff, is another.
Unfortunately the programs are spotty and not doing a whole lot of good. In the river off Clinton, Iowa, there is something like 82,000 tons of nitrate flowing downstream each year.
It is estimated that nitrates have to be cut in half to really deal with the dead zone issue in the Gulf. As a goal goes, that's a good one, but not really feasible any time soon since it takes about 150 pounds of fertilizer to feed an acre of corn per year.
The Mississippi River watershed encompasses about 1.2 million square acres.
There is a bright glow on the dead zone issue, but its light is shrouded in calamity. A dead zone in the Black Sea is starting to diminish in size and duration, and some mussel beds are being reintroduced to an otherwise barren region of water. The reason?
With the fall of the Soviet Union, government subsidies for fertilizer were curtailed in much of the region. Farmers couldn't get the supplements for the crops, and the crops weren't fertilized. Of course, the crop production plummeted, but so too did the fertilizer runoff.
It somehow seems like a bad solution to a bad problem.
Of course, we had our own dead zone in miniature earlier this year, when the treated sludge from the Piney Point phosphate plant was dumped in Bishop Harbor, causing an algae bloom that caused a real mess. Fortunately, the area was small enough that crews could come in an scoop out the green stuff and haul it away.
Leatherback turtle update
Leatherback sea turtles are the largest of the marine reptiles, growing to a length of 6 feet and weighing upwards of 1,000 pounds. They can live up to 100 years.
Unfortunately, not too many of them are living these days.
Researchers have explained in the journal "Nature" that there were an estimated 115,000 leatherback turtles worldwide in 1982. The census counted about 35,000 12 years later, a 70 percent drop.
Satellite images of the turtles in the Pacific Ocean indicate that leatherbacks used some pretty proscribed migration routes that don't change all that much. The "turtle freeways" was to be good news for conservation efforts, as ships and other problems could be shunted to one side to allow the turtles the right of way.
Unfortunately, Atlantic Ocean leatherbacks meander all over the place, like drunk drivers, in search of food and clearing a path for them isn't really feasible.
Leatherbacks also just happen to dive to the same depth as longline fishers, producing lots of turtle catches in lieu of swordfish or tuna, another bad thing.
In fact, longline fishing has come under attack by three Florida environmental groups, which filed suit in U.S. District Court in Tallahassee against the National Marine Fisheries Service last week. The groups claim that longline fishing caused "needless injury and deaths of hundreds of threatened and endangered leatherback and loggerhead sea turtles," according to a wire report.
Anna Maria Island became familiar with leatherback turtles five years ago when "Anna" the turtle beached herself off the north end of the Island.
In what may have been the first sighting of the species on the West Coast of Florida - they usually are East Coast beach-bound - Anna had become entangled in some fishing line that eventually cost her a left-front flipper. She was treated at the Clearwater Marine Aquarium for an infection, and eventually released. Twice. Both times she beached again, and eventually was euthanized at the aquarium due to her limited abilities.
As Greg Harmon of the aquarium put it, "It turned out that there never was a solution to her problems, once she got tangled in that fisherman's discarded line. It's unpardonable that this turtle suffered for months because of one of us."
Dead zones do have one short-term saving grace in that fishing in the area just outside of the zone is often great.
Like rats leaving a sinking ship, marine life that can flee the hypoxic water do so. If fishers or shrimpers can find the zone and lurk along the edges, the fishing is usually pretty good. An 1884 account of what was recorded as the first acknowledgment of a dead zone was described as a "jubilee" by a Mobile, Ala., newspaper due to a prolonged run of good crab and fish yield in the waters off Alabama.