Pollution of oceans triggers `rise of slime'

Scientists describe reverse evolution as primeval species overtake advanced organisms

July 30, 2006|By KENNETH R. WEISS | KENNETH R. WEISS,LOS ANGELES TIMES

MORETON BAY, Australia --The fireweed began each spring as tufts of hairy growth and spread across the seafloor fast enough to cover a football field in an hour.

When fishermen touched it, their skin broke out in searing welts. Their lips blistered and peeled. Their eyes burned and swelled shut. Water that splashed from their nets spread the inflammation to their legs and torsos.

"It comes up like little boils," said Randolph Van Dyk, a fisherman whose powerful legs are pocked with scars. "At nighttime, you can feel them burning. I tried everything to get rid of them. Nothing worked."

As the weed blanketed the bay over the past decade, it left fishing nets coated with a powdery residue. When fishermen tried to shake it off the webbing, their throats constricted, leaving them gasping for air.

After one man bit a fishing line in two, his mouth and tongue swelled so badly that he couldn't eat solid food for a week. Others made an even more painful mistake, neglecting to wash the residue from their hands before relieving themselves over the side of their boats.

For a time, embarrassment kept them from talking publicly about their condition. When they finally did speak up, authorities dismissed their complaints - until a bucket of the hairy weed made it to the University of Queensland's marine botany lab.

Samples placed in a drying oven gave off fumes so strong that professors and students ran out of the building, choking and coughing.

Scientist Judith O'Neil put a tiny sample under a microscope and peered at the long, black filaments. Consulting a botanical reference, she identified the weed as a strain of cyanobacteria, an ancestor of modern-day bacteria and algae that flourished 2.7 billion years ago.

O'Neil, a biological oceanographer, was familiar with these ancient life forms but had never seen this kind before. What was it doing in Moreton Bay? Why was it so toxic? Why was it growing so fast?

The venomous weed, known to scientists as Lyngbya majuscula, has appeared in at least a dozen other places around the globe. It is one of many symptoms of a virulent pox on the world's oceans.

In many places - the atolls of the Pacific, the shrimp beds of the Eastern Seaboard, the fjords of Norway - some of the most advanced forms of ocean life are struggling to survive while the most primitive are thriving and spreading. Fish, corals and marine mammals are dying while algae, bacteria and jellyfish are growing unchecked.

Where this pattern is most pronounced, scientists evoke a pattern of evolution running in reverse, returning to the primeval seas of hundreds of millions of years ago.

Jeremy B.C. Jackson, a marine ecologist and paleontologist at the Scripps Institution of Oceanography in La Jolla, says we are witnessing "the rise of slime."

For many years, it was assumed that the oceans were too vast for humanity to damage in any lasting way. Even in modern times, when oil spills, chemical discharges and other industrial accidents heightened awareness of man's capacity to injure sea life, the damage was often regarded as temporary.

But over time, the accumulation of environmental pressures has altered the basic chemistry of the seas.

Industrial society is overdosing the oceans with basic nutrients - the nitrogen, carbon, iron and phosphorus compounds that curl out of smokestacks and tailpipes, wash into the sea from fertilized lawns and cropland, seep out of septic tanks and gush from sewer pipes. These pollutants feed excessive growth of harmful algae and bacteria.

At the same time, overfishing and destruction of wetlands have diminished the competing sea life and natural buffers that once held the microbes and weeds in check.

Evidence is surfacing around the globe.

Off the coast of Sweden each summer, blooms of cyanobacteria turn the Baltic Sea into a stinking, yellow-brown slush that residents call "rhubarb soup."

On the southern coast of Maui, high tide leaves piles of green-brown algae that smell so foul that condominium owners have hired a tractor driver to scrape them off the beach every morning.

On Florida's Gulf Coast, residents complain that harmful algae blooms have become bigger, more frequent and longer-lasting. Toxins from red tides have killed hundreds of sea mammals and caused emergency rooms to fill up with coastal residents suffering respiratory distress.

North of Venice, Italy, a sticky mixture of algae and bacteria collects on the Adriatic Sea in spring and summer. It washes ashore, fouling beaches, or congeals into submerged blobs, some bigger than a person.

Organisms such as the fireweed have been around for eons. They emerged from the primordial ooze and came to dominate ancient oceans that were mostly lifeless. Over time, higher forms of life gained supremacy.

Jackson uses a homespun analogy to illustrate what is happening. The world's 6 billion inhabitants, he says, have failed to follow a homeowner's rule of thumb: Be careful what you dump in the swimming pool, and make sure the filter is working.

Baltimore Sun Articles
|
|
|
Please note the green-lined linked article text has been applied commercially without any involvement from our newsroom editors, reporters or any other editorial staff.