The Seaweed From Hell
The darker side of Mother Nature is making a comeback.

by Jeff Della Penna

There has been a whole set of frightening stories coming out of Australia about a freakish sea-grass, so toxic, fishermen say, that the touch of it is like getting splashed with acid. The spread of this weed has brought one fishing community, Moreton Bay, Queensland, to its knees. What once was a healthy shrimp and crab fishery of 45 boats has been reduced to a few desperate guys willing to risk the burns, rashes and boils to pay the bills.

These are proud and tough fishermen, who routinely risk their necks in high winds and big seas, but they’ve met their match against this little weed and even their gloves and their waterproof gear won’t protect them. Once this plant, or even the water laced with the plant’s toxins, touches any exposed part of their body, the fishermen quickly break out in rashes and sores. One fisherman reported that his skin was literally peeling away.

This hell-weed that’s causing all the ruckus goes by the species name, Lyngbya majuscula, a benthic filamentous marine cyanobacterium. That’s a type of seaweed, a blue-green algae, that carries a cyanobacteria. Scientists say it produces more than 100 toxins, probably as a defense mechanism. But the plant isn’t on the defensive. It’s on the offense and gaining ground fast.

Officially, Lyngbya majuscula causes localized skin, eye and respiratory irritation. But unlucky fishermen paint a more graphic picture. It’s common to hear tales of searing welts and little boils that burn at night. Horror stories of inflammation spreading across legs and torsos—lips inflamed, blistering up and peeling, eyes burned so badly that they become swollen shut. And when the stuff does heal, it leaves pockmark scars all over its victim’s body.

Now, Lyngbya majuscula and cyanobacteria is nothing new. They’ve been growing in the ocean for as long as water has been wet. They’re an ancient and diverse group of photosynthetic microorganisms, which inhabit many different and extreme environments on our planet. In fact, back when the oceans where more of a primordial stew, cyanobacteria and Lyngbya majuscula, where all over the place.

So, why are they suddenly becoming such an issue now? According to the National Research Centre for Environmental Toxicology in Brisbane, Lyngbya majuscula is turning up, not just in Moreton Bay, but also in at least a dozen places around the globe. Biological oceanographer, Judith O’Neil, of the University of Queensland’s marine botany lab, says that this indicates a high degree of biological adaptation. In fact,she has traced the Moreton Bay strain back to a bacteria and algae that flourished 2.7 billion years ago.

The consensus is that the organism is on the increase due to the continually high flow of nutrients into our ocean currents. Things like nitrogen and human waste, which are present in much higher densities. For example, over the last fifteen years the Brisbane and Moreton Bay area has become the fastest growing region in Australia. And, where people gather, so does their waste. In this case, 30 regional wastewater treatment plants have been pumping millions of gallons of partially treated sewage into the bay and its tributary rivers.

These nutrients are pushed around and eventually come in contact with the algae. Under the right circumstances, in just the right mix of temperature and density, there’s an algae bloom or explosion of the population.

For the last few thousand years, the waters of the world have been cleaner and the supply of nutrients much more diluted, so Lyngbya majuscula had a much harder time getting a foot hold. Plus, there has always been an abundance of sea animals that have been only too happy to feast on the cyanobacteria that did grow.

But today, things are different. The nutrients dumped into the ocean exist in much higher levels—to the point of saturation in some places, like Moreton Bay. The mean temperature of the ocean is also rising. So now, if Lyngbya majuscula explodes fast enough, the sheer mass of algae and bacteria will suck most of the oxygen right out of the water. The drop of oxygen kills or drives away potential predators. And guess what? A cyanobacterium thrives in the low oxygen environments, which allows for continued algae growth.

Back in Moreton Bay, the chemicals in the cyanobacteria stain the fishing nets a dark purple. Which, when dry, turns to a powdery residue. When the fishermen there move their nets, they have to be extremely careful not to inhale the dust or let it get into their eyes. And, they’ve learned quickly that if they’ve been working with any of their gear, they always wash their hands thoroughly before taking a leak.

A fisherman is said to have given the loose edge of a net a tug with his teeth to pull a knot tight. The poor guy’s mouth and tongue swelled up so badly that he couldn’t talk or chew his food for a week.

Queensland authorities are still playing down the effects of the Lyngbya majuscula. Some scientists are even blaming the fishermen and over-fishing for the current situation. But, before anyone starts pointing fingers at the fishing industry, it’s important to consider that Moreton Bay isn’t the only place in the world having problems with toxic algae. Almost half of the Earth’s landscape has been altered by farming, development and deforestation. All of which has greatly increased the volume of nutrient-rich discharge and runoff.

A lot of the planet’s natural filtering systems, like salt marshes and mangroves have been replaced with coastal development. More than half of the world’s population now lives in coastal regions, and continues to grow at a staggering rate of 1,000 new homes per day.

On the Gulf Coast of Florida, where about a billion gallons of sewage is pumped daily into the ocean, record levels of red tides continue to kill sea mammals.

In the Baltic Sea, home of the world’s largest ”dead zone”, summer blooms of cyanobacteria turn the waters into what the locals call “rhubarb soup.” So toxic, it will burn your eyes and your lungs if you get too close or find yourself down-wind.

On the other side of the globe, on parts of the island of Maui, the high tide leaves the expensive beachfronts littered with a type of green-brown algae. It smells so bad that the local property owners pooled their cash to pay for a tractor driver to rake the beach in the early dawn, before the tourists arrive.

Nature usually has many natural checks and balances, like algae-eating sea urchins, slugs, and schools of tiny fish, living on the floating clouds of plankton, that once kept the world’s estuaries and coastal waters clean. The Chesapeake Bay, the nation’s largest estuary, was once filtered by millions of oysters, and now stands testament to the devastating power of population growth and pollution on a traditional fishery.

The number of so-called ”dead zones” on the planet continues to grow. But, the dead zones aren’t really dead at all. True, they are very low in oxygen, which chases all the fish out, but they’re packed with living bacteria and other wild creatures that originally evolved when the ocean was a toxic soup.

November is springtime down-under in Moreton Bay. For fishermen there, one of the rights of spring is watching for the Lyngbya majuscula bloom. One day soon, millions of spores will simultaneously open and the seafloor will quickly be covered in dark green-and-black. In one recorded seven-week period, the Lyngbya majuscula bloom measured almost 100 square meters a minute. That’s equal to about one football field per hour. At its peak in December and January, the weed will cover over 30 square miles of Moreton Bay. You can see why they call it, ”The seaweed from hell.”