On the surface of Lake Erie between Canada and the United States, something lethal is spreading at an alarming rate. But it’s not just here; across the world harmful algal blooms are transforming our waters into hotbeds of sickness and disease. And for the humans and animals that inhabit the Earth, it’s a disastrous turn of events.
Algae are believed to have been on our planet for more than two billion years, and, typically, their presence does not give us any reason for alarm. In fact, we have grown accustomed to seeing many species – such as kelp and seaweed – in the oceans and freshwater lakes of the world.
Generally speaking, the term algae is associated with water-based organisms that survive by converting light into chemical energy – a process known as photosynthesis. Found in both salt and freshwater, they vary wildly in size from tiny microorganisms to huge kelps that can reach up to 200 feet long. And most of the time, they live in perfect harmony with planet Earth.
In fact, algae are a vital part of the ecosystem that keeps our planet alive. According to experts, at least 50 percent of our oxygen is produced by these organisms as they photosynthesize. Moreover, they also occupy an important place in the food chain of nearly every marine lifeform on Earth.
In the modern world, algae are useful for far more than just generating oxygen and feeding fish. Present in a number of human products, these organisms have been used as fertilizer and a source of food over the years. Furthermore, scientists are experimenting with creating both biofuel and climate change solutions from the primitive lifeform.
However, in recent times scientists have observed these organisms behaving in a different and far more terrifying way. In some parts of the world including Florida, a phenomenon known as a red tide has been wreaking havoc across the oceans. But what exactly is causing the water to turn such an alarming hue?
According to experts, a red tide is the result of an algal bloom – a phenomenon in which these marine organisms multiply at an alarming rate. Their numbers may eventually lead to depleted oxygen levels and all manner of other problems for the local marine ecosystem. Consequently, this can spell big trouble for the humans and animals living in the vicinity.
But algal blooms are posing a problem in the world’s freshwater lakes, too. There, this phenomena is often referred to as blue-green algae, although the organisms behind it are actually nothing of the sort. Unlike the lifeforms responsible for the ocean’s red tides, it seems, the culprit here is something known as cyanobacteria.
Unlike algae, cyanobacteria are actually bacterial cells, but they get their energy from light in the same way. Varying between 0.5 and 60 micrometers in size, these organisms also do not grow as large as their salt water counterparts. However, they are even more widespread and have just as many uses to humankind.
In fact, cyanobacteria can be found in almost every recognized habitat on planet Earth. From freshwater lakes to ocean, soil, desert rock and even the wastes of Antarctica, these tiny organisms crop up everywhere. According to experts, they are also believed to play a role in protecting the environment by preventing the erosion of soil.
But it is in the freshwater lakes of the world that cyanobacteria are becoming something of a curse. When conditions are right, these organisms – much like the algae in the oceans – can multiply rapidly and cause an algal bloom. Furthermore, just like its saltwater counterpart, this phenomenon can devastate the local ecosystems.
According to experts, these algal blooms are far from a new phenomena. Take Lake Erie – the vast body of water that spans the states of Ohio, New York, Michigan, Pennsylvania and the Canadian province of Ontario. Here, the problem has been present since at least the 1950s. Poor environmental practices over decades have created the perfect environment for these organisms to multiply at a breakneck pace.
“At one point, Lake Erie was considered a dead lake,” plankton expert at Bowling Green University Dr. Timothy Davis told The Guardian in January 2020. However, the authorities stepped in and placed limits on the amount of phosphorus that could be disposed of in the water. And once this nutrient was removed, the algal blooms disappeared.
Sadly, the clean-up effort was not to last, and by the 1990s Lake Erie’s surface was once again covered with algal blooms. Since then, the problem has only worsened. And for the roughly 500,000 nearby residents who rely on the lake as a water source, this has caused a lot of problems over the years.
One of the worst incidents occurred in Toledo, OH, in 2014. The city sits on the eastern shore of Lake Erie, and residents received some startling news that August. Apparently, their water supply had become so contaminated by algal bloom that they were no longer able to drink or even wash their hands with it.
Although the problem of unusable water was eventually resolved, cyanobacteria continued to bloom across the vast body of water. In July 2019 NASA images showed one patch in the western section of Lake Erie which measured around 300 square miles. And within two weeks, it had more than doubled in size.
Experts opined that the phenomena was particularly strong that year due to the weather, which saw calm conditions combine with excess rain. According to NASA, the lack of wind in July had allowed the cyanobacteria to gather together on the surface of the lake instead of being scattered by the gusts. Then, the following month, a stronger breeze churned up the water and sent the organisms down into the depths.
Lake Erie is far from the only place affected by algal blooms, however. In 2017 a red tide formed off of Florida’s Gulf Coast – wreaking havoc on the local ecosystem. And by August 2018 it stretched for around 100 miles. Interestingly, the phenomenon has been observed in the region since the 1500s when it was noted by Spanish explorers. But its recent incarnation is particularly extreme.
By October 2018 the red tide had spread eastward to the Atlantic Coast of Florida – closing beaches across the state. And the algae was multiplying at an alarming rate. In a 2018 interview with CNN, marine biology and ecology professor at the University of Miami Larry Brand discussed the organism’s startling behavior.
“It’s 15 times more abundant today than 50 years ago,” Brand explained. “I can’t think of any natural sources that have increased 15-fold.” After some time, the red tide off the coast of Florida finally dispersed and in early 2020 researchers witnessed the end of an algal bloom that had plagued the region for 14 months. However, that was far from the end of the matter.
In 2015 another vast algal bloom had appeared on the western coast of the U.S. – stretching all the way from California to at least British Columbia and possibly beyond. According to experts, it occurred thanks to a spot of unusually warm water first detected in the Pacific Ocean in 2013. Within this blob, temperatures were around 37°F higher than average, and this created the perfect conditions for algae to multiply.
By May 2015 the algal bloom had become the biggest and most enduring on record in 15 years or more, the National Oceanic and Atmospheric Administration found. As in other locations, this red tide caused widespread devastation – forcing fisheries up and down the west coast to close their doors.
But why exactly does this strange phenomena bring the fishing industry grinding to a halt? And what explains the beach closures and health warnings whenever it appears? Well, it turns out that an algal bloom does more than just turn lakes and oceans an unattractive hue.
Unfortunately, algal blooms can also prove exceptionally toxic to living things. For example, in August 2019 a woman in Wilmington, North Carolina, took her three dogs to cool off in a local pond. But just 15 minutes later, one of the animals began experiencing seizures. And after rushing to the veterinary clinic, the two other pets also became ill.
Tragically, all three dogs eventually died due to poisoning caused by the cyanobacteria lurking in the water. It’s believed that this can happen when animals come into contact with algal blooms – either through drinking or licking contaminated fur. CNN reports that toxins prove to be fatal in almost every case and a dog can be killed within minutes.
In salt water, meanwhile, algal blooms are also responsible for deaths throughout the animal kingdom. For instance, in 2015 strong winds off the coast of western South Africa churned the waters of the Indian Ocean into a nutrient-rich soup. And in such favorable conditions, a population of algae began to thrive.
As the resultant algae bloom sapped the oxygen from the water, great numbers of lobsters headed towards the shore in order to escape the red tide. But when the ocean receded, they found themselves stranded on land – too weak to make their way back to the sea. Before long, the beaches of the region were soon littered with dead creatures.
In fact, some 200 tons worth of rock lobsters reportedly died on South Africa’s beaches as a direct result of 2015’s algal bloom. But they’re far from the only creatures affected by the deadly red tide. During the 14-month crisis that struck the Florida coast, for example, an estimated 127 dolphins were killed.
Some 100 manatees and almost 600 sea turtles also lost their lives thanks to the toxic conditions in Florida. And the shellfish of America’s eastern coast have suffered another side-effect that’s even more terrifying from a human perspective. Exposure to algal blooms can apparently cause these organisms to become poisonous – with lethal effects.
In many locations, it is the threat of netting potentially deadly catches that forces fisheries to close their doors. In places like New Zealand, the fear has previously extended to a ban on recreationally harvesting shellfish in red tide zones. But there is worrying evidence to suggest that humans don’t even need to consume contaminated animals in order to experience negative effects.
The World Health Organization claims that exposure to the cyanobacteria found in freshwater algal blooms can cause a number of alarming symptoms. As well as vomiting and stomach cramps, the organisms can also cause muscle pain and even liver damage. Moreover, it’s not just drinking contaminated water that can lead to problems.
Apparently, humans can also experience troubling symptoms after merely coming into contact with algal bloom. And that’s why, when cyanobacteria contaminated Lake Erie in 2014, the residents of Toledo were advised against having any contact with the water.
In Toledo, the water problems persisted for three days before the authorities could get them under control. Eventually, the city forked out over $130 million to upgrade its water treatment facilities to the point where the cyanobacteria could be filtered out. But even now – six years later at the time of writing – there are still residents who refuse to drink water from the tap.
Meanwhile, harmful algal blooms (HABs), continue to be reported around the world. The Guardian newspaper reported that as many as 300 were logged in 2018 alone, and this number looks set to increase. But if this phenomena is caused by natural factors such as the weather and breeding organisms, why is it becoming a bigger problem than it was before?
It is thought that a number of different factors affect the formation of algal blooms across the world. At inland bodies of water such as Lake Erie, for example, experts believe that changing farming methods might be at least partially responsible for the phenomenon. In fact, the reappearance of cyanobacteria in the 1990s coincided with a shift towards the use of synthetic fertilizer in the surrounding fields.
“We went from agriculture that was small farms [and a] variety of crops to larger commercial farms that were harvested for essentially two row crops: corn and soya beans,” Davis told The Guardian. But these new methods meant an increase in fertilizer use and more nutrient run-off into the waters of Lake Erie.
But it’s not just farming that has had an impact on algal blooms around the world. Elsewhere, climate change has been highlighted as another cause behind the growing phenomenon. In Lake Superior – some 500 miles southwest of Lake Erie – clumps of cyanobacteria have appeared for the first time since records began.
Lake Superior has historically been too cold for algal blooms to form, but now rising temperatures have changed all that. Meanwhile, in the world of saltwater algae, climate change also has a role to play. Apparently, the amount of carbon stored in the oceans has increased rapidly over the years – creating bigger and more toxic blooms.
The climate crisis has also exacerbated the situation in other ways through increased rainfall and higher surface temperatures, experts believe. But how can the world be expected to tackle such a complex problem? In the future, researchers have suggested, we need to change farming methods and get to grips with global warming in order to prevent further disaster.
Meanwhile, some experts have proposed more direct methods – such as improved wastewater treatment – as a more immediate way of tackling the issue of algal blooms. And in certain areas, aquaculture programs have been successfully used to combat excess nutrients in salt water. But will we be able to get this deadly phenomenon under control before it causes permanent damage to our ecosystem? The truth remains to be seen.