Local Impacts of Harmful Algae Blooms Around the United States
As the months and years tick by, our oceans get hotter; ice sheets crack and melt, trash islands collect, and — under certain conditions — toxic algae propagates in biblical proportions. Rarely brought to the forefront of environmental discourse, algae blooms choke the environments they invade, with devastating ecological and economic repercussions. The effects of human activity and urbanization on algae blooms must be more widely researched and discussed in order to limit their destruction.
Healthy ecosystems rely on the presence of algae, of many types, to sustain ideal biodiversity. A lack of algae in some ocean habitats can be lethal, but an overpopulation can be precisely the same. A “bloom” simply refers to sudden increase in the population of algae in an ecosystem, but the effects are far from pretty.
The first to feel the effects of these deadly blooms, are coastal communities, reliant on healthy, and diverse, waterway and ocean ecosystems. In ‘The Worst I’ve Ever Seen It’, Miami-based Patricia Mazzei interviews fisherman and locals faced with the prospect of traveling two or three times as far out from the coast to find crab, after a yearlong bloom, called the Red Tide, has been killing sea life — including the iconic Florida Stone Crab — off of Florida’s southern coast for over a year. These are not rich people working glamorous jobs; they are rural people, most living at or below the poverty line, and, when they face hardships, it can be difficult for them to garner the support they need. The apocalyptic title is pulled from the remarks of one Rick Collins, a crabber for nearly all his life, out of Everglades City, Florida. Faced with such grim prospects, Collins is unsure about his family’s future in the industry.
Ninety miles to the north of Everglades City, Eddie Barnhill, resident of Pine Island, is the man locals point to as emblematic of their troubles. A third generation crabber, Barnhill now sells ice commercially, from what was once his prominent fish house. When Mazzei asks him about his departure from the industry, he is candid about the reasons, saying, “I can’t survive in the fishing business. … I used to run 50 miles one way to go crabbing, and there ain’t crabs there now. There’s crabs 150 miles out, but you can’t do that in one day.” (Mazzei).
He’s speaking, of course, of the waters off of northeastern Florida, beyond the scope of the deadly tide, and far enough away that local economies on the southern tip, western coast, and isolated keys can’t even hope to compete. As dead, and dying, crab litter the ocean floor, the human settlements above, who rely on them, cannot help but take on a sickly pallor, themselves.
I became personally interested in the effects of algae blooms when, in 2015, a Blue-Green Algae bloom shut down beaches along the Russian River near my childhood home, in Sonoma County, due to the presence of anatoxin-a — a variety of cyanotoxin — in the water. One of the deadliest toxins known, anatoxin-a carries the haunting moniker Very Fast Death Factor (VFDF). Symptoms can appear from hours to minutes after exposure, and range from:
- Irritation and blistering of the exposed area, such as skin, eyes, or the soft tissues of the mouth and digestive tract
- Intestinal distress, including abdominal pain, nausea, and vomiting
- Organ toxicity and damage, respiratory distress and pneumonia, neuropathy, and death
The blooms now recur every summer, year after year, shutting beaches, and threatening young children, domestic and wild animals, the elderly, and others most vulnerable to the effects of the toxin. In my childhood, I spent plenty of afternoons in many of the rivers which snake around the county, and plagues like this were never an issue.
Elsewhere in the country, a deadly toxin lurks in Lake Superior, in the form of cyanobacteria. In the rising temperatures of the now-warmer Great Lake, this deadly blue-green algae propagated in the summer of 2018, causing worries for the health of the lake, and for the tourism trade that relies on it. Christine Hauser investigates, in ‘Algae Bloom in Lake Superior Raises Worries on Climate Change and Tourism’, but her findings do little to instill hope.
Only six years prior, park visitors reported the first known case of an observable blue-green algae bloom; it was a scummy layer spanning some fifteen miles of shore. The blooms, linked to sudden rains flooding the lake with sediment and pollutants, as well as to the rising water temperatures and lengthening summer season, have rapidly become common, with at least one other bloom in the summer of 2018.
Director of the Large Lakes Observatory at the University of Minnesota Duluth, Dr. Robert Sterner, and his team, became interested when the August bloom in Lake Superior reportedly spanned fifty miles of lake shore, but progress on the exact cause of these blooms has been slow. Hauser writes, of this, chillingly, “Dr. Sterner said that while scientists did not completely understand the causes and frequency of blooms, they start with warmer water. And Lake Superior, he said, ‘is one of the fastest-warming lakes on earth.’ ” (Hauser).
Indeed, as water warms, its capacity, for both oxygen and nutrients, increases, creating a more and more fertile space for opportunistic algae. Dr. Sterner is to-the-point on this, saying, “Something out there has changed, and the one thing we know securely is that the lake is warming.” (Hauser). The process of determining precisely which factors contribute to such conditions as these is a slow one, and the blooms themselves can take weeks to disperse naturally. Testing has shown that the cyanobacteria within the lake is, so far, non-toxic, but Dr. Sterner makes no bones about the severity: “We believe it to be the largest, most intense bloom yet.” (Hauser)
Cyanobacteria produce the deadly neurotoxins known, collectively, as cyanotoxins. So named for their ‘cyanotic’ quality of inducing respiratory distress, depriving the brain of oxygen, these toxins can easily kill an exposed pet or wild animal. The effects can be horrific on any ecosystem suffering from a prolonged algae bloom, something with which scientists in the Great Lakes area have become all too familiar.
It’s well-known that human impact on the landscape has some effect on these algae. Freshwater ecosystems support more and more algae as they warm, especially shallow bodies of water — such as canals, lakes, and lagunas — where sunlight can permeate much of the water.
Toxic waste from mass agriculture, such as chemical fertilizer, or runoff water, can weaken an already delicate ecosystem, making it a prime target to be infiltrated by algae. Phosphates and nitrates, commonly used in industrial fertilizers, create waters that are especially habitable for blooming algae, and as global climate change causes storms to become both more common, and more destructive, rain runoff dumps gallons of these chemical salts, such as ammonia and urea, into our waterways.
Despite this, the connection between the presence of fertilizers in waterways, and the epidemic of toxic blooms in those same waterways, is shaky. Working in San Francisco State University’s Romberg Tiburon Research Center, Maureen Auro and William Cochlan studied the effects of increased nitrogen levels on the growth of two species of Pseudo-nitzschia, a type of microalgae known as a phytoplankton, which bloom commonly off the coast of the San Francisco bay in brownish-purple patches.
The effects of offshore blooms can vary, both in severity and lasting impact, but even a mild bloom can devastate a delicate ecosystem. In a thick patch, such as those formed by Pseudo-nitzschia, photosynthesizing layers can blot out the sunlight, starving the fauna and corals below of much-needed heat and sunlight. The thick mats these blooms form can also quickly deplete the oxygen levels of the surrounding water, literally choking other organisms out of its path. Through a process called bioaccumulation, these toxins build up in the bodies of sea-dwelling creatures that consume them, exponentially increasing their concentration and potency.
Certain species of Pseudo-nitzschia produce domoic acid, which is absorbed by shellfish as they feed on the microalgae, where it remains in their tissues, being passed up the food chain to larger organisms, and even humans. The symptoms can be mild enough to mimic simple gastroenteritis, at a low level, but, as concentrations increase, can include permanent memory loss, coma, and death.
SFSU researchers compared growth of two Pseudo-nitzschia species when provided with different levels of nitrates sourced artificially, from industrial fertilizers, and naturally, from cold, salty water brought from deep below the ocean’s surface, in a process called upwelling.
In their assessment of the published research, writers for ScienceDaily noted, “In laboratory studies, Cochlan and former graduate student Maureen Auro found that natural and pollution-caused nitrogen forms equally support the growth of the harmful Pseudo-nitzschia algae and cause the production of the domoic acid, but in all cases the natural form of nitrogen caused the most toxic cells.” (SFSU). In fact, the presence of ammonia and urea, both nitrates, was shown to do little for Pseudo-nitzschia, when compared to naturally-occurring nitrates, but researchers failed to test the effects of an influx of man-made nitrates during a period of upwelling.
Additionally, “Cochlan cautions that when the pattern of upwelling is weaker, nitrogen from pollution could play an important role in sustaining a ‘seed population’ of harmful algae — a remnant that keeps the bloom going until upwelling resumes and the bloom is able to grow again and perhaps increase their toxic effect on the marine ecosystem.” (SFSU)
Rather than neatly wrapping up the question of human-driven effects on the algae blooms, this study perhaps raises more concerns than it quells. The Floridian bloom has been sustained for over a year, and while the Red Tide-forming Karenia brevis blooms, found in and around the Gulf of Mexico, are far from similar to our Pseudo-nitzschia, the thought that a constant supply of industrial chemicals could be contributing to conditions, so ideal for algae propagation, is concerning.
In a 2013 article for Think Progress, Joanna Foster details the sordid past, and the scum-crusted present, of Lake Erie. Bequeathed the dismal title, “North America’s Dead Sea”, during the 1960’s, the lake’s tender health makes for a sobering subject, as Foster is deliberate and analytical in her history lesson. According to her,
“Nearly 64 million pounds of phosphorus flowed into the lake each year from factories, sewer systems, fertilized farms and lawns. The nutrient pollution caused massive algal blooms which were often not only toxic themselves, but caused enormous dead zones in the lake, killing off fish and other marine life. The U.S. and Canada spent over $8 million in the 70s and 80s to upgrade lakeside sewage plants and dramatically cut phosphates in household detergents. And gradually, the lake began to come back to life, fish populations recovered and the lake’s $10 billion tourism industry rebounded.” (Foster)
Succinct in it’s delivery, this is, unfortunately, only Foster’s opener. In 2011, a cyanobacteria, called microcystis, bloomed over a fifth of the lake’s surface. Microcystis produces neurotoxins, as well as hepatotoxins, which attack the liver and can cause organ failure, especially in animals. The event was reportedly linked to a sudden, heavy rainstorm washing fertilizers into the lake from nearby corn and soybean farms.
Since then, the bloom has lingered seasonally.
The 2013 bloom, which prompted Foster’s writing, was the second-worst on record for the lake, but the following year brought with it such a mighty, and toxic, bloom that then-governor of Ohio, John Kasich, declared a state of emergency. Some half a million residents of nearby Toledo, and the surrounding counties, were left without drinking water for weeks. Before long, the bloom had entered the Ohio River, and made its way past four states, spanning over five hundred miles of river. Generally, the river flows too quickly for this to be possible, but low water level and lack of rainfall can turn a rushing river into stagnant, sticky puddle.
This bloom continued for over two months.
Could runoff from large-scale agriculture throughout California have a similarly exacerbating effect on algae blooms?
During the summer of 2018, precisely that happened. In June, a cyanobacteria bloom in Diamond Valley Lake, in Riverside County, turned toxic, and closed the lake for recreational activities for several days.
Diamond Valley Lake is a reservoir, providing clean water to nearly 20 million people throughout southern California, and was, luckily, not performing in that capacity during the bloom. Posted signs around the lakefront warned locals to avoid contact with the water, and to promptly gut, and thoroughly wash, any fish caught there.
Later that same month, three separate lakes in the San Joaquin Valley tested positive for nontoxic cyanobacteria, including Pine Flat Lake, near Sacramento, which prompted local officials to post warnings along the shore. Once again, drought conditions were cited as a contributing factor. These blooms were not isolated cases, and were in fact part of a larger trend of blooms across the state, made possible by record drought conditions lowering standing water levels, increasing the likelihood of a bloom.
The San Joaquin Valley is one of the most agriculturally dense areas of California. The temperate weather and lush soil have made it the ideal locations for over 600 companies to operate.
While we continue to not make these destructive blooms a part of our narrative around human-driven climate change, we ignore the plight of those most affected by them, and we allow conditions to worsen for all.
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