The Glowing Waters of the Arabian Sea are Killing off Ocean Life

“The fish are migrating. They can’t get enough air here.” — Saleh al-Mashari, captain of a researcher vessel in the Gulf of Oman

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They are an ancient, primordial race of tiny organisms called noctiluca scintillans. And for millenia they have lived undisturbed in the deep waters between Oman and India. But as human fossil fuel burning forced the world to warm, this 1.2 billion year old species was dredged up from the deep.

Growing atmospheric and ocean heat fed the great storms that make up India’s southern monsoon. And as these storms intensified, they churned the waters of the Gulf of Oman, drawing the ancient noctiluca scintillans up from below. As these dinoflaggelates reached the surface they encountered more food in the form of plankton even as they gained access to more sunlight. Meanwhile, the strengthening monsoons seeded surface waters with nutrients flushed down rivers and streams and into the ocean.

(Noctiluca blooms have become a common feature of the Gulf of Oman and the Arabian Sea. They have also recently appeared off New Zealand, Tasmania, and Hong Kong. Such blooms are a result of warmer waters, more intense storms, related increasing rates of soil nutrients flushing into the oceans due to more intense rainfall events, and other conditions consistent with human-caused climate change. Image source: FaHaD.)

In this newly favorable environment, noctiluca subsequently bloomed. Covering the ocean in a green mat by day and an oddly iridescent blue when disturbed by the waves at night.

Phytoplankton are the base of the marine food chain and noctiluca has been voraciously devouring this key nutrient source over a Mexico-sized stretch of ocean water during recent years. As the noctiluca blooms expanded, they emitted toxins and an ammonia smell that some in the region are calling sea stench. And as the great mats died and decayed, they have robbed the surrounding waters of oxygen.

As a result, mass fish kills have been reported and much of the local sea life has fled the region.

March 2, 2017, image from the NASA MODIS satellite,  shows a mass of noctiluca scintillans blooms in the Arabian Sea off the coast of Oman extending past Pakistan to India.  (Image source: NASA and USGS, via AP)

Earth’s environment usually changes slowly, over the course of thousands or tens of thousands of years. In the past, this has given life a chance to adjust. But the human-caused climate change that is spurring the massive noctiluca blooms in the Arabian Sea is bringing on these new conditions over the mere course of a few decades. Thirty years ago, there was no visible trace of noctiluca in the waters of the Gulf of Oman and Arabian Sea. Now, they have come to dominate.

The oceans beneath the noctiluca mats are now increasingly robbed of life. Oxygen levels are plummeting. The fish can’t breathe there. And one wonders if or when a dangerous and deadly follow-on of hydrogen sulfide producing microbes will begin to spread up from the bottom regions of these oxygen starved waters.

Links:

Growing Algae Bloom in the Arabian Sea Tied to Climate Change

FaHaD

Noctiluca Scintillans

NASA

Hydrogen Sulfide in the World’s Warming Waters

Hat tip to Andy in San Diego

Hat tip to Mulga

Freaky Algae Bloom in North Atlantic Looks Like Dead Zone Eddy

Back in March, we reported on a new study that found algae blooms concentrating in ocean eddies off Africa were generating mobile dead zones threatening sea life in the Tropical Atlantic. Based on recent satellite imagery analysis, such phenomena may not just be isolated to regions off the Ivory Coast and Gibraltar. It instead appears that mobile and potentially oxygen-depleting algae blooms may also be cropping up in the far North Atlantic.

Deadzone Eddie

(Is the North Atlantic starting to see eddies which host ocean dead zones? The image above appears to show just such a feature. Image source: LANCE MODIS.)

Ever since mid-June, a strange feature has been visible in the satellite shot of an ocean region bracketed by Iceland, Svalbard, and the center of the Scandinavian Coastline. The area appears to include a major algae bloom which has been swept up into an ocean eddy. Measuring about 30 miles in diameter, the bloom displays visible aspects similar to its more southerly cousins. As with the mobile Tropical Atlantic Dead Zones off Africa, this swirl appears to have concentrated surface water nutrients — generating a region of more intensified microbial growth. A growth that now shows the tell-tale neon blue contrast of an algae bloom capable of tanking surface ocean oxygen levels.

High Latitude algae blooms are a prevalent occurrence during Spring and Summer as Ocean surface waters warm. And during recent years, rapidly warming waters and retreating sea ice has enabled more prolific algae blooms in northern seas. Though these waters contain more oxygen due to overall cooler temperatures, both the increased warmth and the large algae blooms generate a mechanism for loss of oxygen content in the vital surface zone.

Eddie algae bloom

(Strange algae bloom with characteristics similar to mobile Tropical Atlantic Dead Zones is visible as the blue dot at center frame in this July 2 LANCE MODIS satellite image.)

In addition to human forced warming of the ocean system reducing overall ocean oxygen levels, human fossil fuel burning, fertilizer runoff and deluges increasing run-off volume (due to global warming’s impact on the hydrological cycle) adds nutrients to surface waters. The nutrients come primarily in the form of nitrogen which rains down as fossil fuel fallout or is flushed in ever greater volumes down river systems as frequency of extreme rainfall events increase. As a result, the oceans are being loaded up with food for algae blooms.

A similar mechanism (usually triggered through enhanced volcanism) is thought to have lead to mass ocean die-offs in at least four of the five major mass extinction events. A mechanism which was likely most lethal when it started to enable anoxic ocean environments hosting microbes capable of producing massive volumes of hydrogen sulfide gas — which in the worst cases filled the oceans and vented into the atmosphere.

Ocean eddies further concentrate the nutrient run-off and fall-out through their churning action. So algae blooms have tended to intensify in these swirls of ocean currents. In the Tropical Atlantic, algae production in the eddies has been enough to generate large microbial die-offs and related depletion of oxygen — generating moving dead zones. If the newly identified algae blooms in these satellite photos are prolific enough to consume all the available nutrients in surface waters, they will also die off and, decaying, rob these waters of vital oxygen. Such an action could promote dead zone environments in northern waters in addition to those already documented in the Tropical Atlantic.

Links:

Ocean Dead Zones Swirl Off Africa

LANCE MODIS

Awakening the Horrors of the Ancient Hothouse — Hydrogen Sulfide in the World’s Warming Oceans

Anoxic Event

Hat Tip to Griffin (Who was the first to spot this particular algae bloom eddy in the MODIS shot)

Large Algae Bloom Still Ongoing As Toledo Officials Declare Water Safe to Drink

 

Algae bloom Lake Eerie

(Large algae bloom still visible in Lake Erie satellite shot on August 4, 2014. Image source: LANCE-MODIS.)

Warming, more toxic waters. It’s a problem directly driven by human-caused climate change. And for Toledo, Ohio, this weekend, it’s a reality that was starkly driven home as water services to half a million residents were suddenly shut off. There, in the waters of Lake Erie, a massive bloom of freshwater cyanobacteria pumped out enough poison to put human health at risk and force Ohio officials to declare a state of emergency.

Emerging Threat to Public Health

In Northern Ohio, water safety officials have been nervously testing Lake Erie supplies for many years now. Microbial blooms in western Lake Eerie were on the rise and the worry was that the new blooms may pose a future health threat as both climate change and agricultural run-off intensified.

By 2011, the wettest summer on record and warm waters in Lake Erie helped trigger a major outbreak of cyanobacteria blooms which ultimately resulted in more than 10 billion dollars in damage due to fouled waters, toxic beaches, and losses to the fishing and tourism industries of Lake Erie’s bordering states. Last year, a massive bloom caused some small northern Ohio towns to temporarily cut off water supplies. By last weekend, the entire water supply of Toledo, Ohio was under threat from the microbe-produced toxin called microcystin.

Water Poisoning by Microbes

Microcystin is a potent toxin produced by the small-celled, fresh water cyanobacteria. The substance is unsafe at levels greater than 1 part per billion in drinking water (according to the World Health Organization). Consumption of the toxin results in headaches, nausea and vomiting. Microcystin is directly toxic to the liver with exposure resulting in severe damage. It also results in damage to the digestive system and low levels of exposure have been linked in studies to various forms of abdominal cancer.

Since the toxin is a chemical that has already been produced by bacteria, usual sanitation methods, such as boiling water, are ineffective and may even help to concentrate the poison, making it more potent. So the toxin must be prevented from entering the water supply at the source — which can be difficult if much of the water source is contaminated, as is the case with Lake Erie.

A Threat Driven By Climate Change and Human Activity

As waters warm, they host larger and larger blooms of cyanobacteria harmful to animal life, including humans. The microbes thrive in warm, nutrient-rich water. And under climate change waters both warm even as runoff in certain regions increases due to more frequent bursts of heavy rainfall. This has especially been the case for the central and north central sections of the US, this year, which have suffered extensive and frequent downpours together with record hourly and daily rainfall totals in many areas.

The deluges flush nutrients down streams and into major bodies of water. The water, warmed by human-caused climate change, are already a haven for the cyanobacteria. So the blooms come to dominate surface waters. In addition, the runoff contains added nutrients due to large amounts of phosphorus and other agriculture-based fertilizers. It’s a combination that really gives these dangerous microbes a boost. Under such conditions, the massive resulting blooms can turn the surface lake water into green sludge.

Dead Zones, Anoxic Waters

Lake Erie algal blooms, August 2011

(Green cyanobacteria in Lake Erie during the large algae bloom of 2013. Image source: University of Michigan.)

Eventually, the cyanobacteria leech the surface waters of nutrients and begin to die out. As they do, they undergo decay which strips oxygen from the waters. Through this process, dangerous, anoxic dead zones radiate from areas previously dominated by large cyanobacteria blooms. The dead zone and toxin producing bacteria often result in large-scale fish kills and the wide-scale fouling of waters that can be so damaging to various industries. However, the dead zones themselves are havens for other toxic microbes — the hydrogen sulfide producing kind.

Water is Declared Safe — Information Still Unavailable to the Public

Today, water safety officials lifted the ban on water use for Toledo, claiming that water was now safe to use and drink after the water system was properly flushed. Officials apparently conducted six tests to confirm water supply safety but have not yet made results public. Personnel with the EPA unofficially stated that microcystin levels were at 3 parts per billion on the day the water was declared unsafe but that water was now safe for residents.

The declaration was met with widespread criticism due to the fact that data on water testing was not made publicly available, reducing confidence in the safety officials’ assertions and causing many residents to question their veracity. State and city water officials say they plan to post the data on their website, but have yet to confirm a time.

Meanwhile, the large cyanobacteria bloom is still ongoing. Experts expect the bloom to peak sometime in mid September and then begin to recede with the advent of fall and cooler weather. With more than a month and a half still to go, Lake Erie water troubles may just be starting to ramp up.

Links:

Toledo Water Ban Lifted, Results Kept Secret

Don’t Drink the Water

LANCE-MODIS

University of Michigan

Spring Rain, Foul Algae in Ailing Lake Eerie

Toxins in Water Lead to State of Emergency

 

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