Enormous blooms of algae painting the waters green, sickly blue, or blood-red. Algae producing toxins making water unsafe to drink or swim in. Making fish, shellfish and crabs unsafe to eat. Generating life-snuffing dead zones of low oxygen and, potentially, producing deadly hydrogen sulfide gas ranging our lakes, seas, and oceans.
This is what happens when the world is forced to warm, when run-off due to climate change induced extreme rainfall events increases, when the land that run-off comes from is loaded with fossil fuel based fertilizers, and when fossil fuel burning itself generates a constant fall-out of nitrogen from the skies. In ancient hothouse events, similar forces generated mass extinctions in the world’s waters. And through fossil fuel burning we’re setting off a related hothouse type stress to the life-giving liquid we all rely upon. A stress that is yet worsened due to the efficiency with which we are able to load the air, land, and seas with environmental toxins that aid in the generation of algae blooms of an intensity nature alone would have never kicked off.
(In a human-warmed world, toxic algae blooms that threaten Toledo, Cleveland and Akron water supplies are becoming all too common. Algae biomass graphic for the 2013 and 2014 Lake Erie algae blooms provided by NOAA.)
Lake Erie in the Firing Line
In the US, one of the most vulnerable bodies of fresh water to this kind of toxic algae growth is Lake Erie. Over recent decades as the local climate changed, the water warmed. Weather patterns resulted in increased heavy rainfall events. Increased farm industry and fertilizer use meant that much of the run-off was heavily laden with algae food. And the atmosphere itself became loaded up with nitrogen. In addition, the lake is more vulnerable to a life-snuffing stratified state in which the top and bottom layers fail to mix. A final blow came from an invasive species of mollusk — the zebra mussel — which changed the food web in such a way that it favored the growth of the toxic algae we see today. All these factors combined to make the surface waters more and more vulnerable to large, toxic algae blooms and the follow-on formation of dead zones.
Since the mid 1960s, late summer algae blooms have been a regular occurrence on the lake. But more and more now, the blooms are prolific enough to threaten city water draws.
In 2011, Lake Eerie suffered its worst algae bloom on record. At that time, fully 20 percent of the lake was covered in the toxic stuff. Then, both Ohio and Canadian cities along the lake had to shut off water intakes to prevent toxins entering the water system. During 2014 the blooms had again threatened water supplies forcing Toledo to shut its valves. Now, a new algae bloom is threatening Cleveland, Toledo and Canadian water supplies. And, according to NOAA officials, the current bloom may be nearly as intense and widespread as the 2011 event. NOAA notes:
The bloom will be expected to measure 8.7 on the severity index with a range from 8.1 to potentially as high as 9.5. This is more severe than the last year’s 6.5, and may equal or exceed 2013, which had the second worse bloom in this century. The severity index runs from a high of 10, which corresponds to the 2011 bloom, the worst ever observed, to zero.
Toxic Algae Visible From Satellite
As of yesterday, the widespread bloom of toxic algae was plainly visible in the LANCE MODIS satellite shot:
(A large and growing toxic algae bloom in Lake Erie visible from satellite on August 5. It’s a bloom that may eventually prove to be the largest such event on record for the Lake. Image source: LANCE MODIS.)
A huge swath of the western end of the lake was covered with the stuff as of August 5, 2015. A clearly visible green blob blanketing much of Erie’s western surface. Researchers out on boats monitoring this year’s outbreak described the lake as being painted in a thick sheen of goop.
According to NASA, the particular kind of algae that now appears annually in Lake Eerie is called Microcystis. It produces a toxin that is highly dangerous to humans. If consumed, Microcystis may cause numbness, nausea, dizziness, vomiting, lead to liver damage and even result in death. One part per billion in water is all it takes to hit unsafe levels. And boiling toxin-laced water is no remedy — resulting in further concentration of the dangerous stuff.
During August of 2014, unsafe levels were reached at Toledo intakes causing water officials to shut down the lake water supply there. This year, officials are closely monitoring the water supply ready to hit the off switch if the water again hits a dangerous threshold.
Sadly, Lake Erie isn’t the only place on Earth suffering the impacts of hothouse-spurred toxic algae blooms. In the Pacific Ocean, a massive blob of hot water is hosting a red tide of record depth and extent. That particular bloom risks the expansion of an already large dead zone, the proliferation of anoxic and hypoxic waters, and the potential for bottom water production of toxic hydrogen sulfide producing bacteria. In the North Atlantic, swirls of algae blooms are generating mobile dead zones even as the far North Atlantic is witnessing a massive blue-green algae bloom (more on these dangerous human warming related events in upcoming posts).
Hat Tip to Andy in San Diego
Hat Tip to Colorado Bob