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Did The Human-Warmed Ocean Just Kill 8,000 Murres?

Around the world, mass sea creature die-offs have been occurring at an alarming rate. Off the US West Coast alone, the past three years have seen severe losses along almost ever link of the marine food chain from sea stars, to salps, to crabs, to sea lions. Many of these deaths have been linked directly or indirectly to impacts caused by a chronic warming of the region’s ocean surface dubbed ‘the hot blob.’

Now, a tragic and heart-wrenching new die-off has been recorded in the region of Prince William Sound. There, according to recent reports in the Washington Post, more than 8,000 murres — a kind of deep-swimming sea bird — were found dead. Washed up on shore, the mures bodies were shrunken and emaciated. Their stomachs completely empty of food.

Researchers noted that the mass death was likely due to starvation. But the potential cause given for the starvation was rather more ominous.

The Link to Human Warming of the World Ocean

Mures feed on small fish that swim within the top 300 feet of the ocean surface. The graceful murres ride the airs above the water until they catch sight of a school of these fish. Swooping in from above, the mures plunge toward their prey, snaring them with rapier-quick thrusts of their beaks.

Such fish usually swim close to the coast — thriving in the cold, nutrient-rich waters off Prince William Sound. But warm the waters up by just a little and the fish may leave — following their own food supply into colder regions.

sea surface temperature anomaly map

(The hot blob still holds sway over the Northeastern Pacific. This despite a series of strong El Nino storms and a somewhat flattening of the Jet Stream. It’s an extreme ocean warming that has been ongoing for more than two years. One that’s been linked to the mass deaths of numerous marine creatures. Image source: The National Weather Service.)

And the waters near and around Prince William Sound have been much warmer than normal during recent years. As of January 14th, 2016, sea surface temperatures in the region have ranged from 1 to 4 degrees Celsius above average. Extremely high differentials for an ocean surface that, during the Holocene, rarely varied by more than 1 or 2 degrees from typical ranges.

This extreme Northeastern Pacific warming is but an aspect of a larger heating trend ongoing in the global ocean system due to a rampant human emission of greenhouse gasses. This massive burning of fossil fuel has dumped hundreds of billions of tons of carbon into the world’s atmospheres and oceans — setting off a raging greenhouse effect and causing the Earth surface to warm by more than 1 degree Celsius above 1880s levels. It may not sound like much, but 1 C is just 1/4 the difference between now and the last ice age — but on the side of hot. And this 1 C warming happened in just 130 years where at the end of the last ice age the same amount of warming would have taken 25 centuries.

A Hothouse Dead Zone For Prince William Sound?

To the oceans and to the innocent creatures that live within, upon and above it, such a rapid accumulation of heat is a brutal insult. It removes whole habitats. It forces sea creatures to change their patterns of migration. It makes the surface waters more suitable for the kinds of dangerous algae blooms that produce ocean dead zones. Zones of low or zero oxygen in which very few forms of life can survive.

Prince William Sound Dead Zone

(Prince William Sound dead zone visible in this December 6, 2015 satellite shot? Tell-tale greens and blues hint that a large algae bloom may be robbing the waters around the sound of much needed nutrients and oxygen. A kind of new deadly ocean environment that is proliferating as sea surface temperatures warm into ranges in which dead zone producing microbes can thrive. Image source: LANCE MODIS.)

And it’s this kind of generation of an ocean killing field that is perhaps the most brutal and terrifying aspect of what we’ve already done to our planet. What the legacy of our fossil fuel carbon emissions will continue to do for decades to centuries to, perhaps, millennia.

And sadly, looking at the NASA MODIS satellite data, we do see an indication of the kind of algae bloom that may be depleting the waters near Prince William Sound of that life-giving oxygen. We see the tell-tale greens and blues of a large bloom of the kind that can rob waters both of nutrients to support fish life and of oxygen itself. Visual analysis alone cannot positively identify this kind of bloom with 100 percent certainty. Water samples must be taken in the area and analyzed. But scientists asking the very pertinent question — did global warming cause this? — may only need to take a look at the composition of this bloom to get their answer.

An answer that won’t save the thousands of already dead murres, but that might help us build the resolve to prevent more catastrophes like this one. To stop burning fossil fuels and halt the accumulation of a terrible build-up of heat forcing that is ripping the very underpinnings of life in the oceans asunder.

UPDATE — MODIS Chlorophyll Sensor Yet Another Indicator of Dangerous Algae Bloom in the Region of Prince William Sound

Further analysis of NASA satellite data provides yet more evidence that a dangerous algae bloom began showing up in the waters near Prince William Sound at the start of December.

December 6 MODIS Shot of Prince William Sound With Chlorophyll Layer

(December 6, 2015 NASA MODIS satellite shot of Prince William Sound with chlorophyll production overlay. Chlorophyll production in all ocean regions near the sound show up as elevated with some areas hitting the top of the graph at 20 mg per cubic meter [indicated in red]. Link: LANCE MODIS.)

High levels of chlorophyll in the waters near Prince William Sound provide yet one more instrumental indication of a large algae bloom in the region. As noted above, major algae blooms can rapidly remove nutrients from the water, creating a population crash as the algae starve themselves off. In the mass die-off of algae that follows, microbial decomposition can rob large areas of surface waters of oxygen — killing fish and other sea life or driving it away.

Warm waters provide an environment that tends to support these kinds of large algae blooms and is a primary reason why human heating of the world ocean is dangerous to ocean health. In addition, warmer waters hold less oxygen in suspension even as changes to ocean currents tend to generate more stratified oceans — preventing the kind of mixing that keeps oceans both oxygen and life-rich.

In any case, the added chlorophyll signal coming from Prince William Sound and the nearby ocean region are yet one more indicator that initial suspicions among ocean researchers may well be correct — abnormally warm waters related to human-forced climate change was probably a key trigger involved in the mass death of sea birds there.

Links:

LANCE MODIS

The National Weather Service

Mysterious Mass Death of Seabirds Baffles Scientists

Hat Tip to Colorado Bob

Hat Tip to Leland Palmer

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