Kill Krill: A Base of the Food Chain May Be at Risk

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An Antarctic krill, the startimage of the virtual microscope of krill where you can click into details of the animal to get higher magnifications
An Antarctic krillCredit: Uwe Kils / Dr. Habil
Ruth Schuster
Ruth Schuster

Eons after the whale and the snail, humans have noticed the charms of krill. The spiking commercial popularity of the tiny shrimp-like crustaceans is not a good thing. Krill aren’t rock-bottom on the global food chain but they’re pretty close. Themselves dining on phytoplankton, which are microscopic water plants, krill in turn are consumed by a vast array of animalia from bigger shrimp to birds to, famously, baleen whales – and now us.

This augurs ill for the krill, which is increasingly included not only in fish food (think: farmed salmon) but in products for humans, say Prof. Dr. Bettina Meyer from the Helmholtz Centre for Polar and Marine Research, in the journal Nature Communications Earth & Environment

The problem is that krill abundance fluctuates greatly in various places and – here’s the snag – we don’t know why, the research team explains. We know little about krill procreation habits and have difficulty preventing overfishing if we don’t know what krill do. Solutions for the nonce: study the ways of the krill, instate international fishing regulations and do it globally. Also it would be good to do this fast because the oceans are warming.

Ocean mixing is diminishing

Evidently ignoring the growling of their respective great leaders, a collaboration of scientists from the United States and China report in Nature Climate Change that the oceans are becoming stably stratified because of global warming. Sound like a good thing? It is not. Why? Because the more stable the layering (cold dense salty water at bottom, warmer lighter fresher water on top), the less the layers mix, and the less oxygen and carbon mixes into the water column from the surface, among other things. How bad is the situation? The team calculates that the top 2,000 meters of ocean has become more stratified by 5.3 percent since 1960. If the estimate is confined to the top 150 meters, the increase in stratification is estimated to be as much as 18 percent.

Ocean color difference when two water masses meetCredit: Jiang Zhu

Deep sea warming faster than thought

Although the oceans’ stabilizing stratification is slowing the dissipation of surface heat, the ocean deep is heating faster than had been anticipated. New data shows sea bottom temperatures fluctuate more than had been thought (in fact, they hadn’t been thought to fluctuate at all) – and a warming trend is now detectable in the deep, says the American Geophysical Union in Geophysical Research Letters. No, a megalodon isn’t going to spring out of a thawing sea floor, more’s the shame. But after a decade of measuring seafloor temperatures hourly at four depths in the Argentine Basin of the Atlantic off Uruguay, scientists seem almost as shocked to observe a warming trend of 0.02 to 0.04 degrees Celsius. Shrug not. Normally deep-sea fluctuations are thousandths of a degree, the AGU says. What will this mean for our endeavors to survive the ravaging of our planet? Stay tuned.

Thawing permafrost connected to tsunami risk, of all things

Among the risks involved in thawing permafrost – explosive methane emissions, sinkhole formations, collapsing land and infrastructure – we forgot tsunamis. How could we? But permafrost isn’t just a tundra thing. High mountains also have permafrost, which simply means “permanently frozen ground.” Except that in our age of global heating, the permafrost has been losing both the perma and the frost elements. It’s been melting, including on mountain slopes overlooking bodies of water – such as, the Guardian reports, the Barry Arm in Alaska. Landslides into water are notorious causes of tsunamis.

Permafrost: The Tipping Time BombCredit: Yale ClimateConnections/Youtube

NASA shows Bolivian fires from outer space

In September Bolivia declared a state of emergency as wildfires burn out of control, which is happening in several South American nations, not only in forests desiccated by the protracted drought, but in the Amazon rainforest and Pantanal wetlands too. NASA published images of the smoke plumes rising from Bolivia as seen from outer space. Back to the Guardian, which intimates that the conflagrations consuming four South Africa nations aren’t the hand of a hot and bothered god but mainly of farmers aspiring to clear land for livestock grazing and to grow soya beans. Guys: no planet, no soybean market.

Fire in Copaibo Forest, Chiquitana, Bolivia September 26, 2020Credit: EDWIN PYNEGAR/REUTERS
Smoke plumes rising above the PantanalCredit: AMANDA PEROBELLI/REUTERS

Archaeology, hominin evolution and thou

By the way last week the press brimmed with reports that climate change has led to hominin migrations, and even help kill off other human species. Nu. If the environmental conditions deteriorate, it’s obvious that anybody who can and who thinks of it, will leave. Whether they go in the right direction is another matter. Now think of this: We generally only know about the migrations that succeeded, where the people moving en masse managed to reestablish themselves and leave traces. But a migration is only an option if there’s somewhere to migrate to. Dear reader, where are we supposed to go as widening swathes of this Earth become uninhabitable? With that in mind, vote appropriately.

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