Balance of nature: importance of ocean ecosystems (Introduction)

by David Turell , Sunday, October 18, 2020, 21:43 (1283 days ago) @ David Turell

Another ocean migration system at the basis of ocean food supply:

http://oceans.nautil.us/feature/625/the-earth-shaping-animal-migration-no-one-ever-sees...
"Each night, as the sun goes down behind the horizon, a tidal wave of life rises up out of the deep ocean—everything from crustaceans smaller than a grain of rice to see-through jellies, blood-red squid, and gigantic, boiling schools of glow-in-the-dark lanternfish.

"They’re cold. They’re ravenous for surface-living plankton. And they’re on a tight schedule. For as soon as the sun returns, all these creatures must once again descend back to the black, lest they get gobbled up by the hungry mouths that patrol the ocean’s surface in the light of day.

"This dance between light and dark, warm and cold, and predator and prey is called diel vertical migration (pronounced dial). It’s believed to be the largest movement of animal mass on earth.

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"The depth at which phytoplankton can still undergo photosynthesis is determined by things like water clarity, says Philip Hosegood, a physical oceanographer at the University of Plymouth in the United Kingdom. And water clarity is the result of a whole host of other variables, such as water temperature, wind speeds, tides, currents, salinity, and light.

“'The ocean is a three-dimensional place,” says Hosegood. “But really, of course, it's four-dimensional, because instead of just changing horizontally and vertically, it also changes in time.”

"The lengths to which extra-tiny organisms go to make this migration is also made more impressive with a little knowledge of fluid dynamics. Otters, octopuses, and even humans can glide through water with relatively little resistance, but as a creature gets smaller, the more difficult it becomes for it to overcome water’s natural stickiness.

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"When all those tiny phytoplankton undergo photosynthesis at the surface, they consume carbon dioxide, says Helm. And then when they are eaten, that carbon is dragged back down below.

In fact, when scientists created a model in 2019 to determine just how much carbon DVM is responsible for depositing in the deep sea, they learned that all those squid, fish larvae, and baby shrimp push around 1 PgC—1 petagram of carbon, equal to 1 billion metric tons—into the depths each year.

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"DVM only accounts for about 16 percent of the carbon captured by the ocean, says Archibald. Other contributors include natural water movements, sinking phytoplankton cells, and plain old poop, which at oceanic scales is a vast phenomenon indeed—and of course one supported by DVM’s bounty. DVM also accelerates the rate at which digested nutrients travel. Some research suggests DVM shuttles nutrients downward at an order of magnitude faster than they could sink on their own, allowing them to reach the deep ocean rather than drifting interminably.

"This means that creatures who have never seen the sun still depend on its processes up above. We’re not all that unlike them, actually. For though we live out our days far away from all of this action, the vertical flow of life puts food on our tables and plays a role in our rapidly changing climate. "

Comment: All ecosystems are about food supply, and they have existed and been self-organizing since the start of life. That is why we have the huge bush that now supports a human population currently reaching toward eight billion folks. When I was very young There were only two billion!! Growth exponentially. It is easy to see that God knew all this would happen when we took control of the Earth and the bush of life He provided is thus explained.