All life requires water. I submit to you that water is our planet’s blood. When we look at a river delta, is it not a pattern we have seen before? Our body’s circulation system of arteries, veins and capillaries – or the circulation system of a leaf, the branches of a tree, or its root system. How about the wing of a monarch? All these are circulation systems. The living tissue of our body requires a healthy blood flow. And so does our living planet. The ocean’s circulatory system supplies food to the entire ocean, and the entire world!
Imagine that you are a rain drop. You just fell to the earth in Canada. Prior to that, you lived in the Atlantic Ocean. Heated by the sun, you turned to water vapor and became part of a huge hurricane. The cloud you were in eventually traveled north where you turned to rain and dripped off the horn of a moose before entering a peat bog. Fish swam with you. A muskrat carried you onto the bank where you sank into the soil before slowly finding your way back into the bog. A frog drank you, but before long, he was eaten by a heron, which flew to a nearby lake. The lake was full of lily pads, and for a season, you were part of one of them. Frogs used you to move from place to place, dragonflies rested on you in the sun. In the fall the leaf died and you again were part of the lake. You have been in a fish eye, a crawdad’s claw, and even part of a raccoon’s paw.
In the fullness of time you have been a part of all things living. On your way from one form to another you have been mist, dew, sleet, hail, frost, vapor and breath. You have been steam, helped boil an egg, been dog slobber, cat spit and baby drool. You have been part of a mud puddle, in a swamp, been part of a smelly wet sock, and spent the winter in an icicle.
From the beginning of time you have been in, through, part of, or used by virtually all life on the planet. Right now, you just went over the beaver dam of the lake, and are flowing south in a clear running stream. Farther and farther the stream carries you. The stream enters the Ohio, and further down, the mighty Mississippi. The water deepens. On you move, the river carrying you south. Before long the water begins to get salty. You have been here countless times before; the circulation system has once again returned you to the ocean.
The fresh (more buoyant) water you are part of does not immediately mix with the heavier saltwater of the ocean; instead, it stays in a layer on the surface. Soon, you feel the warming rays of the sun, and photosynthesis turns you in to a microscopic plant called phytoplankton. The water all around you begins to turn green as more and more phytoplankton come to life. Phytoplankton are so plentiful that they produce over half of the planet’s oxygen. With the proper nutrients (like those brought from the river) they come to life in numbers so vast we cannot comprehend. They are the most basic building block of the planet’s food web, and without them, all life on earth would cease to exist.
The word plankton means free floating, which means you can’t swim! You just drift along with the ocean current, making oxygen, until you get eaten by another type of plankton – in this case, the smallest animals on the planet – zooplankton. Krill (one of the many zooplankton) are very small shrimp-like creatures; but they are so plentiful that whales live by eating them. Zooplankton are also essential to the food web, as they are just the right size to be eaten by the smallest marine life in the ocean.
It isn’t long before you get swallowed by a fish, and moments later, it gets eaten by a shark. For a while, you are in the dark, but in time you get digested and find yourself in new water. It’s colder here, and quieter. The water is so deep you cannot see the bottom. There is such a strong current that at first you think you are back in the river, but a sea turtle makes it clear you are still in the ocean. Colder and colder the water gets. Soon icebergs become part of your scenery. The current continues to pull you north. The water is so cold you feel you will certainly freeze solid. But today, at least, that is not your fate. As the water turns to pure ice all around you, leaving the salt behind, you find yourself in water that is more and more salty. The increased salt you now carry makes you much heavier and keeps you from freezing. Soon you are surrounded by icebergs, and you have become part of a thick super-cooled brine solution that is dripping through the icebergs to the endless dark fathoms below. You have become like an anchor, and are sinking straight to the bottom.
In time, you touch down on an under-sea mountain, and immediately begin to flow downhill. Moving along in the dark, you are part of an under-sea river. Blackness surrounds you; days become months, and years, and then centuries. The under-sea river carries you east in the deepest waters of the ocean. Over 1200 years pass. But one day you begin to feel yourself start a rapid climb off the bottom. You begin to see glimmerings of light, and the water seems a bit warmer. As your world is once again illuminated, you know you have been here a thousand times before. Looking around you see that the river you are in is full of food! Flowing deep below the ocean, the river has brought back to light particles and minerals which will feed a new crop of plankton.
It turns out that the salt left behind by water turning to ice at the earth’s poles, creates a thick brine which sinks like a rock to the bottom and flows like a river – it is the salt in the water that causes the ocean to circulate. What an amazing design.