Showing posts with label plankton. Show all posts
Showing posts with label plankton. Show all posts

August 13, 2015

Don't forget the plankton

I’M READING A BOOK about one of the most fascinating stories of survival at sea in a small boat, one that ranks right up there with Captain Bligh and Shackleton and Survive the Savage Sea.

It’s called All Brave Sailors, by J. Revell Carr (Simon & Schuster), and it deals with the sinking of an English tramp steamer, the Anglo-Saxon, after a surprise attack by a German raider ship (a powerful warship disguised as a neutral merchant freighter) during World War II.

Only seven of the Anglo-Saxon’s crew managed to escape from the sinking ship in a clinker-built 18-foot open gig. They had practically no food, just a few gallons of water, and no navigation equipment apart from a compass.

Of those seven, only two survived a 70-day sail in the gig from the eastern side of the North Atlantic to Eleuthera Island in the Bahamas, where they became instant celebrities.

They ran out of food and water fairly quickly, and a large part of the book explains how their ravaged bodies coped with the situation. What strikes me, however, is that they made no attempt to catch plankton, an act which surely would have saved more lives.

Dr. Alain Bombard demonstrated the abundance of life-giving plankton in his Atlantic crossing in his raft, L’Heretique. Before that,  William Beebe, the famous naturalist, writer, and explorer, undertook the laborious task of counting the number of the tiny creatures he caught in a net. Here’s his account, from The Arcturus Adventure (G. P. Putnam’s Sons):

“One dark moonless evening I put out a silk surface net, the mouth of which was round and about a yard in diameter. At the farther end of the net a quart preserve jar was tied to receive and hold any small creatures which might be caught as the net was drawn slowly along the surface of the water. This was done at the speed of two knots and kept up for the duration of one hour.

“When drawn in, the net sagged heavily and we poured out an overflowing mass of rich pink jelly into a flat white tray."   

Most of the these individuals were primitive crustaceans, which make plankton a rich, nourishing food, even raw.

It’s also worthwhile repeating that all these creatures that we call plankton were caught at the surface on a dark night. Beebe repeated the experiment in full daylight and caught only about 1,000 individuals instead of 40,000,000.

“Plankton will have nothing of the sun or even of moonlight,” he observed, “and remains well below the reach of the stronger rays.”

You might want to try dragging a net, or even a shirt sleeve knotted at the end, next time you’re at sea on a dark night. You never know when this knowledge might come in useful.

Today’s Thought
Shipwrecked men in an open boat, if their lot is cast on waters rich in plankton, never need to starve to death if they can manage to drag an old shirt, net, fashion, through the water at night. — William Beebe, The Arcturus Adventure

Tailpiece
“How’s your son getting on these days?”
“He just turned 16. He kissed his first girl and started smoking.”
“Wow! Must have been some kiss.”

December 12, 2013

The mysteries of the deep

I WAS REMINDED the other day of how little we know about the sea.  I don’t mean the surface of the sea, but underneath. We know well enough about waves and currents and tides and hurricanes, but  we know very little, comparatively, about what lurks in the depths.

I think it was the naturalist William Beebe who wrote about the unease he felt out at sea, when he could almost feel millions of little eyes looking upward at him, especially at night. He was probably referring to plankton, which he used to catch in a net trawled from the stern of the boat on moonless nights, but I’m not sure about that. Maybe plankton are too small to have eyes, in which case it must have been shrimps or octopuses or the enormous schools of squid that are attracted to any kind of light at night.

Ordinarily, you’d never know they were down there — along with a host of other sea life we know next to nothing about. I can remember sailing along in a nice breeze one pitch-dark night somewhere between Cape Agulhas and Cape Point when two streaks of light came hurtling toward us amidships from starboard.

To say I was startled is putting it mildly.  They were twin tunnels of light apparently intent on boring into our hull at high speed, and my first irrational thought was “Torpedoes!”  Then I realized that the tubes of submerged light were actually phosphorescence created by some things moving about six feet below the surface on a collision course.

At the last moment, while I was still frozen with inaction and fright, they dived under the boat, came up on the opposite, and raced away into the night. I realized then that they must have been dolphins having a bit of fun scaring the human beings.

And now I wonder how many times this happens during the day when we have no tubes of light to alert us to their presence. How often do the creatures of sea approach us and leave no clue of their presence?  It’s impossible to know, obviously, but one can’t help speculating about how many close calls there have been with whales and (even more frightening) the giant squid known as Architeuthis, whose eyes are as large as automobile hubcaps and who grow to 65 feet or more, and who have large poisonous fangs and hundreds of suckers as big as dinner plates, and who have been known to swarm aboard large sailing ships in the old days and drag them and their crews down to Davy Jones’ locker, and . . . well, perhaps I exaggerate a little, but not much.  

It’s enough to keep a person very alert for any sign of tentacles creeping over the cockpit coaming during the night watches.

Today’s Thought
Ye monsters of the bubbling deep,
Your Maker’s praises spout;
Up from the sands ye codlings peep,
And wag your tails about.
— Cotton Mather, Hymn

Tailpiece
Confucius, he say that it’s better to have loved and lost than to do homework for six children.

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)   

November 10, 2013

Hidden treasure of the sea

ONE OF THE GREATEST WONDERS of the sea is the sheer amount of life it sustains, most of which goes unobserved as we plow our way through or over it.

William Beebe, the famous naturalist, writer, and explorer, once undertook the laborious task of counting the number of tiny creatures he caught in a net. Here’s his account, from The Arcturus Adventure (G. P. Putnam’s Sons):

“One dark moonless evening I put out a silk surface net, the mouth of which was round and about a yard in diameter. At the farther end of the net a quart preserve jar was tied to receive and hold any small creatures which might be caught as the net was drawn slowly along the surface of the water. This was done at the speed of two knots and kept up for the duration of one hour.

“When drawn in, the net sagged heavily and we poured out an overflowing mass of rich pink jelly into a flat white tray. This I weighed carefully and then took, as exactly as possible, a one-hundred-and-fiftieth portion.

“I began to go over this but soon became discouraged, and again divided it and set to work on one-sixth of the fraction on which I had first started.”

After many hours of eye-straining and counting under the microscope, Beebe conservatively estimated that his 1/150th part of the hour’s plankton haul came to 271,080 individuals.

“If we multiply this by 150,” he said, “we get 40,662,000 individuals . . . a very conservative estimate.”

Most of the these individuals were primitive crustaceans, which make plankton a rich, nourishing food, even raw.

It’s also worthwhile mentioning that all these creatures that we call plankton were caught at the surface on a dark night. Beebe repeated the experiment in full daylight and caught only about 1,000 individuals instead of 40,000,000.

“Plankton will have nothing of the sun or even of moonlight,” he observed, “and remains well below the reach of the stronger rays.”

In fact, the very word plankton derives from the Greek word for a wanderer — a reference to its habit of migrating upward in the ocean at night, and down during the day.

Today’s Thought
Shipwrecked men in an open boat, if their lot is cast on waters rich in plankton, never need to starve to death if they can manage to drag an old shirt, net, fashion, through the water at night.
— William Beebe, The Arcturus Adventure

Tailpiece
 “They’re such a devoted couple next door.  Every time he goes out he kisses her. Why don’t you ever do that?”
“Why should I?  I hardly know the woman.”

(Drop by every Monday, Wednesday, Friday for a new Mainly about Boats column.)