SEA STATESMEN

Written by Mark Young

What comes to mind when you think of Benjamin Franklin? We know him as a statesman. One of our founding fathers, he helped frame and then signed the Constitution. He was a prolific author, a printer, an inventor (the furnace stove, bifocals … a carriage odometer?), political theorist, satirist and a philosopher. He formed the first lending library and fire department in Pennsylvania, published and wrote Poor Richard’s Almanack and The Pennsylvania Gazette, and had a major role in founding both the University of Pennsylvania and Franklin & Marshall College. Not bad for a guy whose formal schooling ended at the age of 10.

But your first thought might be the image of Franklin flying a kite during a thunderstorm; he was also a scientist (or, in his day, a natural philosopher). What many people don’t know, however, is that Franklin was also an early oceanographer. He became that by way of his position as deputy postmaster general of North America. It started with a question posed by the English Postal Authority. How, they asked, can American postal ships make the journey back from England to the colonies sometimes weeks faster than the English mail ships. Franklin consulted his whaling captain cousin, Timothy Folger. He learned of an ocean current that American and Spanish ship captains were aware of. They knew to sail with it traveling to England and stay out of it when returning to the colonies. The English mail packet captains were sailing dead against it.

It took years of blank stares before the British followed Franklin’s advice about navigating the current, but that’s another story. Franklin became intrigued by the idea of a “stream” existing in the ocean. During his trips between the colonies and England he took measurements and notes about the water temperature, currents, water color and Gulf weed content. He knew that the current carries warm water from the south to the north, and that his measurements would mark the location of this “river in the ocean.” He also gathered data from Folger and other ship captains, learning enough to chart the Gulf Stream, and giving it the name by which it is known today. It’s a hoot that the first map of the Gulf Stream, published by Franklin in 1768, so closely mirrors today’s satellite images.

Franklin was by no means the first oceanographer. Although it is one of the newest fields of science, formally dating to organized expeditions in the late 19th century, oceanography can be traced back tens of thousands of years to the earliest seafarers who began observing the waves, tides and currents that carried their boats. Oceanography has essentially evolved from the need to find fish along coastlines, past the discovery that the Earth is not flat and can be navigated, past Franklin’s observations about currents, to today’s need to understand the place of the oceans in global climate.

The history of oceanography is as interesting as the discipline itself. In this issue, for our perspective as divers, author Robert Rossier examines what we know about tides, currents and waves, and most of what we know is from the observations made by Franklin and countless others who came before and after he turned his remarkable intellect to the sea.

Franklin’s unique genius was turning his observations to practical use. While the next guy to research electricity with a kite in a storm was killed doing it, Franklin invented the lightning rod. In the same way, the publication of his accumulated oceanographic findings, “Maritime Observations,” contains Franklin’s ideas for sea anchors, watertight compartments, catamaran hulls, shipboard lightning rods, and even a soup bowl that stays in place in rough seas. Oceanographic observation has done much for our lives, and we have benefited as divers — certainly for our ability to understand and continue learning about what we are most privileged to observe.

THINGS WE NEVER KNEW

Written by Mark Young

It takes a drive through Kansas to really understand why it’s called the Sunflower State. In places, sunflower fields extend in every direction, and as far off as you can see. If you have never observed a large field of sunflowers, the sight is awesome beyond the expanse of yellow. You think at first that it’s because the plants are so much taller and larger than you imagined. Then it dawns on you. In stunning symmetry, they appear to be around the same height, and face in exactly the same direction. You may not even realize at first why they are aimed the same way, and that’s the next cool thing. Before they reach full flower, they face the sun as it comes up in the morning and the entire field rotates in grand unison as the sun moves across the sky, to the west by the end of the day. At the top of the Earth, where the sun never sets, scientists have observed sunflowers strangle themselves as they follow the sun circling the rim of the horizon. Any question where the plant got its name?

Even if you don’t know or care anything about sunflowers, this scant bit of information puts them in a whole new light (sorry). It can make you wonder about other things like, gee, what causes them to do that? Do they unwind at night? Do they follow the full moon, too? And even if these few facts don’t make you want to know more, it becomes great trivia for a dinner conversation.

This sidelong example shows that even seemingly simple things can become interesting with knowledge and a few basic facts. Now take something that actually interests us, like diving. As we become better informed the experience becomes more interesting and, in the process, in a way, so do we.

We have entered our 20th year publishing this magazine. There is so much about this activity and its environs to know, for anyone who wants to, and we felt that an educational publication that follows the light was more than needed. So we consider our tenure grateful confirmation that the interest in learning more about diving and what surrounds it is indeed pretty strong. People wondered early on if a magazine themed Dive Training would have enough to write about; there has certainly been enough content.

And it doesn’t run out. There is a long list of interesting dive-related topics that we would like to share with you in this edition, and in future editions. Take jellyfish, for example. We all know what they are but what really gives? This creature is complex in its simplicity. It turns out there is an awful lot to know about jellies, and author Greg Laslo takes us on another tour of a bizarre subject with the cover story that begins on Page 20.

We hope that after reading the article you will never look at jellyfish the same way again. Just like you may never look at sunflowers in quite the same way. So, do they unwind at night? When it comes to pondering what we know and what we don’t, perhaps the best questions revolve around the things that we are interested in and think we know, or never knew, but would like to learn much more about. To help make your diving experience complete, we will continue to keep you in the know about lots of different and interesting topics — lighting interest, we hope, for a few more decades.

EVERYBODY'S BACKYARD

By Mark Young 

European explorers led by Christopher Columbus were actually searching for a sea route to Asia when by luck they discovered the Caribbean and the Americas. This wasn’t so lucky for the various native populations, however; they couldn’t defend themselves against conquest, but the most devastating import was biological. Where the people of the three known continents had long been exposed to each other’s diseases and developed a strong immunity, the cultures that the “Columbuses” discovered were powerless against the import of smallpox, measles and influenza. Mere contact killed millions of indigenous people.

In a sense you could say that throughout history subsets of man have been an invasive species. And wherever we humans have gone, nature has been along for the ride. 

People tend to think of “invasive species” only in negative terms, but the phrase has several degrees of definition. Toward the “OK” scale it refers to “introduced species or nonindigenous species that are rapidly expanding outside of their native range.” A not-so-OK connotation is, “alien species whose introduction or spread threatens the environment, the economy, and/or society, including human health.”

Degrees of the definition are appropriate. For example, an argument can be made that the introduction of most exotic species has richly enhanced biodiversity. Consider traveling plants; more than 4,000 species introduced into North America during the past 400 years make up nearly 20 percent of our current plant biodiversity. And, with no evidence, according to some biologists, that a single resident species has been driven to extinction. In other words, with some pesky exceptions, plants that invade fit in. 

As divers we tend to think negatively about the arrival of nonindigenous marine life, yet the opening of the Suez Canal in 1869 introduced 250 new fish species into the Mediterranean from the Red Sea, reportedly resulting in only a single extinction. So there’s that. 

On the other hand, who wants the Burmese python at the top of the Everglades food chain? (Have you seen the YouTube video of the snake that exploded while digesting an alligator?) Their numbers in the Glades are estimated at more than 100,000, growing fast, and pose a threat to natural balance in a truly spectacular ecosystem — all because a few pets outgrew their welcome. Perhaps the Nile monitor lizard, an African heavy that grows to 7 feet (2 m) in length can give the pythons a run for the top; they’ve also established Florida residency. Kind of makes the U.S. invasions of zebra mussels and Asian carp seem tame.

This month’s cover feature is an update on the Atlantic/Caribbean invasion of lionfish, another pet let loose. There’s no debate that this has the possibility of an environmental disaster. One hope against it is the commercial potential of lionfish as a culinary dish; that would at least put something above them in the food chain. Another possibility is whatever mechanism keeps them in check in their far-Pacific homeland, something that is being studied to determine. 

However this plays out, we’re about to see in the extreme how well natural balance can occur where it must, while we humans continue to move nature past the geographic boundaries that once contained the Earth’s biota, and into our own backyards.