By Wendy Williams
The ocean giveth, and the ocean taketh away…
And somehow, over the ages, it has all fit together, most of the time. But just exactly how does this work?
At recent conference in Vienna regarding worldwide feral horse populations, population geneticist Philip McLoughlin discussed his planned research into this mega-question by studying a minuscule island located about 300 kilometers southeast of Halifax, Canada.
Sable Island, now a Canadian national park, is little more than a tentative bump of sand poking, rather precariously, above the North Atlantic. Of course, an island out in the middle of this angry mid-winter sea is a risky place for land-loving mammals.
Yet small bands of horses have been surviving here for several hundred years, left there by a proper Bostonian in the years prior to the American revolution.
How do the horses survive? What can they be eating? Where do they shelter from winter winds?
And what in the world does the ocean have to offer these beleaguered land mammals?
McLoughlin dreams of finding the answers to these and many similar questions over the coming 30 years.
He already has one fascinating theory.
Within the last several years, Sable Island is said to have become the largest seal pupping location anywhere in the north Atlantic. Each summer several hundred thousand gray seal mums give birth to and care for their offspring on the island’s sand beaches. Given that the island is a crescent-shape of only 13 square miles, I can imagine the decibel levels each spring and early summer.
How do the horses deal with all this seal-related chaos? McLoughlin doesn’t know yet for sure, but he has learned that the horses have increased in number since the seals have increased their numbers.
Is this just coincidence? Or is there a connection?
McLoughlin theorizes that nutrients from the ocean are feeding the horses by being transformed via the seals into fecal matter that fertilizes the island and increases vegetation. The increased vegetation, he proposes, may be increasing the amount of forage and perhaps the nutrient content of the forage, which in turn may be increasing the number of foals that can survive….
And so on and so forth.
Sable Island is a small, contained interdependent system of life. It’s perfect for the kinds of interrelationships McLoughlin hopes to study over the coming decades. I’m looking forward to some profound and compelling insights into how we land mammals depend on the sea for our survival.
Wendy Williams, author of “Kraken: The Curious, Exciting, and Slightly Disturbing Science of Squid,” is working on two forthcoming books – “Horses of the Morning Cloud: The 65-Million-Year Saga of the Horse-Human Bond,” and “The Art of Coral,” a book examining the past, present and future of the earth’s coral systems. She is also advising on a film to be produced about the environmental effects of building Cape Wind, America’s first wind farm.