Would you believe bird poop holds a key to the health of our oceans?

By Anders and Beverly Gyllenhaal

The sheer magic of seabirds hit us as soon as we reached a mixed flock of petrels and shearwaters gathered in the Gulf Stream far off the Atlantic coast a few years ago. They seemed half-bird, half-fish, swarming overhead, plunging deep into the ocean to feed, skipping over the water’s surface to take off again.

But what’s most impressive about these birds sits out of sight – hidden beneath the waves and on the remote islands. Scientists are now uncovering a phenomenon they call the “circular seabird economy,’’ a vast natural cycle in which seabirds act as couriers, ferrying nutrients across oceans and islands that help sustain the seas themselves.

From albatrosses to petrels, puffins to terns, seabirds spread massive amounts of guano that fertilize the oceans, islands and coastal areas. The guano acts as an all-purpose remedy, reviving coral reefs, strengthening fisheries, feeding the flora and fauna and balancing the seas that cover seventy percent of the Earth.

“These are endangered species that most people never even see, but they’re having huge impacts that affect people,’’ explained Dr. Holly Jones, an ecologist at Northern Illinois University and lead author of the study. “They’re having impacts on vast scales.’’

Extraordinary nature of seabirds

Our trip into the Atlantic’s Gulf Stream was a reminder of how hard it is to even get a look at most seabird species. It took all morning just to reach the deep water where the birds gather. We were writing about the extraordinary nature of seabirds (here’s that post): how they spend most of the year on the open water; fly thousands of miles at a time (some while sleeping); and come to land just once a year to breed.

So we were fascinated by this fresh scientific research that delves into a whole new dimension of seabirds – and makes the case for why we should be doing whatever possible to protect them.

“Seabirds are the major engines that drive these ecosystems that don’t have a lot of nutrients available to them,’’ said David Will, director of impact and innovation at the nonprofit Island Conservation and another of the 15 co-authors of the study. “They are one of the major ways that important nutrients, like nitrogen and phosphorus, are delivered out onto these islands and seas. And those have all these cascading benefits to the ecosystem.’’

Here’s a graphic, courtesy of the study’s authors, that shows the basics of how the cycle works:

One of the themes of our book, “A Wing and a Prayer: The Race to Save our Vanishing Birds,” is the outsized role birds of all kinds play in the balance of nature. The seabirds are a vivid example of exactly how they do this. As Professor Nick Graham of Lancaster University, another of the paper’s co-authors, put it: “They quite literally feed life from ridge to reef.”

And seabirds themselves are treasures, since they tend to be among the rarest birds from corners of the world that supports many one-of-a-kind species. “Island ecosystems are often where we find amazing diversification and very amazing species,” said Dr. Donald Lyons, director of the Audubon Seabird Institute. “Many of these animals and plants occur nowhere else.”

Helping birds helps ourselves

A big part of the new research focuses on what it takes to protect seabirds. Like a majority of the world’s avian species, seabirds are under intense pressure. The world’s 300 plus seabird species are estimated to have lost 70 percent of their populations over the past half century, which ranks them among the most threatened group of birds on Earth.

Among the primary causes are invasive predators, including rats, feral livestock, mongooses and mosquitoes, that have overwhelmed the majority of the world’s islands. They attack birds, their eggs and their fragile biology to the point that birds have vanished from many islands.

Hundreds of conservation projects to remove these predators, or in some cases fence them off from breeding grounds, are now underway on about 1,000 islands, and they’re showing encouraging results.

Several species of seabird thought to be extinct, including the Black-capped Petrel, the New Zealand Storm Petrel and the Bermuda Petrel, have been rediscovered and are now the targets of intense conservation and research.

One of David Will’s favorite examples of dramatic progress is on the tiny island of Desecheo near Puerto Rico, where seabird populations that once darkened the skies had been completely lost to predators. Within a year of removing the feral goats, rats and cats over the past decade, the seabirds began to return. “We’re moving toward those clouds of seabirds again,’’ said Will. “It gives me hope we’ll see more and more places where we can turn the tide.’’

Maine’s Project Puffin is among the most impressive and innovative conservation effort for seabirds. The beloved birds with striking orange beaks and cartoon-like faces vanished from the state due to hunting over two centuries. In the 1970s, the Audubon Society’s Seabird Institute began transporting chicks from Canada on three islands along the coast, and used mirrors, decoys and audio recordings to convince other puffins they had lots of company on the mostly vacant islands. Today, between 2,500 and 3,000 of the birds are thought to be breeding along the Maine coast. (Watch for our upcoming post on seabird conservation that goes into more depth on this project.)

Scientists can’t yet say whether the long and steady slide in seabird populations is slowing or even beginning to reverse. It’s a challenge made especially difficult by the enormous breadth and remoteness of seabird habitat around the world.

But innovative conservation and advances in technology can now watch over the birds with the use of electronic tags, satellites, drones, sound recordings and remote cameras that enable researchers to reach every corner of the globe. These make it possible to study population trends from afar, sometimes without ever visiting the islands, which multiplies the impact scientists can have.

Next: Our second post on seabirds coming soon will look at how these advances are changing the outlook for both research and bird populations for some of the world’s most endangered and important species.