Archive

Posts Tagged ‘marine turtle’

The Magnificent Costa Rica Arribada: Invasion Of Olive Ridley Sea Turtles

September 23rd, 2009 No comments
by Victor C. Krumm

[I:http://phila-airport-parking.com/blog/wp-content/uploads//2009/09/VictorCKrumm1.jpg]

She waited 500 yards offshore in the tropical warm eastern Pacific ocean off Ostional Beach. Only fifteen the olive ridley sea turtle was in a small land that Christopher Columbus had named “Costa Rica”, the “rich coast” 500 years earlier.

The nearly daily afternoon rains of October had ended as the marine turtle waited expectantly. The moon was in its final quarter and, though she did not know why, it was having an effect on her.

A dozen meters away, a second olive ridley sea turtle joined her, followed by a dozen, then hundreds, thousands, and soon tens of thousands, all waiting quietly. For epochs the moon has silently passed its timeless phases that affect the world’s tides-and today it was bringing her ashore this night, just as it had led her forebears to ancestral nesting beaches for more than one hundred million years.

Nature is always magical. Just a few months ago, this turtle was living in the middle of the Pacific Ocean more than 2,500 miles away. And the multitude of sea turtles now alongside her were scattered over more than a million square miles of ocean.

Though food was plentiful far out in the Pacific, something was stirring inside her. She and hundreds of thousands like her felt the same need to return to Ostional Beach. They had to go back to where they had hatched.

Now, as she waited in the soft moonlight, she was ready. Over the thousands of miles she had swum she had been bred by several different males in the clear tropical waters because, somehow, they, too, were being affected by something unseen, a force primeval. It was something so compelling that it had been bringing her species back to the same Costa Rica beach since the days of dinosaurs.

In the tropical night this olive ridley sea turtle was waiting. She had somehow found to the very beach where she had hatched in 1995. We do not know how a Pacific marine turtle finds the exact beach where she started life. There are only a few nesting beaches on earth and they are not very big. Indeed Ostional Beach is only a few hundred meters in length. Now part of Costa Rica’s Ostional National Wildlife Refuge, it is without a doubt the most important olive ridley marine turtle nesting site on the planet. Wonderfully, in 1995, the year this turtle hatched, perhaps as many as 500,000 female olive pacific sea turtles had come ashore to nest here in huge waves. These massive invasions are called “arribadas.”

Unfortunately, our sea turtle’s mother will not join her to nest at Ostional this year even though for the last two decades, she had been part of massive Ostional arribadas several times every year. Not long ago, she drowned in an illegal shrimping net on her way back to the ancient nesting grounds. It was a needless waste since it could have been avoided by the simple use of an internationally required, but typically ignored, law requiring a turtle escape device. Thousands more were destroyed in what is politely called “incidental catch” by long line fishermen who refuse to use larger hooks that would prevent tragedy to this magnificent and ancient creature. And, no one knows how many thousands were killed awfully by eating carelessly discarded plastic bags. And, of course, there has been the ceaseless pillaging of nests: millions of eggs from just a few small, precious beaches.

Of course, the hundreds of thousands of olive ridleys just offshore know none of this. As we look out over the water in the pale moonlight, there are now so many that it almost seems one could walk on their backs for at least a mile. We stand in awe at the sheer magnitude of God’s creation. They don’t know or comprehend that they were on this planet long before there was a Tyrannosaurus Rex. They don’t know that we are waiting for them to come ashore so that when they lay their eggs on this tiny wildlife refuge, men, women, and children will legally raid their nests and take 1,000,000 eggs in return for protecting the rest of the clutches and preserving the species. They only know that this is where they are meant to be.

Then, though we do not know why, it happens. It is as though the same quiet voice that told them to come and provided flawless directions to a tiny sand beach thousands of miles away, the same silent command that demanded they wait offshore, now tells them it is time to come ashore. As quietly as they first appeared offshore, as silently as they gathered for days and weeks, their patience has been rewarded. They begin to come to the beach. A single olive ridley marine turtle is followed by a second, then another and another. Soon there are hundreds, thousands, tens of thousands—even more than that. All on a particular little beach. They come in increasing numbers all night. More arrive in the day. All day, day after day. It is the magnificent Ostional Arribada of Costa Rica. As timeless as the moon itself, it is the spectacular reaffirmation of life itself.

About the Author:

Aldabra Atoll

August 24th, 2009 No comments
by Arthur Anderson

Aldabra Atoll is part of the Aldabra Group, one of the archipelagos of the Outer Islands of the Seychelles. The second largest atoll in the world after Kiritimati, Aldabra is the coraline tip of a volcanic seamount, coming up from depths of 4,000 to 4,500m (13,120 to 14,760 ft). At 34 km (21 mi) long, 14.5 km (9 mi) wide and just 8 in (26 ft) above sea level, the atoll consists of four coral limestone islands forming a circle around a lagoon of 224 sq km (86 sq mi).

The lagoon is tidal loses two-thirds of its waters at low tide. Aldabra was given World Heritage status in 1982 to protect its delicate ecological environment.

Because the atoll is so remote, many of its species of flora and fauna are found only here. The islets and rocky outcrops in the lagoon provide nesting areas for thousands of birds.

It has possibly the largest population of red-tailed tropic birds and the second largest colony of frigate birds in the world. Many other birds are found here also, including the Aldabra flightless rail, the only flightless bird found on any Indian Ocean island.

The Aldabran giant tortoises are, however, the atoll’s most renowned residents, being the last of the giant tortoises which were once spread across the entire region. Commercial exploitation is believed to have rendered all other giant tortoises in the area extinct by the mid-19th century, and very nearly exterminated the Aldabran population. Two species of marine turtle also nest on beaches on Aldabra: the green turtle and hawksbill turtle.

Unlike the nearby Seychelles, the atoll is inhospitable to humans as the limestone has been eroded into sharp spikes and water-filled pits. However, the mangroves support fish nurseries, and the lagoon is home to a wealth of marine life, from black-tipped reef sharks to eagle rays and parrot fish.

For almost a century, scientists have been studying the flora and fauna of the atoll, which is uninhabited other than by those working at the scientific research station.

About the Author: