#TaijiTuesday – Striped Dolphins

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The 2017/2018 Drive Hunt Quota allows for 450 Striped Dolphins

The striped dolphin is extremely active at the surface, performing amazing acrobatics, including somersaults, back somersaults, upside down porpoising, and breaching with leaps three times its length.

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The striped dolphin body size and shape resembles the short-beaked common dolphin, but the colour pattern is unique; its dorsal side is bluish grey to brownish grey, with a white to pinkish underside. The most recognizable feature is a stripe running from the dark beak, above the eye, across its flank and down to the underside at the rear of its body. A second pronounced stripe runs below the eye to the pectoral flipper. It may or may not have a black patch around each eye.

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Striped dolphins travel in groups, typically numbering from a few dozen to 500 animals, but herds numbering in the thousands are sometimes reported. When swimming at high speeds, as much as one-third of a pod will be above water at any given time. Striped dolphins are curious animals and will also often bow-ride, sometimes approaching from a distance. In the wild they can occasionally be seen associating with common dolphins, however confusion over identification can be avoided as the species-specific colouration and markings are easily distinguishable; the striped dolphin does not possess the yellow hourglass pattern found on the common dolphin.

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Striped dolphins are widely distributed throughout the world’s oceans and tend to prefer offshore waters in temperate and tropical zones. Striped dolphins feed mostly on small fish, such as cod or lanternfish, and small squid.

The largest threats to striped dolphins are bycatch in fishing nets, and intentional hunts. Conservationists are also concerned about the long-term impact that pollution, habitat degradation, and prey depletion will have on populations and although the IUCN provide a population estimate of approx. 2 million individuals, and list them as of ‘Least Concern’ (2008), certain populations may be more at risk than this might imply.

Video: Striped Dolphins in the Mediterranean Sea

In Taiji:

A drive of Striped Dolphins into the Cove will either result in slaughter or captivity and sometimes it may be a combination of both. Dolphins will be selected for captivity based on age & sex. Hunters and trainers will also look for dolphins that do not have any scars.

How do they capture dolphins, what happens during a dolphin drive? 

Before sunrise, about 26 fishermen board their 13 motorized boats and head out to deep water where the dolphins migrate. The dolphins have been using these migratory paths for thousands, perhaps millions, of years, and the hunters know exactly where to find them.

When a school of dolphins swims by, the fishermen position their boats one behind the other, perfectly evenly spaced. Then they lower several stainless steel poles into the water, one on each side of each boat. The poles are flared out at the bottom much like a bell, which amplifies the sound produced when the hunters repeatedly hit the poles with hammers. The noise creates a wall of sound underwater, and the dolphins suddenly find themselves trapped between this wall of sound and the shoreline.

In an attempt to escape the sound, the dolphins swim in the opposite direction, toward the shore. The dolphins’ panic and with the loss of their navigational sense, the fishermen can drive them into a small, hidden Cove near Taiji harbor. The fishermen seal the mouth of the Cove with several nets, and the dolphins are trapped.

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Why don’t the dolphins jump the nets?

I hear this question many times, and understandably so. When standing at the mouth of the killing cove in Taiji, you often looked down at a school of dolphins trapped in the killing cove. From above, it’s obvious that all the dolphins have to do is jump the nets, and they would be out of harm’s way. But the dolphins don’t have this advantage of seeing everything from above. They don’t know what’s on the other side of the nets.

To us, a jump would be a leap into safety. To them, it’s a leap into the unknown. It’s also important to keep in mind that nets and other artificial boundaries are foreign objects to wild dolphins. Living in a three-dimensional world, the only boundaries they know are the shoreline and the ocean’s surface. These are a natural boundary that dolphins understand. A net, on the other hand, is completely unfamiliar to them. They are probably afraid of this strange phenomenon and therefore stay away from it. Dolphins in captivity have to be trained to jump over things – it is not a natural behavior.

 

 

 

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