Whale News: Smaller, Lost, and Found

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Atlantic Right Whales Are Shrinking. Cause: Fishing Gear

Scientists report that over the last 40 years, Atlantic right whales have been growing smaller. The main reason is that they’re getting entangled (caught up in) ropes, nets, and other fishing gear.

Scientists began noticing that 5 and 10-year-old whales sometimes looked like they were only two years old. The researchers decided to compare pictures of the endangered whales taken long ago to more recent pictures.

A photo illustration compares the body lengths of North Atlantic right whales, including two stunted whales born in 2006 and 2011. The dotted lines show the expected length of right whales of the same age if they had been born in 1981 with no history of entanglements, or entanglements of their mothers. Scarring from an entanglement is visible near the tail in D, an 11-year-old right whale. The whales were photographed from crewed aircraft in earlier years and, later, by drone.

They found big differences in size. They learned that an Atlantic right whale born today is likely to be about 3.3 feet (1 meter) shorter than one born in 1980.

The scientists say that most of the drop in size is the result of whales dragging fishing gear behind them as they swim. That leaves them with less energy for growing. One expert compared it to a human walking around constantly carrying a heavy weight.

Entangled right whale. UNC Wilmington spot a 4-year old male right whale, Catalog #4057, entangled in heavy fishing rope while conducting research for the U.S. Navy 40 miles east of Jacksonville, FL.

Mother whales that are entangled are also likely to give birth to smaller calves.

Only about 400 Atlantic right whales are left, and they face several other threats. The researchers say these animals need protection as quickly as possible.

Gray Whale Travels Halfway Around the World, Sets Record

In 2013, fishermen in Namibia reported seeing a Pacific gray whale. That was unusual because Pacific gray whales live on the other side of the world from Namibia.

When scientists investigated, they found that the whale’s DNA matched DNA from a group of endangered Pacific gray whales. Only about 200 of these whales are still alive and they live in the far north, near eastern Russia.

Gray whale (Eschrichtius robustus) breaching.

That meant that the whale had traveled at least 12,430 miles (20,000 kilometers), and possibly as far as 16,777 miles (27,000 kilometers), depending on the path it took.

Since these whales normally only migrate about 5,000 miles (8,000 kilometers), the scientists believe the whale was probably lost. It may have been confused by the melting Arctic sea ice, which could be allowing whales to travel in waters they don’t normally visit.

Gray Whale spouting in California.

Bomb Detectors Help Find Group of Pygmy Blue Whales

Since 2002, special underwater microphones called “hydrophones” have been set up in the world’s oceans. The hydrophones are used to detect if any countries test nuclear weapons underwater.

Now, researchers have used recordings from these hydrophones to locate an unknown group of pygmy blue whales.

Even though they’re the smallest kind of blue whales, pygmy blue whales are still huge – about 79 feet (24 meters) long. They’re seen much less often than many other whales. They live far from land and don’t often break the ocean’s surface.

Blue whale

But blue whales have strong, low-pitched songs that can travel for up to 310 miles (500 kilometers) underwater.

Scientists knew that there were four large groups of pygmy blue whales in the Indian Ocean. They had also detected a whale song among all the noise recorded by the hydrophones.

Long-term spectrogram of audio from the Chagos Archipelago with the songs of the new population of pygmy blue whales outlined in black.

When the scientists carefully studied the whale song, they realized it was a pygmy whale song – but unlike that of any known group. It had to be a new group of whales.

The scientists don’t know exactly how many whales are in the group, but based on the number of calls they’ve found, they believe the group is quite large.


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