There are different populations of blue whales worldwide, and each can be identified by its own whale songs.
A new population has been identified based on its unique whale song, recorded in three locations: the Arabian Sea coast of Oman, the Chagos Archipelago in the central Indian Ocean, and Madagascar in the southwest Indian Ocean.
This discovery was reported in the journal Endangered Species Research.
We asked our contributors what their favorite marine mammal dive was and they sent us tales and images of magnificent whales, playful seals, endearing sea cows and curious dolphins.
Currently, there are only 400 of these whales left in the wild.
The first calf was seen on December 4, near Cumberland Island, Georgia. Then, on December 7, the second calf was spotted swimming alongside bottlenose dolphins off Vilano Beach, Florida.
When whaling all but exterminated the Antarctic blue whale 50 years ago, the waters around South Georgia fell silent. Between 1998 and 2018, dedicated whale surveys off the sub-Antarctic island yielded a sole blue whale sighting. But a whale expedition this year and analysis by an international research team resulted in 58 blue whale sightings and numerous acoustic detections, raising hopes that the critically endangered mammal is finally recovering five decades after whaling was banned.
It’s been a quiet summer in the waters of Alaska.
With zero cruise ships carrying whale-watchers and glacier gazers—a situation which temporarily boosts the state’s population of 730,000 by 1.4m individuals—the humpback whales in the vicinity have grown much more talkative.
This is the impression that delighted researchers are getting.
Slipping softly into the water, I had a straight path to the mother and calf that were resting near the surface only a short distance away. We closed the gap as quietly as a group of excited first-time whale watchers could manage and were rewarded with an initial glimpse of humpback whales from under the water. The newborn stayed close to its mother and swam up and over her rostrum as we looked on.
Every summer, East Australian humpback whales migrate from the feeding grounds in Antarctica to their breeding grounds in the Great Barrier Reef. They remain there for about several months, before making their way around the southern Australian coast back to Antarctica for the winter.
This scenario may one day become reality. And to be efficient, such robots would need to be maneuverable and stealthy, and be able to closely mimic the movements of the marine creatures.
Scientists like Keith W. Moored are working on the next generation of underwater robots by studying the movements of dolphins and whales. "We're studying how these animals are designed and what's beneficial about that design in terms of their swimming performance, or the fluid mechanics of how they swim."
In November 2016, a 7.8 magnitude earthquake in New Zealand triggered underwater mudslides in the underwater canyon off the coastline. This led to high-velocity currents to flush 850 tonnes of sediment from the canyon into the ocean.
This "canyon flushing" caused what was once a diverse ecosystem of invertebrates along the Kaikoura underwater canyon to become as "quiet as a desert."
After studying 186 live strandings of healthy gray whales from 1985 to 2018, researchers at Duke University concluded that whales' navigational sense is affected by solar storms taking place as far away as our sun.
The researchers based their findings on the fact that the strandings are more likely to occur on days when there are more sunspots. Linked to solar storms, sunspots represent sudden releases of high-energy particles from the sun. These may disrupt magnetic orientation behaviour when they interact with the Earth’s magnetosphere.
