10 Fascinating facts about Whales

n3bul4 (62)in #life • 9 years ago (edited)

Nowadays, for most of the people, whales are not a huge protein source any more, that is meant to be unscrupulously exploited, but rather soft, smart, gentle giants of the sea. After decades of hunting nearly to extinction, a lot of species have recovered regarding population. Besides some indigenous people, only a few nations still hunt this animals in a big way. Whale research has made rapid progress, but many questions are still unanswered. Why do Cuvier-Whales dive that deep? Why do whales strand? How does the blue whale feed its massive body, and which species are threatened to vanish soon?

Amazon River Dolphin - Whales also feel at home in freshwater

We connect dolphins mostly to saltwater. Certainly, the overwhelming majority of the about 90 known species live in the sea, but a small group managed to adjust to freshwater and exists solely in big river systems in South-Africa and Asia: The Amazon River Dolphin, the South Asian River Dolphin and the Yangtze Dolphin or Baiji, which is known to have almost died out (some other species, like the Irrawaddy Dolphin from Mekong, only visit this living environment sometimes). The most significant characteristic of the River Dolphin is its lengthy, very narrow snout, making them able to adjust to the gloomy water and sight, while searching for food in the mud at the river's ground. Possibly the first River Dolphins developed from species having their living environment at plain coastal waters, about 20 million years ago. From the Amazon Basin there are three well known species, that can be watched relatively easy at big rivers. The Amazonas River Dolphin (Inia geoorensis), is the most popular one and attracts attention with its pink skin. Sad, that fishermen sometimes look on them in a competitive way and try to kill the animal. The flesh often serves as bait for the actual quarry.

Omura-Whale - Unknown variety in the sea

The Omura-Whale is bigger than an Orca, nevertheless marine biologists have overseen it for a long time: As late as in the year 2003, Japanese scientists were describing the Omura-Whale (Balaenoptera omurai) the first time. Before this times, whale-hunters have considered the killed exemplars as small representatives of the Bryde's whale, and since the acknowledgement of its own species, almost no proceedings could be achieved regarding exploration of the Omura-Whale, til Salvatore Cerchio from the New England Aquarium in Boston and his team discovered a population at the northwestern coast of Madagaskar the first time. According to DNA analysis Omura-Whales show relatively small genetic diversity among themselves, so probably they are kind of rare. At least the animals seem to prefer relatively plain and warm shelf water areas, where they are able to filter plankton out of the water. The Omura-Whale is not an exception: In the last decade, a lot of new whale species have been discovered and described. Despite their size they could have been overseen in the widths of the sea, or have been mistakenly related to already known species. Another example is the Beaked-Whale from the pacific, which Japanese whale-hunters call Crow-Whale, because of their dark color.

North Atlantic Right Whale - Collisions are its destiny

The Atlantic Right Whale (Eubalaena glacialis) belongs to the seldom large whales of the Earth. Til now it has been almost unable to recover from having been hunted, by which the former 100.000 animals big population has been drastically reduced: Only about 300 to 500 exemplars are still swimming offshore at the North-american Atlantic Coast. The European population in contrast has died out. In English language the whale has its name from being thought to be the "right" sea mammal, back in the days at the beginning of whale-hunting. These whales where slowly swimming in the near of the coast, and therefore represented an easy catching. Nowadays the biggest danger for this animals is the collision with ships. In the last decades this collisions were responsible for one third of all cases of resolved deaths. Often this animals die, because they get entangled in mooring ropes and nets. Because of the low population, every loss means a setback for species protection.

Sperm Whale – Be careful when they have stranded

In January 2016 several Sperm Whales had stranded at the coast of Germany and Netherlands, although they were healthy, according to autopsy, except of the plastic waste found in their stomachs, which hadn't lead to immediate death, according to veterinarians. It is possible, that the animals got lost while being on their way from the Antarctica into the south, where they didn't have enough food and finally had to die in the flat shelf sea. Basically this strandings can occur world wide. The reasons haven't been entirely resolved, although a lot is being discussed. F.e. that solar storms could influence the magnetic orientation of the animals in a negative way, military sonars fatally disturb their communication, or ill fellows are leading them into doom. Often humans try to bring these whales back into sea, but most of em sadly parish at the beach. This can get dangerous for the helpers, if fermentation gases are blowing up their massive bodies. So far cadavers exploded, like spectacular videos show. Sometimes dead whales are preemptively blown up.

Porpoise – Germany's only whale

In German waters it's seldom that whales bustle. Sometimes sperm whales become lost in the German sea, but they don't make it very long. Also the Finnish and Northern Minke Whale are not often their guests. The Big Tumbler lives in the German sea, but prefers to stay away from the coasts. Totally differently, the Porpoise (Phocoena phocoena), which can be observed from the Sylter Beach when having luck. This is the place where marine mammals reproduce and are raising their children. The overall population is estimated to hold about 15.000 to 50.000 animals, depending on the season. So this species is not acutely in danger. However, Porpoises do face problems in the German sea: They get tangled up in fish-nets and are known to be sensitive to noise. This is why they flee from regions were offshore wind turbines are placed.

Vaquita – A dying breed

At the time of this writing, only about 30 Vaquitas are swimming in the Golf of California and this hint is important, because this species is dying out right now, in front of our eyes: Almost every month one of this small whales dies in a fish-net, which sole purpose is to hunt after a different species endangered by extinction. Every taken countermeasures like fishing bans or protectorates have failed, because law couldn't be enforced locally. According to biologists, the last hope is to take all the Vaquitas to a closed installation, f.e. a closed bay, where they could reproduce. Specially trained Big Tumblers could detect the shy Vaquitas, and lead the animal rights activists to them. In spring 2017 activists plan to spend their money for this experiment up to the last farthing. Let's hope that it won't be too late.

Narwhale – The one with the big tooth

Among mammals the Narwhale (Monodon monoceros) sticks out with a very special feature: his supersized, spiral-shaped tusk which can get as long as 3 meters and juts out of the upper lip. For long time biologists have been puzzled about its purpose. Does it serve as a secondary sexual characteristic, which should convince male whales from its female qualities, or do rivals fight out competitions with it? Is it an organ of perception? Maybe the tooth is something of everything. Drone recordings at the coast in the Canadian territory Nanavut show, that it serves for one thing at least: The animals use it to overpower potential prey. A short snappy movement makes the enemy of the Narwhale unconscious, making it easier to catch.

Blue Whale – How the giant subsists

Blue Whales (Balaenoptera musculus) can reach a length of more than 30 meters and a weight of up to 200 tonnes. This makes them the biggest animal species that has ever lived on Earth according to our knowledge. This massive body has to be fed, which is managed almost only by eating tiny organisms: Plankton, krill, and very rarely fish. Calculations show huge amounts of 40 Million of this small animals being eaten by a Blue Whale daily. Around 3.5 tonnes of food. But how does such an animal manage to exterminate that immense amount. The opening of its mouth lets the whale slow down, while getting water and food poured in. On every attempt its mouth fills with water masses corresponding to about the half of its body weight, filtering nutrients and crustaceans, while letting the water flow back into the sea. All this is happening in a very energy efficient way: With every bite the whale takes 90 times more energy compared to the amount he needs for the eating process and the following acceleration of his body. To decide whether the swallow is worth it or not, the whale owns some highly sensible sensors in his snout, with which they are able to measure prey density in the water.

Cuvier-Whale – Nobody dives deeper

As for every mammal, whales and dolphins have to regularly return to water surface, to breath some air. Nevertheless some species manage to dive down into the eternal dark of the deep sea for hunting. The most famous example are Sperm Whales, that even face big octopuses, representing their main food. According to current knowledge, the record regarding diving holds the Cuvier-Whale (Ziphius cavirostris), which can get up to 7 meters long and up to 3 tonnes heavy. With the help of the satellite system ARGOS, Gregory Schorr from the Cascadia Research Collective and his colleagues, could prove that the longest measured dive has taken over 2 hours reaching as deep as about 3 kilometers. Biologists suppose, that the Cuvier-Whale hunts for octopuses, but very little is known about their hidden live style.

Bowhead Whale – As old as Methuselah

High up in the north the Bowhead Whales (Balaena mysticetus) are living, that have some special characteristics: The head takes up about one third of the whole body length, their layer of fat is very thick to be able to adapt to cold water temperatures, and they get very old. There are known examples of Bowhead Whales with more than 200 years live time. This makes them the most long-living mammal on Earth. Only a few of the vertebrates outperform the Bowhead Whale, f.e. the Greenland shark, which gets as old as about 400 years. Because of their productive bubbling and the easy way to hunt them, most of the victims of industrial slaughter can be found under the Bowhead Whale. But slowly their population is growing: Today there should be about 5000 to 8000 exemplars. In a small amount the Inuit are allowed to hunt these animals traditionally. The predominant majority of Bowhead Whales live in the Pacific.
The Atlantic population was thought to be dead for a long time, but maybe a small amount has survived. In the middle of a long unknown safehold between Greenland pack ice ...

Images from: Getty Images / iStock / Salvatore Cerchio, New England Aquarium and Woods Hole Oceanographic Institution