Here at HTHT, we teach a LOT of science, and the best part about it is feeding young scientists’ curiosity about this amazing world we live in! Although our programs are jam packed with experiments, we make time to let our young scientists ask us whatever questions they’ve always wanted to ask a scientist.
In the coming weeks, we will be sharing a special series of articles answering some of the most frequent questions that come up from our young partners in science. Our question this week is:
WHERE DO WHALES GO WHEN THEY DIE?
This most excellent question was proposed by a concerned young scientist who had watched some videos of humans dealing with whales that had washed up dead on the shore. In these videos you can see huge whale carcasses, bloated like balloons from the gases that naturally happen when something is dead and decomposing. A huge dead whale that’s stuck on land is a pretty big problem, and, in some famous viral videos, you can see whales on the beach either violently explode from the gases inside, or get exploded with DYNAMITE by people trying to get rid of them. As you can imagine, this is really, really messy!
Much to our young scientist’s relief, I was able to explain that, lucky for us, whales do not usually go to the shore to die. Humans conducting a funeral for an explosive dead whale is actually pretty rare, and is not a problem humans have to constantly deal with. Nature has a much better solution. It’s called a WHALE FALL!
When a whale dies, its body begins to decompose. This means the tiny microbes in and around the whale’s body begin to break the body down, and this process produces gas. LOTS of gas. Plus, the blubber in a whale is full of oil, which also floats. A dead whale becomes like a balloon, floating on the ocean’s surface. This might be gross to us, but in the open ocean, it’s like a happy party for everything out there that likes to eat meat. Sharks especially come from many miles to feed on the tasty treat, taking huge bites until they can’t eat any more. After the sharks have eaten as much as they can, the gas in the whale is all released, and the whale parts that are left start to sink.
But the party doesn’t stop there! In fact, the best part is what happens after the whale sinks. When a whale’s body sinks into the deep sea, it keeps falling until it hits the seafloor, which can be very, very far down. After about one mile down in the ocean, it’s very different than the surface. There is no sunlight in the deep sea, which means the tiny photosynthetic plankton that support life at the surface cannot live there. Food is very hard to find in the deep sea. Animals there usually have to scavenge their food from what is called “marine snow.” Marine snow is a constant fall of tiny flakes of dead plankton, bacteria, and poop that comes from the surface above. When you live in the deep sea, ANY food is great, even if it is mostly poop from other animals far above you!
Can you imagine what it is like for deep sea animals when a huge whale falls from above? It’s like winning the lottery! On land, a dead whale is big trouble, but on the floor of the deep sea, it’s a wonderful gift. Instead of having to use dynamite to clean it up, many deep sea species just go ahead and eat every last bit of the whale. It’s a snack that can last for years. It’s estimated that every whale fall provides 2,000 YEARS worth of the nutrients that come from just marine snow alone!
First, big animals that can swim, like large sharks and hagfish, get their turn. They eat every little scrap of meat that might be left on the bones. Then, smaller fish, crabs, and starfish come and rake through the bones and sediment around the whale for tiny crumbs of food left by the bigger animals. Then, bacteria and special bone-eating worms take over the skeleton, drilling deep into the bones to pull out the last of the nutrients inside. When they do this, they release more even nutrients, which can feed even more small animals around the whale. Finally, after several years, when the whale skeleton is just minerals, animals can attach to it like they would to rocks, and live their lives there.
So, science friends, you don’t have to worry about meeting dead whales at the beach. Nature has a much better answer than humans could ever come up with. The energy in a dead whale’s body feeds many, many animals in the ocean. Even though it’s kind of sad to think of a beautiful whale dying, you can be glad that nothing is wasted, and the whale’s body goes on to bring life to other animals for years after it dies.
SOURCES AND FURTHER READING:
Sharks enjoying a dead whale: https://www.youtube.com/watch?v=W2e3GE5M3CY
All about marine snow: https://www.youtube.com/watch?v=BAvQ3t4ueZw
An excellent explanation of whale fall: https://www.youtube.com/watch?v=QxSUsn8H2zs
Marine biologists very excited to discover a whale fall in real time: https://www.youtube.com/watch?v=CZzQhiNQXxU