We all have our weird quirks. Me? I'm fascinated by dead whales.
Okay, it's not as morbid as it sounds. I've always loved whales (alive ones), and they were the highlight of my fishing trips to Resurrection Bay.
It took until I was 25 to realize that these magnificent creatures eventually had their own mortality to deal with...and yet, in all of my time out on the ocean, I had never seen it myself. So what was happening behind the scenes?
One Google search later, I found a whole world under the waves I had never known.
What happens when a whale dies?
When a whale passes, its body starts decomposing from the inside out. This leads to the release of gasses that keeps the body buoyant on the surface for some time. The body bloats and floats, sometimes to alien-esque proportions.
For critters in the epipelagic zone, this offers the opportunity of a lifetime. You'll often see sharks feasting on the nutrient-rich blubber (which can lead to some scary encounters, if you venture too close!)
Soon after, those gasses release, and the animal will start to drift deeper into sea, sinking mile by mile until it eventually lands on the sea bed.
What Is A Whale Fall?
When the body of a whale eventually settles on the ocean floor, this "whale fall" brings transforms every inch it touches. The once-scarce seabed is suddenly infused with a massive source of food, which attracts visitors of all varieties. Hagfish, sharks, crabs, sea snails, bristle worms, and even octopuses can feed on the whale for years, stripping away the blubber and flesh still remaining.
These scavengers don't get all the fun, though. Scientists have found "zombie worms" (osedax) on skeletal whale remains. These bone worms bore into the bones to feed on the rich lipids, breaking them down until there is nothing left. This was the first--and one of the only--places that we see Osedax in the wild!
Whale falls lead to an explosion of biodiversity. All that energy creates a domino effect that lasts for decades after the whale's first touchdown. We still don't understand how deeply the local ecosystem feels that impact, since we rarely find natural whale falls in the wild. How many must be out in the unexplored portions of the deep sea, just waiting to be discovered?
How Whale Falls Impact Climate Change
Let's be honest; I was looking for an excuse to write about whale falls. So why now?
Well, there's been a lot of talk about whales this week. For one, we learned that whales eat way more than we initially thought. We've also seen how whale excrement--one of the most iron-rich material in the ocean--brings vital nutrients to otherwise barren zones of the ocean, which helps critters like phytoplankton, the backbone of the marine food chain).
We have also learned more about how whales impact climate change. As it turns out, whales take up a LOT of carbon. Over their lifetime, they accumulate literally tons of carbon in their biomass, which takes to 33 tons of CO2 out of the atmosphere for good. The animals then die and return that carbon slowly back into the deep-sea ecosystem.
Whale falls are the last step in a cycle that attenuates carbon on a global scale. When done right, this process yields an abundance of life. Unfortunately, things have been getting in the way; namely, us.
Whaling left a gruesome mark on the oceans, including the loss of these massive animals. Thousands of carbon-sequestering powerhouses were ripped from the depths, and those deaths didn't even return nutrients back into the ecosystem.
Whaling may not be as popular today, but the danger isn't gone completely. With warming oceans, underwater noise pollution, and habitat degradation, whale populations around the world are under threat.
That's not to say there isn't ANY hope. In some areas, whale populations have started to rebound, albeit slowly. Progress is painstakingly slow. The more we learn about these animals--both during their lives and their impact on the ecosystem after death--then the more we can protect our planet against the terrors of climate change.
There's a lot of ocean out there that we still haven't explored. Perhaps the more we discover, the more we'll learn about these whale falls (and with them, the true impact these animals have on every inch of the ocean). Only time will tell, and I can't wait to see what we find.