Whale falls can be found throughout the ocean. This one was spotted in Channel Islands National Marine Sanctuary, off the coast of Southern California!
When I was a child, my father would take me trout fishing, and I spent hours marveling from the riverbank at the trouts’ ability to, seemingly effortlessly, hold their position in the fast-moving water. As it turns out, those trout really were swimming effortlessly, in a manner demonstrated above. The fish you see here swimming behind the obstacle is dead. There’s nothing powering it, except the energy its flexible body can extract from the flow around it.
The obstacle sheds a wake of alternating vortices into the flow, and when the fish is properly positioned in that wake, the vortices themselves flex the fish’s body such that its head and its tail point in different directions. Under just the right conditions, there’s actually a resonance between the vortices and the fish’s body that generates enough thrust to overcome the fish’s drag. This means the fish can actually swim upstream without expending any energy of its own! The researchers came across this entirely by accident, and one of the questions that remains is how the trout is able to sense its surroundings well enough to intentionally take advantage of the effect. (Image and research credit: D. Beal et al.; via PhysicsBuzz; submitted by Kam-Yung Soh)
PRIMITIVE COELACANTH ARE EATING PLASTIC DEBRIS IN INDONESIA
A coelacanth was found dead off the coast of Indonesia with a plastic wrap from Lay’s potato chips inside its guts. The image was originally taken in 2016 by an Indonesian fisherman, but recently was shared by Blue Planet Society on Twitter. This is the first report of marine debris ingestion by coelacanth, and despite this coelacanth was found dead, there is no certainty if the plastic wrap was involved in the decease.
The Indonesian coelacanth (Latimeria menadoensis), one of two living species of coelacanth, is listed as vulnerable by the IUCN Red List. There are around 10,000 mature individuals remain in the wild. Although they have no value as food, they are extremely susceptible to bycatch by deep sea fishermen.
This relationshiop between marine fauna and debris is not a surprise, since China, Indonesia, the Philippines and Vietnam,are spewing out as much as 60 percent of the plastic waste that enters the world’s seas.
Coelacanths
were once believed to have gone extinct and were known for a long time only through fossils. In 1938, a living specimen was unexpectedly discovered in deep waters off South Africa. Coelacanth are opportunistic predator, meaning it will eat anything that crosses it’s path while it hunts for food, living in deep waters at 150-200 m depth.
