Hordes of mysterious sea creatures have been invading the west coast of the United States, from California to Alaska. No, they aren’t some scary shark species or giant squid. The strange aquatic animals are actually pyrosomes, which are more commonly known as “sea pickles” to the general public.
A sea pickle is not an individual organism. Each one is made up of colonies of thousands of multicellular organisms, called zooids. These zooids come together to form a bumpy, tubular creature that resembles a gelatinous, almost transparent, pickle. Though many are only a few inches long, they can reach up to sixty feet in length under the right conditions.
Not much is known about the sea pickle, but scientists believe they feed by filtering phytoplankton, which is microscopic algae that floats in the ocean. The most interesting thing about them is that they are bioluminescent, so you can see them glowing at night in the Pacific Ocean.
Sea pickles are not dangerous to people, unlike the similarly squishy jellyfish, to which they are not related. They have, however, put a significant dent in the fishing industry from Oregon to Alaska. They have become so numerous that a recent five-minute trawl by researchers picked up nearly 60,000 of the rubbery creatures. They cause trouble for fishermen when they clog up fishing gear. The problem has gotten so bad that many commercial fishermen have had to find new areas to fish for species like salmon and halibut.
The animals are not native to the waters off the United States. Their true habitat is in tropical waters further south, near places like Australia. But climate change has caused their home waters to become too warm to support them, so they have drifted north. The same warming phenomenon has led to problems for other sea life, as well, such as an increase in strandings of sea lions.
There is some concern that these out-of-place animals could harm the environment of the United States’ Pacific Coast. It is possible that their unusually large numbers could consume too much of the phytoplankton in the area, which could kill off native species, including krill, which also eat the tiny organisms. This could in turn affect whales and seabirds who depend on the krill for their food.
Scientists are also concerned that the sea cucumbers could experience a massive die-off, since they are now in waters not meant to support them. Such a mass of decaying matter could deplete the oxygen in the water, creating a dead zone. There is already such a dead zone in the Gulf of Mexico that was caused by large numbers of algae and plankton dying at the same time.
For the time being, researchers are doing all they can to learn more about the species, as their prior rarity have made them difficult to study. It is hoped that they can figure out why they have migrated so far north and that they can determine how to mitigate any damage they may cause to ecosystem of America’s Pacific coast.