This week, researchers from University of Hawai’i, Norway, and the UK have shown with innovative experiments that a rise in jellyfish blooms near the ocean’s surface may lead to jellyfish falls that are rapidly consumed by voracious deep-sea scavengers. Previous anecdotal studies suggested that deep-sea animals might avoid dead jellyfish, causing dead jellyfish from blooms to accumulate and undergo slow degradation by microbes, depleting oxygen at the seafloor and depriving fish and invertebrate scavengers, including commercially exploited species, of food.
Globally there are huge numbers of jellyfish in the oceans. In some parts of the ocean, jellyfish “blooms” are increasing apparently due to nutrient enrichment and climate change caused by human activities. In recent years, studies have suggested that when jellyfish blooms die-off, massive quantities of jellyfish sink out of surface waters and can deposit as “jelly-lakes” at the seafloor, choking seafloor habitats of oxygen and reducing biodiversity. This latest research shows that the accumulation of dead jellyfish lakes may be unusual, with jellyfish carcasses normally being rapidly consumed by a host of typical deep-sea scavengers such as hagfish and crabs.
“We just had a hunch that dead jellyfish were important to deep-sea ecosystems in some way, even though they are made up largely of water. We therefore decided to film what the fate of jellyfish carcasses were at the seafloor so we deployed deep-sea lander systems with jellyfish bait. When we later retrieved the landers and found no jellyfish attached to the bait plates we were pleasantly surprised. However, our surprise jumped to another level when we looked at the camera images and saw just how fast the jellyfish baits were consumed and the shear number of scavengers that were consuming the baits. It just blew our minds.” lead author Andrew K. Sweetman said. Sweetman is a chief senior scientist and research coordinator for deep-sea ecosystem research at the International Research Institute of Stavanger in Norway.
Published October 15 in the prestigious journal Proceedings of the Royal Society: Biological Sciences, the research looked at the response by scavengers to jellyfish and fish baits in the deep-sea along the Norwegian margin. The researchers found that jellyfish and fish baits were consumed equally fast and attracted similar densities of a diversity of scavengers.
“The speed of the jellyfish scavenging was totally unexpected because earlier, previous observations seemed to suggest that jellyfish carcasses would just rot very slowly at the seafloor. It was also really interesting that the hagfish targeted the most energy-rich parts of the jellyfish, burrowing into the jellyfish carcasses to eat the gonads!” said Craig R. Smith, co-author, designer of the deep-see camera-lander systems used in the study, and a Professor of Oceanography and Pew Fellow in Marine Conservation at the University of Hawai’i at Mānoa, USA.
The study further revealed that the role of jellyfish material could be seriously underestimated in global carbon budgets in the ocean, because jellyfish were removed so quickly that they fail to accumulate at the seafloor, causing scientist to overlook their role in deep-sea food webs.
“Our work shows that previous assessments of the ocean carbon cycle may have missed an important component. Until we saw these photos we thought that the massive amount of jellyfish material was deposited on the seafloor and was essentially taken out of the system – removing carbon rapidly. Our results show that much of this carbon could, in fact, make it into deep-sea food webs, fueling these systems. This is especially important when other food sources to deep-sea ecosystems may be decreasing as our oceans warm” said co-author Daniel Jones, a scientist at the National Oceanography Center in Southampton UK.
Ultimately, this new research reveals that jellyfish blooms could provide far-reaching, potentially important, food supplements to normal deep-sea food webs, rather than having purely negative impacts on fisheries and marine ecosystem function.
Here are some awesome facts about Jellyfish
1. Some jellyfish can glow in the dark
Many jellyfish have bioluminescent organs, which emit light. This light may help them in a number of different ways, like attracting prey or distracting predators.
2. Jellyfish can clone themselves
If a jellyfish is cut in two, the pieces of the jellyfish can regenerate and create two new organisms. Similarly, if a jellyfish is injured, it may clone itself and potentially produce hundreds of offspring.
3. Some jellyfish are immortal
There are two phases to jelly life: the stationary polyp stage and the mobile medusa phase. It’s the medusa phase that we’re usually referring to when we talk about jellyfish. Typically, jellies start as polyps and develop into medusas, but the Turritopsis nutricula has earned it the nickname “the immortal jellyfish” for having the ability to travel backward to the polyp stage in times of stress.
4. Jellyfish can teach us about efficient underwater propulsion
The movements of bell-shaped jellyfish have provided researchers with a new understanding of propulsion. The flexibility of their umbrella-like bodies allow them to pulse upwards and downwards without expending much energy. Researchers have created biomimetic robots with flexible bells, which may one day lead to better undersea vehicles.
5. Not all jellies have tentacles
The scyphomedusa deepstaria, shown in the video below, doesn’t need tentacles to trap its prey.
6. There’s a giant jellyfish called the pink meanie
The scientific name for this jelly is Drymonema larsoni, but its aggressive sting and distinctive color have earned it the nickname “pink meanie.”
7. Jellyfish don’t have brains
Instead, jellyfish have nerve nets which sense changes in the environment and coordinate the animal’s responses.
8. Jellyfish movements inspired a new way to fly
It’s probably not that surprising that jellyfish have served as inspiration for swimming robots. However, it’s more unusual to see a sea creature inspire a flying machine, but that’s just what happened at New York University.
9. Jellyfish powder has been used to make salted caramel
Turtles eat jellyfish, and larger jellies may eat smaller ones, but are jellyfish fit for human consumption? A group of high school students in Japan came up with a salted caramel recipe that uses powered jellyfish. It’s not vegan for sure, but it is one way to deal with an invasive jellyfish bloom.
10. Glowing jellyfish goo could power medical devices
Another jellyfish-derived product takes advantage of the jellies’ fluorescent protein, and could be used to power medical devices in the future.
11. Jellyfish are surprisingly good at shutting down nuclear reactors
In the past decade, jellyfish blooms have been responsible for shutting down several nuclear reactors, which often rely on ocean water intakes. The jellyfish swarms can clog the intake pipes, forcing facilities to stop operating temporarily.
12. Jellyfish will eat peanut butter
Two Aquarists in Dallas, Texas created a saltwater/peanut butter mix and fed it to moon jellies. Apparently, the jellies found this mix to be an acceptable source of protein. “We would love to claim we conducted this trial with noble purpose, but the truth is that we just wanted to make peanut butter and jellyfish simply to see if it could be done,” the researchers write.
13. Some jellyfish look like trash bags.
They’re known as Deepstaria enigmatica, and are usually found in the Arctic seas.
And to finish you off, here is a “Soothing Meditation with the Portuguese Man-of-War
University of Hawaii: The University of Hawaiʻi at Mānoa is a public, co-educational university and is the flagship campus of the greater University of Hawaiʻi system. The school is located in Mānoa, an urban neighborhood community of Honolulu CDP, City and County of Honolulu, Hawaiʻi, United States, approximately three miles east and inland from downtown Honolulu and one mile (1.6 km) from Ala Moana and Waikīkī. The campus occupies the eastern half of the mouth of the greater Mānoa Valley. It is accredited by the Western Association of Schools and Colleges and is governed by the Hawaiʻi State Legislature and a semi-autonomous Board of Regents, which in turn hires a president to be administrator. The university campus houses the main offices of the UH System. The University of Hawaii at Mānoa was founded in 1907 as a land grant college of agriculture and mechanical arts. In 1912 it was renamed the College of Hawaii and moved to its present location. William Kwai Fong Yap petitioned the territorial legislature six years later for university status which led to another renaming to the University of Hawai’i in 1920. This is also the founding year of the College of Arts and Sciences.