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.
Link to video and interview (more information below): http://bit.ly/ZYsSNS
BROLL (45 seconds followed by soundbites):
Video of jellyfish being eaten by ocean scavengers
Craig Smith - Oceanography professor, University of Hawaiʻi at Mānoa (11 seconds)
"And this is real, actually quite important. As the climate warms, as humans change the climate of the earth, and as they put nutrients in the ocean, there's an increase in the abundance of jellyfish."
Smith (14 seconds)
"It may mean that these changes that are occurring in the ocean where jellyfish are becoming more abundant are not as significant, not as bad as we thought they might be. The ocean may be more able to adjust to these changes than we expected."
Smith (13 seconds)
"We've only been able to do these experiments in one location. The scavengers that come are typical of the deep sea but it would be nice to replicate or repeat these experiments in other parts of the ocean to show that the scavenging processes are similar."
Sweetman AK, Smith CR, Dale T, Jones DOB. 2014. Rapid scavenging of jellyfish carcasses reveals the importance of gelatinous material to deep-sea food webs. Proceedings of the Royal Society B 281: 20142210. http://dx.doi.org/10.1098/rspb.2014.2210
The School of Ocean and Earth Science and Technology at the University of Hawaii at Manoa was established by the Board of Regents of the University of Hawai'i in 1988 in recognition of the need to realign and further strengthen the excellent education and research resources available within the University. SOEST brings together four academic departments, three research institutes, several federal cooperative programs, and support facilities of the highest quality in the nation to meet challenges in the ocean, earth and planetary sciences and technologies.
Marcie Grabowski | Eurek Alert!
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
The disappearance of common species
01.02.2018 | Technical University of Munich (TUM)
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).
Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
16.02.2018 | Information Technology
16.02.2018 | Health and Medicine
16.02.2018 | Physics and Astronomy