{"id":28430,"date":"2014-10-15T08:07:36","date_gmt":"2014-10-15T18:07:36","guid":{"rendered":"http:\/\/www.hawaii.edu\/news\/?p=28430"},"modified":"2021-10-25T10:28:54","modified_gmt":"2021-10-25T20:28:54","slug":"importance-of-jellyfish-falls-to-deep-sea-ecosystem-revealed","status":"publish","type":"post","link":"https:\/\/www.hawaii.edu\/news\/2014\/10\/15\/importance-of-jellyfish-falls-to-deep-sea-ecosystem-revealed\/","title":{"rendered":"Importance of jellyfish falls to deep-sea ecosystem revealed"},"content":{"rendered":"Reading time: <\/span> 3<\/span> minutes<\/span><\/span>
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Hagfish and crustacean amphipods scavenging jellyfish baits in the deep sea. (credit: A. Sweetman, C. Smith, D. Jones)<\/figcaption><\/figure>\n

Researchers from University of Â鶹´«Ã½<\/span><\/a>, Norway, and the UK<\/abbr> 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.<\/p>\n

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.<\/p>\n

“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,“ said lead author Andrew K. Sweetman<\/a>. “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.” Sweetman is a chief senior scientist and research coordinator for deep-sea ecosystem research at the International Research Institute of Stavanger<\/a> in Norway.<\/p>\n

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