Sea stars filmed hunting squid and squabbling over eating it

30 May 2017

By Chelsea Whyte

It’s like going back in time. NOAA’s Okeanos Explorer has completed more than two weeks of ocean exploration beginning near Pago Pago, the capital of American Samoa, and ending near Honolulu in Hawaii. Some of the animal behaviour it recorded has previously been documented only in fossils hundreds of millions of years old.

“For all of the places we went, it was the first time we were getting to have eyes down in the deep sea,” says Scott France, a deep-sea biologist at the University of Louisiana at Lafayette who was on the ship.

Those eyes come in the form of remote submersibles that light up the sea floor and transmit live video to the team and the public around the world.

“We saw brittle stars capturing a squid from the water column while it was swimming. I didn’t know that was possible. And then there was a tussle among the brittle stars to see who got to have the squid,” says France.
Living fossils

The team also saw snails attached to crinoids, sometimes called sea lillies for their graceful branches.

“We saw this amazing footage of the snail that seemed to be eating a crinoid. No one had seen this before,” says Del Bohnenstiehl at North Carolina State University in Raleigh, a geologist on the ship. “A scientist from the Smithsonian said he had seen it in the fossil record, but never live.”



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Dissolving Sea Stars Reveal a Damaged Ocean

Lynn Wilson, Kaplan University and SeaTrust Institute | June 06, 2015 01:25am ET

Lynn Wilson, is Academic Department Chair for Public Administration at Kaplan University and founder and CEO of the SeaTrust Institute. A science journalist and academic author, Wilson is also a delegate for the United Nations Framework Convention on Climate Change and other United Nations regimes, a reviewer for the U.S. National Institutes of Health and the IPCC, and an active researcher with projects in Africa and the Pacific Islands. She contributed this article to Live Science's Expert Voices: Op-Ed & Insights.

On a remote Pacific Northwest beach, the intertidal world reveals itself to the air breathers. Mussels and gooseneck barnacles fasten to exposed rocks that shelter the apex predators: ochre sea stars (Pisaster ochraceus). But something is wrong. White spots spread across the stars' disintegrating arms, and instead of regrowing the damaged appendages as sea stars often do, the entire animal rapidly dissolves into a mass of goo. 

First noticed in Washington state in 2013, "sea star wasting disease" reached alarming proportions by July 2014, its cause unknown — even though the disease was first identified in 1979.

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Virus devastating sea stars on Pacific Coast identified

Museum biological collections are the records of life on Earth and as such, they are frequently used to investigate serious environmental issues. When public health officials were concerned about the levels of mercury in fish and birds, for example, scientists studied museum specimens to assess historical changes in mercury contamination. Eggs in museum collections were analyzed to establish the connection between DDT, thinning eggshells, and the decline in bird populations. And now, specimens from the Natural History Museum of Los Angeles County (NHM) have helped explain the mysteriously sudden appearance of a disease that has decimated sea stars on the North American Pacific Coast.

In a paper published Monday, November 17, 2014 in the journal Proceedings of the National Academy of Sciences, Cornell University microbiologist Ian Hewson and colleagues identify the Sea Star Associated Densovirus (SSaDV) virus as the microbe responsible for Sea Star Wasting Disease (SSWD). NHM Curator of Echinoderms Gordon Hendler and Collections Manager Cathy Groves, along with scientists from universities and aquariums along the coast (including NHM neighbor, the California Science Center), collaborated in the study.

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Young sea stars suffer more from ocean acidification than adults

Date:

September 26, 2014

Source:

Helmholtz Centre for Ocean Research Kiel (GEOMAR)

Summary:

Young sea stars from the Baltic Sea suffer more from the effects of ocean acidification than adults. In a laboratory experiment, scientists showed that younger animals already eat less and grow more slowly at only slightly elevated carbon dioxide concentrations.

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Why Are Sea Stars Dying from New Jersey to Maine? Divers Asked to Report Large Groupings of Starfish

July 23, 2013 — When University of Rhode Island graduate student Caitlin DelSesto collected starfish in Narragansett Bay for an undergraduate research project in 2011, she was surprised to watch as the animals appeared to melt and die in her tank within a week. After bringing it to the attention of URI Professor Marta Gomez-Chiarri, she learned it was among the first observations of a new disease that is now affecting starfish -- also called sea stars -- from New Jersey to Maine.

Thanks to a grant from the Rhode Island Science and Technology Advisory Council, the URI researchers are collaborating with scientists at Brown University and Roger Williams University to try to identify the cause of the disease.

"There was a big increase in sea star numbers about three or four years ago," said Gomez-Chiarri, "and often when you have a population explosion of any species you end up with a disease outbreak. When there's not enough food for them all it causes stress, and the density of animals leads to increased disease transmission.

"Now that the disease is in the environment, it may be hard to get the population back to normal," she added. "Diseases don't just completely disappear after a massive die-off."

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