In the Deep, Dark Sea, Corals Create Their Own Sunshine

Corals that live up to hundreds of feet below the ocean’s surface have worked out a special arrangement with algae that’s mutually beneficial for the two.
Oceans

Earning their stripes

Corey Filiaggi is describing the busy and collegial environment at the Berman Zebrafish Laboratory, where she’s spent the past three years working towards a master’s degree in Pathology. And it’s true that, only hours after a midnight return from the North Atlantic Zebrafish Research Symposium in Maine, the motley mix of undergraduate and graduate students and lab technicians milling about give off the vibe of a very science-focused village.

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How the South Australians who dumped a nuclear dump may soon have another fight on their hands

The rejection of a plan to import vast amounts of high-level nuclear waste from around the world for profit was a significant result for campaigners but that threat is still far from over, writes JIM GREEN
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The Ecologist

Like a slice of pizza, a curvature could give fish fins their strength

Pizza enthusiasts know well that a simple u-shaped curvature at the crust can keep a thin slice from drooping over when lifted from a plate. A team of engineers from Brown University has shown that fish may take advantage of roughly the same dynamics to stiffen their fins for swimming.

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Video Solves Mystery of How Narwhals Use Their Tusks

Ocean Leadership ~

A new study has shown narwhals , who live in the Arctic, can see with sound. (Credit: Dr. Kristin Laidre/NOAA)

(Click to enlarge) (Credit: Dr. Kristin Laidre/NOAA)

The unicorn of the sea just got a little less mysterious. Until now, how narwhals used their long tusks had been subject to much speculation by scientists. Behavior captured for the first time on camera shows narwhals using the long tusks protruding from their heads to stun Arctic cod by hitting them, using jagged, quick movements. This behavior immobilizes the fish, making them easier to prey upon.

(From National Geographic / by Sarah Gibbens) — The footage was shot by two drones in Tremblay Sound, Nunavat, in Canada’s far Northeastern regions by Adam Ravetch for the World Wildlife Fund Canada and researchers from Fisheries and Oceans Canada.

Brandon Laforest, a senior specialist of Arctic species and ecosystems with WWF-Canada, explained why narwhals have been such a mysterious species.

“They don’t jump like other whales. They are also notoriously skittish,” said Laforest. “This is an entirely new observation of how the tusk is used.”

Laforest, working with officials from the Canadian government, spent time camped in the narwhal’s winter habitat. Because of the remote regions in which narwhals live, visual confirmation of their behavior has been difficult to ascertain.

Marianne Marcoux, a research scientist for Fisheries and Oceans Canada, noted that drones have been an innovative tool for studying these elusive animals.

“Drones are very exciting, we can see things we couldn’t see before,” said Marcoux. Previous aerial observations were conducted by small planes that often provided an incomplete view or frightened the animals.

Three quarters of the world’s population can be found in neighboring Lancaster Sound, which is being considered by the Canadian government for a protected area.

While the footage confirms one theory of how narwhals use their tusks, they may be used for other purposes as well, such as for ice picks, weapons, sexual selection, or as a tool for echolocation. Laforest, however, thinks they may be especially important as sensory organs. Their tusks are covered in thousands of nerve endings and pores that help narwhals sense the environment around them.

“They can feel their surroundings similar to how a human’s broken tooth would have feeling,” said Marcoux.

The tusk is a left canine tooth protruding from the heads of males and can grow as long as nine feet. The right canine stays embedded, and no other teeth protrude from the inside of their mouths; narwhals instead use suction to swallow their prey whole.

The new footage is also significant for conservation efforts because it shows that narwhals feed in the waters in their summer waters. Scientists previously believed they fed exclusively in their winter waters around the southern portion of Baffin Island. Identifying the key regions that narwhals depend on for feeding and calving can help conservationists better preserve their environment and migratory routes.

Read the full story here: http://news.nationalgeographic.com/2017/05/drone-footage-narwhal-tusk-mystery/

 

The post Video Solves Mystery of How Narwhals Use Their Tusks appeared on Consortium for Ocean Leadership.


Consortium for Ocean Leadership

Recordings Reveal That Baby Humpback Whales ‘Whisper’ To Their Mothers

Ocean Leadership ~

A humpback whale and its calf in NOAA's Hawaiian Islands Humpback Whale National Marine Sanctuary. (Credit: NOAA)

(Click to enlarge) A humpback whale and its calf in NOAA’s Hawaiian Islands Humpback Whale National Marine Sanctuary. (Credit: NOAA)

Baby humpback whales seem to whisper to their mothers, according to scientists who have captured the infant whales’ quiet grunts and squeaks.

(From NPR / By Nell Greenfieldboyce) — The recordings, described in the journal Functional Ecology, are the first ever made with devices attached directly to the calves.

“When they’re born, these whales are around 5 meters long,” says Simone Videsen at Aarhus University in Denmark, who notes that this is “pretty big considering it’s a baby.”

Calves must travel with their mothers for thousands of miles during an annual migration to the food-rich waters of the Antarctic. Exactly what happens during that period is a mystery.

“These early life stages of wild whales are so elusive because they’re an aquatic animal,” Videsen explains. “We can’t follow them around all the time to see what they’re doing.”

However, she and some colleagues recently were able to track eight baby whales, using special sound and movement recorders. These recorders had suction cups that let the researchers just stick them onto the babies’ skin. “It can stay there for about a day and then it falls off,” Videsen says.

The researchers weren’t sure exactly what they’d hear when they retrieved the devices and played the audio. It turns out that the babbling of baby whales is very different than the haunting, eerie songs sung by adult male humpbacks.

Read the full story here: http://www.npr.org/sections/thetwo-way/2017/04/26/525609671/recordings-reveal-baby-humpback-whales-whisper-to-their-mothers

The post Recordings Reveal That Baby Humpback Whales ‘Whisper’ To Their Mothers appeared on Consortium for Ocean Leadership.


Consortium for Ocean Leadership

A Genetic Oddity May Give Octopuses And Squids Their Smarts

Ocean Leadership ~

(Click to enlarge) Cirrate octopod, found at around 800m in the Gulf of Maine. View inside mantle. Stauroteuthis syrtensis is one of the few bioluminescent octopuses. Photophores in its mouth are believed to fool prey by directing them towards the mouth. It is relatively common off the continental slope of the eastern USA, although it occurs across the North Atlantic. This specimen was photographed during a 2004-2005 expedition to the Mid-Atlantic Ridge. ( Photo Credit: David Shale)

Coleoid cephalopods, a group encompassing octopuses, squid and cuttlefish, are the most intelligent invertebrates: Octopuses can open jars, squid communicate with their own Morse code and cuttlefish start learning to identify prey when they’re just embryos.

(From The New York Times / by Steph Yin) — In fact, coleoids are the only “animal lineage that has really achieved behavioral sophistication” other than vertebrates, said Joshua Rosenthal, a senior scientist at the Marine Biological Laboratory in Woods Hole, Mass. This sophistication could be related to a quirk in how their genes work, according to new research from Dr. Rosenthal and Eli Eisenberg, a biophysicist at Tel Aviv University.

In the journal Cell on Thursday, the scientists reported that octopuses, squid and cuttlefish make extensive use of RNA editing, a genetic process thought to have little functional significance in most other animals, to diversify proteins in their nervous system. And natural selection seems to have favored RNA editing in coleoids, even though it potentially slows the DNA-based evolution that typically helps organisms acquire beneficial adaptations over time.

Conventional wisdom says that RNA acts as a messenger, passing instructions from DNA to protein builders in a cell. But sometimes, enzymes swap out some letters — the ACGU you might have learned about in school — in the RNA’s code for others. When that happens, modified RNA can create proteins that weren’t originally encoded in the DNA, allowing an organism to add new riffs to its base genetic blueprint.

This RNA editing seemed to be happening more in coleoids, so Dr. Eisenberg, Dr. Rosenthal and Noa Liscovitch-Brauer, a postdoctoral scholar at Tel Aviv University, set out to quantify it by looking for disagreements in the DNA and RNA sequences of two octopus, one squid and one cuttlefish species.

They found that coleoids have tens of thousands of so-called recoding sites, where RNA editing results in a protein different from what was initially encoded by DNA. When they applied the same methods to two less sophisticated mollusks — a nautilus and a sea slug — they found that RNA editing levels were orders of magnitude lower.

Next, the researchers compared RNA recoding sites between the octopuses, squid and cuttlefish species and found that they shared tens of thousands of these sites to varying degrees. By comparison, humans and mice share only about 40 recoding sites, even though they are hundreds of millions of years closer in evolution than octopuses and squids.

“Evolutionarily, that’s a big deal,” said Jin Billy Li, an assistant professor of genetics at Stanford, who was not involved in this study. The findings suggest that the editing sites are very important, he added.

Read the full article here: https://www.nytimes.com/2017/04/06/science/octopus-squid-intelligence-rna-editing.html?_r=0

The post A Genetic Oddity May Give Octopuses And Squids Their Smarts appeared on Consortium for Ocean Leadership.


Consortium for Ocean Leadership

Indonesia: Villagers resist eviction for 50 sq.km airport city on their land

Ten villages and surrounding farmland have already been wiped from the map for a 50 sq.km airport and surrounding ‘aeropolis’ or airport city in West Java, Indonesia, writes Rose Bridger. And while investors are offered an ‘attractive incentives plan’, villagers are subject to fierce state repression and brutality. Now only a single village remains standing, but residents continue to resist eviction and demand an end to the project.
Environment news & analysis, climate change reports –
The Ecologist

Manatees Just Lost Their Status as Endangered Species

Manatees have just been downlisted from endangered to threatened; and while some are celebrating their recovery, many advocates are fearing that the move puts their future survival in jeopardy.

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Species’ traits influenced their response to recent climate change

Modelling of mammal and bird responses to recent climatic changes—based on a systematic review of the literature—suggests that large numbers of threatened species have already been affected by climate change in at least part of their range.

Nature Climate Change doi: 10.1038/nclimate3223


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