Lady Darwin

Why You Should Care That Sea Cucumbers Are Going Extinct

by Jason G. Goldman

Sea cucumbers are in trouble. Everyone knows about the problems that elephants and rhinos face due to poaching, that dolphins face due to drive hunts, and that sharks face when overzealous governments try to convince their constituents that they’re helping them avoid shark attacks. Sea cucumbers may not be as charismatic as their megafaunal counterparts, but they actually provide an important service for reef ecosystems.

They help to keep the sand in reef lagoons and seagrass beds fresh by turning them over, and by feeding on the dead organic matter that’s mixed in with the sand, the nutrients they excrete can re-enter the biological web by algae and coral. Without the sea cucumbers, that sort of nutrient recycling could not occur. It’s also thought that sea cucumbers help to protect reefs from damage due to ocean acidification. Feeding on reef sand appears to increase the alkalinity of the surrounding seawater.

The problem, according to a study conducted by Steven Purcell and Beth Polidoro, is that sea cucumbers are considered a luxury snack. As they explain at The Conversation, dried-out versions of the tropical species retail between $10 and $600 per kilogram in Hong Kong and on mainland China. There’s actually one species that is sold for $3000 per kilo, dried. Sea cucumbers are thought of as “culinary delicacies,” and often adorn the buffets of festival meals and are served at formal dinners…

It was shocking to hear/see how much comes into just San Francisco during a short week-long time frame… literally tons of sea cucumbers come in to this port yearly (amounting to many many many many thousands of individuals).

Plus, they’re incredibly difficult to ID to species level once dried, and few to none are currently protected despite little knowledge about how the wild populations are doing.

"Oh, what a cute little mouse!"

"It’s not a mouse! It’s a marsupial called an antechinus."

"Sorry, evolution, my mistake. Still cute, though."

"Isn’t he? And he’s excited, because he’s almost eleven months old, and that means he finally gets to start mating."

"Aw, that’s nice."

"He’s going to run around getting it on with as many females as he can for the next two or three weeks."

"That’s… nice."

"And he’ll have sex with each of them for up to 14 hours at a stretch."

"That’s… um…"

"And he’ll get so exhausted from all the frantic mating that his fur starts falling off, and he contracts gangrene."

"What? Jesus. Then does he take a break, at least?"

"Nah, not really. He basically keeps doing it until he gets so sick and stressed out that he dies. ‘Suicidal reproduction,’ I’m calling it.”

"Are you serious? He’s going to mate himself to death?”

"Yeah, but he doesn’t know it yet. Happy coming-of-age, antechinus!"

Marvel has announced the Ultimate Mentor Adventure, part mentor program, part contest, that gives American girls in grades 9-12 the resources to find and interview professional women in science, technology, engineering, and math, and then rewards them for doing it.

Bioluminescence is the ability of a living thing to produce light. Everyone knows fireflies, but there are so much more organisms that glow.

Report Reveals Cause of Massive Madagascar Whale Stranding (Op-Ed)

Michael Jasny is director of the NRDC Marine Mammal Project. This Op-Ed is adapted from one on the NRDC blog Switchboard. Jasnycontributed this article to LiveScience’s Expert Voices: Op-Ed & Insights.

Sometimes good science takes time. This week, more than five years after the fact, a report was released about a mysterious mass stranding of whales that made international news in its day, but has since been all but forgotten.

Few will be surprised to learn that the cause was manmade ocean noise, which has now been implicated in a succession of mass whale deaths. And yet the findings were completely unexpected — and raise yet more questions about the sufficiency of existing law to address this growing international problem.

On May 30, 2008, a pod of some 100 to 200 melon-headed whales turned up in Loza Lagoon, a large mangrove estuary on the northwest end of Madagascar. The lagoon was, needless to say, an inappropriate place for pelagic whales that tend to spend their lives in deep water. Despite intensive rescue efforts by both local authorities and experts from around the world, including my colleagues at the International Fund for Animal Welfare and Wildlife Conservation Society, the vast majority of the whales in Loza proceeded to suffer, starve and die.

The whole episode bore an uncanny resemblance to a mass stranding of the same species in Hawaii, during a major U.S. Navy exercise in 2004. In that case, an intrepid group of locals managed to lead the whales out of the lagoon using traditional methods — strands of woven vines gently pulled along the water’s surface — but Madagascar was the darker flipside of that event. In Hawaii only a single whale, a calf, is known to have died. In Madagascar, it was a true catastrophe.

But what was the cause? At the time, attention immediately turned to Exxon, which was running exploration activities in the area. The high-powered airguns that companies use to find offshore reservoirs of oil and gas have the power to disrupt marine life on a massive scale, and have raised enormous concern among scientists and conservationists the world over. Yet Exxon hadn’t deployed airguns off Madagascar. Nor was it using any of the other intense human sources of sound that biologists have identified as an environmental threat.

What the report demonstrates is that our understanding of the threat from underwater noise is too narrow. As it turns out, the “plausible and likely” cause of the Madagascar strandings was a seemingly innocuous acoustic device called a multibeam echosounder, which uses fans of sound to produce high-resolution maps of the sea floor.

No one thought to worry about echosounders before now. For years, regulators have focused on industrial and military sounds of lower frequencies, on the assumption that higher-frequency sounds are more quickly absorbed by seawater and do not pose the large-scale threat of an industrial airgun or naval sonar system. And echosounders, which are widely used by fishermen and oceanographers as well as by industry, typically use frequencies so high as to be completely undetectable to any marine mammal.

Green Sea Slug Is Part Animal, Part Plant

It’s easy being green for a sea slug that has stolen enough genes to become the first animal shown to make chlorophyll like a plant.

Shaped like a leaf itself, the slug Elysia chlorotica already has a reputation for kidnapping the photosynthesizing organelles and some genes from algae. Now it turns out that the slug has acquired enough stolen goods to make an entire plant chemical-making pathway work inside an animal body, says Sidney K. Pierce of the University of South Florida in Tampa.

The slugs can manufacture the most common form of chlorophyll, the green pigment in plants that captures energy from sunlight, Pierce reported January 7 at the annual meeting of the Society for Integrative and Comparative Biology. Pierce used a radioactive tracer to show that the slugs were making the pigment, called chlorophyll a, themselves and not simply relying on chlorophyll reserves stolen from the algae the slugs dine on.

“This could be a fusion of a plant and an animal — that’s just cool,” said invertebrate zoologist John Zardus of The Citadel in Charleston, S.C.

Microbes swap genes readily, but Zardus said he couldn’t think of another natural example of genes flowing between multicellular kingdoms.

Pierce emphasized that this green slug goes far beyond animals such as corals that host live-in microbes that share the bounties of their photosynthesis. Most of those hosts tuck in the partner cells whole in crevices or pockets among host cells. Pierce’s slug, however, takes just parts of cells, the little green photosynthetic organelles called chloroplasts, from the algae it eats. The slug’s highly branched gut network engulfs these stolen bits and holds them inside slug cells.

Some related slugs also engulf chloroplasts but E. chlorotica alone preserves the organelles in working order for a whole slug lifetime of nearly a year. The slug readily sucks the innards out of algal filaments whenever they’re available, but in good light, multiple meals aren’t essential. Scientists have shown that once a young slug has slurped its first chloroplast meal from one of its few favored species of Vaucheria algae, the slug does not have to eat again for the rest of its life. All it has to do is sunbathe.

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The Twisted Trees of Slope Point, New Zealand

Slope Point is at the southernmost point of the South Island of New Zealand. The air streams loop the ocean, unobstructed for 2000 miles, until they reach Slope Point causing incredibly strong winds. In fact, the winds are so strong and persistent here that they perpetually warp and twist the trees into these crooked, wind-swept shapes. 

Slope Point is generally uninhabited, except for the herds of sheep that graze the land. There are no roads leading here, however backpackers regularly make the short 20-minute walk to see the fascinating tree formations that only Mother Nature could create. However there is no public access during the lambing season from September to November.

Kivalina: The Alaskan village set to disappear under water in a decade

Almost no one in America has heard of the Alaskan village of Kivalina. It clings to a narrow spit of sand on the edge of the Bering Sea, far too small to feature on maps of Alaska, never mind the United States.

Which is perhaps just as well, because within a decade Kivalina is likely to be under water. Gone, forever. Remembered - if at all - as the birthplace of America’s first climate change refugees.

Four hundred indigenous Inuit people currently live in Kivalina’s collection of single-storey cabins. Their livelihoods depend on hunting and fishing.

John Skylar (via tofias)

Yes!