Argus – California Sea Lion
Rescued: October 4, 2017
Released: October 25, 2017
Diagnosis: Leptospirosis

California sea lion Argus was rescued just a few miles from The Marine Mammal Center near a busy marina. Our veterinary experts determined that he was suffering from leptospirosis, a bacterial infection of the kidneys. Argus was one of several dozen California sea lions we treated for leptospirosis in 2017. Treatment for the potentially lethal infection includes antibiotics, fluids and other supportive care, such as gastro-protectants for stomach and intestinal ulcers. Once Argus had recovered fully from the disease, he was released back to the wild just steps from our hospital.

Scientists use drone to sample whale breath and snot To study the microbiome of humpback whales

Scientists flew a small drone over the blowhole of a few humpback whales in the US and Canada to collect the microbes living inside their breath. Sampling the community of microbes and bacteria living inside whales, called the microbiome, can help us better understand what makes a healthy whale, and what happens when a whale gets sick.

In the new research, published this week in the journal mSystems, scientists describe 25 species of microbes found in each humpback’s breath they sampled. Though they don’t know how exactly these organisms affect the health of the whales yet, many of the same microbes are often found in other marine mammals, suggesting they play a role in keeping the animals healthy. The study is also the latest example of how drones can help scientists in their quest to conserve species: in Hawaii, botanists are also using drones to hunt down rare plants in hard-to-reach places like cliffs.

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Just like humans, animals have a microcosm of organisms inhabiting their bodies — which help keep them healthy. While we’re just starting to explore the human microbiome and its functions, very little is known about the microbiome of whales, especially inside their breathing organs, where a lot of infections occur. So researchers decided to sample the spray of water and snot coming out of the hole atop the whale heads, which the animals use to breathe at the surface.

Usually, whale breath is collected by approaching the animals — which can be up to 60 feet long, in the case of humpbacks — with a small boat, and then holding 23-foot pole with a collection plate above the blowhole. That’s obviously time-consuming and dangerous — for people and whales. In search for a better method, scientists used a remote-controlled hexacopter equipped with a petri dish. They then flew it a few feet over the blowhole of 26 healthy humpback whales off the coast of Cape Cod in the Atlantic Ocean and Vancouver Island in the Pacific.


The researchers found 25 species of microbes in the breath of all whales, including 20 that were previously found in other marine mammals. That suggests that those organisms are connected to the creatures’ respiratory health, according to the study, although it’s not exactly clear how. But understanding what makes the microbiome of a healthy whale can help us monitor their health, identify dangerous pathogens in the future, and possibly understand how pollutants in the water can affect whales.

That’s key for their conservation. A number of large whales are listed as endangered or critically endangered, including some humpback whale populations off the coast of northwest Africa and Central America.



The secret of dolphins’ speed is not skin-deep, study shows


Does dolphin skin have secret powers that allow the flippered mammals to outrace boats? Scientists looking to answer this question have found that dolphins achieve impressive swimming speeds based on muscle power alone.

The findings, published in the Journal of Experimental Biology, solve a longtime mystery on the nature of dolphin propulsion.

Researchers have wondered how dolphins manage to swim so fast at least since the 1930s, when British zoologist James Gray marveled at reports of one dolphin’s apparent speed as it outraced a boat. Gray calculated that the dolphins simply didn’t have the muscle power to swim that fast; they must somehow use a trick of fluid mechanics to overcome the drag that would hold them back. This observation became known as Gray’s paradox.

The answer to Gray’s paradox was thought to lie in dolphins’ smooth skin. Could it manipulate water flow to reduce drag and improve speed? (It’s a reasonable idea – after all, speedy mako sharks have skin covered in tiny toothlike scales that help them make hairpin turns by controlling flow separation.)

The lure of such potential drag reduction spawned a host of research, said lead author Frank Fish, a biomechanist at West Chester University in Pennsylvania. This was particularly true in the 1960s during the Cold War, when both Russia and the U.S. coveted the dolphin’s supposed secrets.

“Cold war paranoia afflicted both Pentagon and Kremlin in the form of wildly exaggerated estimates of the speeds of each other’s submarines,” Duke University biomechanist Steven Vogel wrote in the book “Comparative Biomechanics: Life’s Physical World.”

Researchers tried to pick apart the secrets of dolphin skin in a number of ways, wrapping rubbery artificial skin around test torpedoes and even dragging naked young women (or “nekkid leddies,” as referenced here) through the water to see how their skin responded to the drag. (Women have more fatty tissue under their skin than men do, which gives their skin more “dolphin-like” properties, Fish said.)

Nowadays, to watch how animals affect the flows around them as they move through water, researchers often fill a water tank with 10-micron-wide glass beads and shoot a laser sheet through the water to illuminate the beads and watch how the animals’ movement affects the beads and thus disturbs the flow.

You can do this with jellyfish, not so much with dolphins, Fish said – there are concerns about what would happen if the laser hit them in the eye or if they ingested the beads.

“It’s one thing to work with a fish, it’s another thing to work with a dolphin – we tend to protect them,” Fish said. “Dolphins are very pampered animals, when we keep them.”

Luckily, Fish said, engineer Timothy Wei of the University of Nebraska-Lincoln had been working with other “pampered animals” – Olympic swimmers – and had come up with an ingenious and low-cost solution to track them as they swam.

Instead of using glass beads, Wei used air bubbles. Here’s how: They got a garden soaker hose that’s typically used to water lawns and pumped air through it from an oxygen tank. The tiny bubbles that came out of the hose’s pores created a sheet of bubbles that, when illuminated by sunlight, could act just like the reflective glass beads in the laser sheet.

The scientists had Primo and Puka, two retired Navy dolphins, swim along the length of the bubble wall. After watching the patterns created in the bubbles, the scientists realized that the bottlenose dolphins were producing an incredible amount of power – enough to overcome the enormous drag they were experiencing.

So the answer to Gray’s paradox? There was no paradox, Fish concluded.

“First off, we can stop looking for a magic mechanism to reduce drag,” Fish said. “There may be ways to reduce drag, but the dolphin [skin] isn’t going to show us those.”

In any case, he added, “it basically starts to tell us things about how well designed these aquatic athletes are.”

It could mean that flippered robots could theoretically be an alternative to the propeller-driven kind, said Fish, who said he’s currently working on creating a manta ray robot.

In the meantime, the bubble method of tracking animals’ flow patterns might be useful in testing larger animals in the open ocean – it’s certainly more portable than the laser-and-beads method, Fish said.