Conservation & Science

Pinpointing plastic’s path to the deep sea

Until now, little has been known about how microplastics move in the ocean. A new paper by our colleagues at the Monterey Bay Aquarium Research Institute (MBARI), just published in the journal Science Advances, shows that filter-feeding animals called giant larvaceans collect and consume microplastic particles in the deep sea.

Larvaceans are transparent tunicates that live in the open sea and capture food in sticky mucus filters. Plastic particles accumulate in the cast-off mucus feeding filters and are passed into the animals’ fecal pellets, which sink rapidly through the water, potentially carrying microplastics to the deep seafloor.

Researchers at MBARI documented that tadpole-like giant larvaceans consume microplastic beaads. Photo courtesy MBARI.

The new findings contribute to an emerging picture about the ubiquitous nature of ocean plastic pollution. Over the last decade, scientists have discovered tiny pieces of plastic in all parts of the ocean—including deep-sea mud. One recent study documented microplastic fibers in deep-sea sediments at levels four times greater than an earlier study had found in surface waters. Plastic has also been discovered in the tissues of animals at the base of the ocean food web. Another just-published study found that fish confuse plastic particles with real food items because it smells just like organic matter in the ocean.

Despite their name, giant larvaceans are less than 10 millimeters (4 inches) long, and look somewhat like transparent tadpoles. Their mucus filters—called “houses” because the larvaceans live inside them—can be more than 1 meter (3 feet) across. These filters trap tiny particles of drifting debris, which the larvacean eats. When a larvacean’s house becomes clogged with debris, the animal abandons the structure and it sinks toward the seafloor.

Principal Engineer Kakani Katija studies giant larvaceans during field expeditions in Monterey Bay. Photo courtesy MBARI.

In early 2016, MBARI Principal Engineer Kakani Katija was planning an experiment using the DeepPIV system to figure out how quickly giant larvaceans could filter seawater, and what size particles they could capture in their filters. Other researchers have tried to answer these questions in the laboratory by placing tiny plastic beads into tanks with smaller larvaceans. Because giant larvacean houses are too big to study in the lab, Kakani decided to perform similar experiments in the open ocean, using MBARI’s remotely operated vehicles (ROVs).

When she discussed this experiment with Postdoctoral Fellow Anela Choy—who studies the movement of plastic through the ocean—they realized that in-situ feeding experiments using plastic beads could also shine light on the fate of microplastics in the deep sea. Read more…

How do you tag a jellyfish?  

They’re so soft—so squishy! Where to put a tag—and why bother? Questions like these moved scientists from the Monterey Bay Aquarium, the Monterey Bay Aquarium Research Institute (MBARI), Hopkins Marine Station and other institutions around the world to publish the first comprehensive how-to tagging paper for jellyfish researchers everywhere. This missing manual was long in the making

A wild sea nettle swims off Point Lobos near Carmel. Photo ©Bill Morgan

Tommy Knowles, a senior aquarist at Monterey Bay Aquarium, explains why.  Historically, ocean researchers demonized jellies as “blobs of goo that hurt you,” and that interfered with scientific gear. That changed in the  latter part of the 20th century as scientists grew keen to understand entire ecosystems, not just individual plants and animals. Knowing who eats what, how, where and when, they learned, is critical for conservation.

Jellyfish, however, remained a very under-appreciated member of the ecosystem for years, largely because so little was known about them.

Senior Aquarist Tommy Knowles and his colleagues work in the lab and in the filed to advance jellyfish science. Photo by Monterey Bay Aquarium/Tyson Rininger

“People didn’t know how to keep them alive in the lab or even on the boat,” says Knowles. Today, the field is coming into its own at a time when climate change has added urgency to the need to understand ecosystems in order to preserve ocean health.

A growing subject of interest

Understanding jellies is a concern for fisheries managers, too, since some jellyfish species prey upon the young and compete for food with the adults of commercially important fish. Other jellies impact tourism when blooms of stinging species foul beaches.

It’s not all negatives. We know that jellyfish play important roles in healthy marine ecosystems, by sheltering juvenile fish and crabs under their swimming bells, and nourishing hundreds of ocean predators. Jellies are a significant food source for ocean sunfish (the largest bony fish on the planet) and the endangered Pacific leatherback sea turtle, California’s state marine reptile.

A barrel jellyfish (Rhizostoma octopus) is tagged by a diver with an accelerometer using the “cable tie” method. Courtesy Sabrina Fossette/NOAA

As with other marine species that live and travel underwater—out of sight of human researchers—electronic data tags are useful tools for tracking jellies’ movements. Which gets back to the question: Just how do you tag a jellyfish? Read more…

Our best Conservation & Science stories of 2016

It’s been an exciting year for ocean conservation at the Monterey Bay Aquarium.

We’ve shared how our care for the animals in our living collections—including snowy ploverscomb jellies, ocean sunfish and Pacific seahorses—contibutes to the conservation of their wild kin.

MBA_plover06
The Aquarium helps rehabilitate threatened Western snowy plovers.

We’ve visited the Canadian cousins of Monterey Bay’s sea otters, explored how sea otters use tools, and assisted scientists working to decode the sea otter genome.

We’ve collaborated with our colleagues in Baja, Mexico on a number of conservation missions—one of them involving ancient shark mummies. And we joined forces with U.S. aquariums and zoos to call for stronger protections for the endangered vaquita porpoises of the Gulf of California.

As 2016 comes to a close, let’s look back at the top 10 highlights from this blog:

White shark GIF_MBA
A white shark approaches schooling sardines.

10. Camera to Crack a White Shark MysteryOur senior reseach scientist teamed up with the Monterey Bay Aquarium Research Institute for a high-tech mission: to capture video footage of great white sharks in their most mysterious habitat.

“Some of the engineering team said it was an impossible job,” MBARI Engineer Thom Maughan recalled. “But I’m attracted to those opportunities.”

Read more…

Julie Packard: A bold vision for ocean health

Monterey Bay Aquarium Executive Director Julie Packard, who also sits on the board of the David and Lucile Packard Foundation, offered a powerful vision of hope for the future of the ocean Friday morning at the third Our Ocean Conference convened by Secretary of State John Kerry  in Washington, D.C.

Julie Packard at Our Ocean 2016
Julie Packard at Our Ocean 2016

Julie shared the stage with other leading ocean philanthropists as she announced the Packard Foundation’s five-year, $550 million commitment to advance ocean science, protection and effective management. She held up Monterey Bay as an example of the transformation that’s possible in ocean health with an investment of time and energy to shape a thriving future for this vital living system.

For all their success in driving environmental improvements on land, foundations and philanthropists “over time we realized something was missing—the ‘other’ three-quarters of the planet, 99% of living space on Earth and the most prominent feature on this planet: the ocean,” Julie said.

Lunge-feeding humpback whales in Monterey Bay. Photo by Tyson Rininger
Lunge-feeding humpback whales in Monterey Bay. Photo by Tyson Rininger

Monterey Bay demonstrates—in dramatic fashion—what’s possible, she said. Its whales, sea otters and elephant seals were hunted to near-extinction, and the sardines that put Cannery Row on the map disappeared in “one of history’s most famous tales of fishery collapse.”

The wildlife is back, the bay’s ecosystems are robust, “Monterey Bay is now one of most studied pieces of ocean on the planet and California continues to be an incubator for ocean and climate solutions,” Julie said.

Read more…

Camera to crack a white shark mystery

The idea seemed like a long shot: Build a video camera that could attach to a great white shark for months at a time, withstand ocean depths of more than 3,000 feet, and sense the shark’s movements to selectively capture footage of its behavior.

But Monterey Bay Aquarium Senior Research Scientist Salvador Jorgensen, a white shark expert, thought it might have a chance if he joined forces with the talented minds at the Monterey Bay Aquarium Research Institute (MBARI).

“Some of the engineering team said it was an impossible job,” MBARI Engineer Thom Maughan recalls with a smile. “But I’m attracted to those opportunities.”

So Thom and Sal teamed up on a high-tech mission: to capture video footage of great white sharks in their most mysterious habitat.

Read more…

Untangling comb jelly culture

Try as she might, MacKenzie Bubel just couldn’t satisfy the baby comb jellies.

The aquarist was attempting to spawn a species called Mnemiopsis leidyi—ghostly-looking little creatures native to the Gulf of Mexico—in the Aquarium’s Jelly Lab. She tinkered with variables like water temperature, salinity and light exposure.

TR16-577
Aquarist MacKenzie Bubel works in the Jelly Lab with lobed comb jellies (Bolinopsis infundibulum).

“We did some wacky stuff to get the conditions perfect,” she says, “but they weren’t doing as well as we’d hoped.”

That changed when our staff aquarists, in collaboration with University of Miami assistant professor William Browne, pioneered an efficient way to culture comb jellies en masse. The breakthrough—which we’re sharing with our colleagues—could eliminate the need for aquariums to collect comb jellies from the wild. It could also pave the way for deeper scientific study of these little-understood animals.

Read more…

MBARI’s new ear on the sounds of the ocean

Researchers at the Monterey Bay Aquarium Research Institute (MBARI) have learned a lot about Monterey Bay using robotic submersibles to look deep below the bay’s surface. Now they can listen to the bay as well, using an ultra-sensitive underwater microphone. Sounds recorded by this hydrophone have already provided surprising information, including evidence that beaked whales, though rarely seen, are common in the outer bay.

MBARI placed a deep-sea hydrophone on the seafloor using a remotely operated vehicle. The green cable carries power to the hydrophone and data back to shore. Photo courtesy MBARI
MBARI placed a deep-sea hydrophone on the seafloor using a remotely operated vehicle. The green cable carries power to the hydrophone and data back to shore. Photo courtesy MBARI

In July 2015, MBARI researchers installed a broadband hydrophone on Smooth Ridge, about 30 kilometers (18 miles) from shore and 900 meters (3,000 feet) below the sea surface. Since that time, signals from the hydrophone have been relayed back to shore in real time, 24 hours a day, using MBARI’s cabled ocean observatory, the Monterey Accelerated Research System (MARS).

The new hydrophone doesn’t look very impressive. It’s just a metal cylinder about two inches in diameter, mounted on a metal tripod on the muddy seafloor. But it is extremely sensitive and can pick up a vast range of sounds, including those too low and too high for humans to hear.

A spectrum of sound

“We’re trying to characterize the soundscape of Monterey Bay,” says John Ryan, the biological oceanographer in charge of the project. “This means looking at the whole spectrum of sounds that we record and identifying all of the phenomena they represent. This includes biological sounds such as vocalizations of marine mammals, the sounds of physical processes such as wind and rain, and the sounds of human activities.”

MBARI’s deep-sea hydrophone is located on Smooth Ridge in the Monterey Canyon, about 30 kilometers (18 miles) from shore. Base image: Google Earth
MBARI’s deep-sea hydrophone is located on Smooth Ridge in the Monterey Canyon, about 30 kilometers (18 miles) from shore. Base image: Google Earth

Most adults (at least those who haven’t attended too many rock concerts) can hear sounds from about 20 Hertz (the low rumble of an earthquake) up to 16,000 Hertz (the high-pitched buzzing of a mosquito). The new hydrophone can pick up sounds ranging from 10 Hertz to 128,000 Hertz.

During a recent meeting with underwater acoustics experts, Ryan played a few of the distinctive sounds recorded with the hydrophone.

Here’s a recording of dolphins:

 

And here’s one of humpbacks:

Read more…

%d bloggers like this: