The deep impact of microplastic

 

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There’s a vast ecosystem stretching far below the ocean’s surface — one where the light dims, the pressure mounts, and life takes on forms that can seem downright alien. But even there, a place that seems a world apart from human society, our plastic trash is building up.

Scientists from the Aquarium and MBARI sampled microplastic pollution in the deep waters of Monterey Bay using the ROV Ventana. Photo courtesy MBARI

In the deep sea, it’s a challenge to study where that plastic accumulates and how it affects animals. So scientists at the Monterey Bay Aquarium and our partners at the Monterey Bay Aquarium Research Institute (MBARI) launched an ambitious collaboration.

The resulting study, which examined microplastic in the waters of Monterey Bay, was published June 6 in the journal Scientific Reports.

“We designed this study to answer a fundamental gap in our knowledge of marine plastic once it reaches the ocean,” says lead author Anela Choy, a former MBARI researcher and now a professor at the Scripps Institution of Oceanography in San Diego.

MBARI researchers collected larvaceans and their mucus feeding filters using its remotely operated vehicles. Photo courtesy MBARI.

The research team gathered data by using remotely operated vehicles (ROVs), robotic submarines designed by MBARI engineers, to collect water samples at depths from 200 to 600 meters (about 650 to 2,000 feet).

They also searched for plastic in animals with important roles in the marine food web: pelagic red crabs; and tadpole-like creatures called giant larvaceans, which surround themselves with clouds of mucus that capture food — and, as the researchers discovered, plastic.

“Problems like this are extremely complicated. To try and figure out how to solve them, you need a lot of different tools,” says Aquarium Chief Scientist Kyle Van Houtan, who co-authored the paper with Anela and nine others, tapping fields from physical chemistry to marine ecology. Continue reading The deep impact of microplastic

Clash of the titans: white sharks vs. orcas

When orcas and white sharks cross paths, only one can prevail as the true apex predator. New research from the Monterey Bay Aquarium published in Nature Scientific Reports details these rare, sometimes brutal encounters — and their ecological implications.

A new study illustrates what happens when orcas and white sharks encounter each other in the wild. Photo © Jim Capwell/www.divecentral.com

It’s a study decades in the making because observations of the two creatures interacting is a rarity.

Scot Anderson, a white shark expert and seasonal researcher for the Aquarium, still remembers one such run-in more than 20 years ago near the Farallon Islands, a short boat ride west of downtown San Francisco.

“The first time it happened was kind of shocking to everybody,” Scot says. “Before we had seen anything like that, people would ask, who’s the baddest predator?”

White sharks are seasonal visitors to the Farallon Islands, where they prey on elephant seals and other pinnipeds. Photo courtesy NOAA

The first scorecard came on October 4, 1997, when orcas killed and partially ate a white shark within view of a whale-watching boat. Scot was heading out from nearby Bolinas when he heard what was happening over the radio.

“We just went straight there,” he says. “We got there right as it was finishing. I saw the two orcas sticking their heads out of the water and squealing like they do when they have a kill. And the shark just sank away.” Continue reading Clash of the titans: white sharks vs. orcas

New insights to help young white sharks survive

What can scientists studying white sharks learn from an expert on mountain lions? As it turns out, quite a lot.

Monterey Bay Aquarium and its research colleagues have been tagging juvenile white sharks in southern California since 2002. Now they’ve gained new insights into white shark survival from those data tags. Photo courtesy Steve McNicholas

Such a collaboration is on display in new research published in the Journal of Applied Ecology. Models that estimate survival rates for top predators on land, according to the study, can also work in the ocean. The research also revealed important safeguards that can help protect white sharks while they’re young and vulnerable.

At the heart of the effort was the work of lead author John Benson. Before taking his current role as a professor at the University of Nebraska, John was a post-doctoral researcher at the Monterey Bay Aquarium, working with senior research scientist Sal Jorgensen.

Young white shark on exhibit at Monterey Bay Aquarium.

“We always learn things from adjacent fields,” says Sal, who specializes in white sharks, and who coauthored the paper along with six others. “John made his name studying mountain lions in Southern California.”

John’s past work also involved black bears in Louisiana, panthers in Florida, wolves and coyotes in Canada, and moose and their various predators in Alaska. After so much experience on land, John saw working with Sal at the aquarium as a chance to—as the saying goes—get his feet wet. Continue reading New insights to help young white sharks survive