This Week in Ice, Oct. 10-14

I’m posting a littler earlier this week—so much has happened in ice.

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A highlight of our SNOWBIRDS Transect research cruise was watching the Adélie penguins, by far the most entertaining and—I have to say it—cute creatures I’ve ever seen. One couldn’t help but be enchanted and amused by these little fellows as they bob their heads and chatter, waddle-running on little legs and belly-scooting across the pack ice, tumbling over their own feet and each other.

So, it’s gut-wrenching to read that in a colony of around 36,000 Adélie penguins, only two chicks have survived. The others starved to death. Sea ice conditions in that area forced adult penguins to travel much farther to find food. Next week, environmental groups and officials will meet to discuss the creation of a Marine Protected Area off eastern Antarctica, prohibiting fishing of krill, thereby helping relieve stress on some penguin colonies and other marine life.

A couple of weeks ago, I talked about the Maud Rise polynya, also known as the Weddell polynya, which opened up in the Weddell Sea about a month ago. A polynya is an area of open water within the ice pack.

The Maud Rise polynya, which I read has grown to about 80,000 square km (30,000 square miles), is currently about the size of South Carolina, Maine, Lake Superior, Tasmania, or Switzerland, depending on where you read this news–which finally hit the mainstream this week.

It’s the dark blue patch near the top of the image.

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It looks a bit like a whale or shark…

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I believe this image is from Sentinel 1.

News reports say scientists are “puzzled” or “mystified” about what’s causing it, since the polynya is far from the sea edge. However, the Antarctic Report notes that the seamount (underwater mountain) for which the polynya is named rises 3,500 m deep to 1,700 m deep, creating eddies, which bring warmer water closer to the surface.

Such openings in sea ice affect our global climate. And here’s a (fun?) related story.

There is no doubt that as the planet warms, the sea ice extent is changing and/or acting in unexpected and troubling ways. Glaciers, too, are affected.

Satellite imagery has shown an upside-down canyon forming beneath the Dotson Ice Shelf. This video from the Center for Polar Observation and Modeling explains this process well:

 

Meanwhile, massive iceberg B-44, which calved (= broke off) from the Pine Island Glacier in September, has developed new cracks.

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So, it’s been a big week in ice—and, hopefully, one that makes you think.

To finish off, here’s something as mesmerizing as it is fascinating:

 

As always, I am not a scientist, just a writer/illustrator and science communicator passionately in love with sea ice. I welcome input and corrections by polar scientists as I learn more about this remarkable and vital part of our planet, and then bring this knowledge to a wider audience. 

Eelgrass Adventure

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This week’s science adventure took me to the watery underworld of Long Island Sound with scientists Mike Bradley and Scott Rasmussen as part of a US Fish and Wildlife Service research project. Our goal: to check the extent and health of eelgrass beds along the Connecticut and Long Island shores.

We pound across the Sound on a glorious autumn morning. Terns and gulls wheel and dive, feasting on jumping fish. It’s a perfect day for fishing, and we pass numerous small boats doing just that. Coastal New England, USA, is famous for its bountiful and diverse seafood.

“Eelgrass provides habitat for juvenile fish and shellfish,” says Mike. “So, if you like fish and shellfish, you should care about eelgrass.” Eelgrass also helps stabilize the sandy areas close to shore and in estuaries.

Prior to our adventure, Mike mapped the possible extent of eelgrass by studying dark patches near the shore from areal imagery–photographs taken of calm waters at low tide from a plane early this summer. Seaweed–known by scientists as macroalgae (because seaweed is actually large algae)–can also appear as dark patches. So, using an underwater video camera, we traveled along multiple straight lines–or transects–across each area, and Mike plotted where eelgrass was actually present.

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Mike plots eelgrass, while Scott maneuvers the video camera and cheery Tom Halavik, retired from the US Fish & Wildlife Service, drives the boat.

From the boat, eelgrass is a shifting golden-green tapestry beneath, and seaweed looks dark and foreboding. But viewed from below, eelgrass and seaweed beds are a colorful, gently swaying, otherworldly forest. Clams and oysters litter the bottom, spider and green crabs scuttle and hide, and fish such as tautog hunt for prey.

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Tautog on the hunt

Mike will return numerous times to Long Island Sound to complete the survey of over 300 eelgrass beds, covering approximately 2,500 acres. The video and mapping data he collects will be used by biologists to monitor the health of eelgrass along this section of New England coastline.

Near the end of our journey, in a quiet aqua-watered cove of Plum Island, we were treated to a delightful encounter with up to twenty seals, who popped their heads up to study us before continuing to fish and play. It was a magical end to my eelgrass science adventure!

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Spot the seals!

Eelgrass Facts

  • There are 15 species of eelgrass–Zostera–and they are widespread along coastlines in the Northern Hemisphere, as well as parts of Australia and Africa.
  • Eelgrass needs significant sunlight to grow, so it’s found in shallow waters and does better in clear, not murky water.
  • Its success is also affected by water temperature and quality. As water temperatures increase while our planet warms, eel grass becomes less successful, which means habitat for juvenile fish and shellfish declines.
  • Increased nitrogen in the water–due to runoff from fertilizer, detergents, etc.–benefits macro-algae, which competes with eelgrass.

This project is a partnership between the Environmental Data Center of the University of Rhode Island and Suzanne Paton, Senior Biologist at Southern New England’s US Fish and Wildlife Service. The funding for this survey was provided by the EPA Long Island Sound Study, and the information will help evaluate water quality and habitat restoration projects that have been implemented over the years. This data will be compared to data collected in 2002, 2006, 2009, and 2012 by the US Fish & Wildlife Service in collaboration with the EPA to assess long-term trends and progress toward the restoration of this important habitat. 

Thanks, Mike Bradley, for taking me along!