Tag Archives: theNaturefiles

Changing Chesapeake Bay acidity endangers oysters

New research shows that the shell growth of Crassostrea virginica from Chesapeake Bay could be compromised by current levels of acidity in some Bay waters. (Photo/Chris Kelly, UMCES Horn Point Laboratory)

Growing up at the mouth of the Lynnhaven River in Virginia, where the river meets the Chesapeake Bay and the bay meets the ocean, I can’t tell you how many mornings I woke up and looked out my window to see neighbors wading in rubber boots, harvesting oysters from the beds just off our riverbank. For some, like my neighbors, oysters were a way to connect with the land and make a little extra dough. For others it was their livelihood. The act was something that just was. It never occurred to me that the oysters could one day be gone.

That’s why I was especially alarmed to read this new report from the University of Maryland Center for Environmental Sciences. Rising acidity levels in the Chesapeake Bay are making it harder for oysters to grow their shells. I’ve heard the news before that rising ocean acidity from sources such as carbon dioxide can spell disaster for marine wildlife, but this new study shows that acidity is rising faster in the Chesapeake Bay than in the ocean and having a measurable impact on Bay wildlife.

“With oyster populations already at historically low levels, increasingly acidic waters are yet another stressor limiting the recovery of the Bay’s oyster populations,” said marine biologist Dr. Roger Newell of the UMCES Horn Point Laboratory in a press release.

But don’t turn around to blame climate change just yet. The story is a bit more nuanced than that, though the source of the problem still has to do with us. In the saltier areas of the bay, the acidity is going up, leading to thin shell growth that makes oysters more vulnerable to predators, including crabs. But in more freshwater portions of the Bay, acidity is actually going down, said the study, which looked at more than 20 years of historical water quality data from the Bay.

The difference seems to be not atmospheric carbon dioxide, but the base of the food chain. In freshwater areas along the upper Chesapeake, sewage and agricultural runoff cause phytoplankton blooms, which consume carbon dioxide and lower acidity, said the study. Sounds good at this point right? Here’s the catch. As phytoplankton drift through the Bay, they are eaten by animals and other bacteria, releasing the carbon dioxide that the plankton so diligently consumed in the first place. This carbon dioxide lingers in the water, leading to spikes in acidity in the saltier regions of the Bay near the ocean.

“While these variations in acidity may improve conditions for shellfish in some areas, they may also magnify detrimental impacts in others,” said lead author Dr. George Waldbusser of Oregon State University in a press release. “What our study indicates is there may be an important shifting baseline and without better measurements we will fail to fully understand impacts on estuarine biota.”

Beyond the science itself, this study highlights how connected and varied our environment is. It lays out a pathway of human-induced consequences to an ecosystem, and teaches that we need to look beyond one-to-one cause and effect. Erin Voigt, an undergraduate student who worked on the study puts it well. “The complex response of oyster shell formation to temperature, salinity, and acidity highlights the need to understand how the entire ecosystem is changing, not just acidity,” she said.

And that ecosystem includes us.

You can view the article online in the journal Estuaries and Coasts.


Red squirrels are people too. They adopt

Red squirrel taking an adopted baby from nest. (Photo/Ryan W. Taylor)

In another life, I must’ve been a dog. Whenever I’m out walking and see a squirrel, I have an almost uncontrollable urge to see how close I can get to it before the scrappy rodent scrabbles up a tree. Inevitably, a staring contest ensues, which the squirrel usually ends up winning.

My suppressed animal urges aside, I do notice something kind of educational about squirrels. They tend to be alone. When they’re not, they are usually chasing each other like crazed maniacs in a not too friendly manner without regard to life or other happenings.

That’s why it might come as a surprise that they practice a typically human behavior – they adopt. And they adopt outside their social group. A new study by researchers at the University of Alberta determined that red squirrels will take in abandoned or otherwise parent-less young and raise them as their own, a seemingly altruistic act. The behavior turns out not to be as charitable as it sounds – the squirrels do get a survival perk. But the discovery is nonetheless an unusual one in the animal kingdom, with its own squirrely flare to boot.

Jamieson Gorrell, a Ph.D. student in evolutionary biology at the University of Alberta and lead of the study, was observing a population of Yukon red squirrels and noticed a lone female had taken a baby from an abandoned nest to raise as her own. When Gorrell sifted through 20 years of red squirrel research from the area, he found four other instances of the same behavior. Not only that, but in each account, the baby adopted was a relative.

Gorrell found that despite their antisocial tendencies, red squirrels are still able to recognize, and decide to care for, relatives. Right now the predominant notion is that the chitter-chatter squirrels screech out to mark territory or ward off others contains vocal clues about relativity. So an encroaching squirrel could hear the calls of another adult, and recognize kinship. If that other mother disappears, the encroaching squirrel may recognize the kinship of the abandoned nest and take action.

In addition to the novelty factor of the behavior, the study authors also state that this finding proves a long-standing evolutionary theory true. It is a concept known as Hamilton’s Rule, which suggests that despite “the law of the jungle and survival of the fittest,” animals can be altruistic.

Though for red squirrels, it’s a tempered altruism. The red squirrel is still helping out a member of its bloodline, and will only help one baby out of a litter. Adopting more than one is “out of the question,” according to the study, as the strain of adding more than one baby to a single mother’s already full house would outweigh any benefits.

You can read more about the study in the online journal Nature Communications, or visit this link http://www.redsquirrel.ca/KRSP/Media.html to get more info, cute pics, and free copy of the study.

Craniac Country: Nebraska’s Sandhill Crane Migration

Two girls in a jeep rumble around the country roads of Nebraska to check out the spring sandhill crane migration and can’t believe their eyes. Be careful. Watching this might make you a craniac.

Deep-sea volcano eruption captured in HD reveals first glimpse of ocean crust formation

The Jason remotely-operated vehicle (ROV) samples fluid at an eruptive area near the summit of the West Mata Volcano. The fluid sampling “wand” is approximately three feet long.  Image courtesy of NSF and NOAA.

The Jason remotely-operated vehicle (ROV) samples fluid at an eruptive area near the summit of the West Mata Volcano. The fluid sampling “wand” is approximately three feet long. (Photo/Courtesy of NSF and NOAA)

With bulbous burps of molten lava, roiling submarine steam and a thunderous roar, an ocean floor is born. In a scene straight from the origins of our planet, scientists have for the first time captured high definition video of the deepest recorded underwater volcanic eruptions. Researchers from NOAA and the National Science Foundation unveiled two short video clips, (one posted below), during a press conference today at the fall meeting of the American Geophysical Union.

The ocean floor is almost entirely formed by lava oozing from beneath, yet this process is poorly understood and never before observed in this way. “On our very own planet we haven’t seen lava flowing on the sea floor. We haven’t seen ocean crust being made,” said Joe Resing with the University of Washington and NOAA’s Pacific Marine Environmental Laboratory.

“It’s a spectacular process to watch,” said microbiologist Julie Huber with the Marine Biological Laboratory.

Vodpod videos no longer available.
more about “Deep-sea volcanic eruption“, posted with vodpod

The cacophonous bubbling mass of note is the West Mata submarine volcano in the Northeast Lau Basin, about a half a day’s ship ride from western Samoa. Almost two miles beneath the surface of the ocean lies a volcano about six miles long, four miles wide and one mile high that to best knowledge may have been erupting continuously for the past five months, according to the scientists at a press conference during the American Geophysical Union fall meeting.

Shrimpy smorgasbord – The environment is so new and acidic, hovering somewhere between battery acid and stomach acid, that not much has colonized the volcano yet, but hydrothermal vent shrimp are on the scene, along with fields of microbes for the shrimp to munch on. Not only do the tiny crustaceans appear to be early colonizers, but they come from far away. The species observed are the same ones found in Hawaii and Guam so may be dispersing from as far as 4,000 miles away, said Woods Hole Oceanographic Institute’s Tim Shank.

How underwater rock formations are created – Geology is often about looking at rocks frozen in time, now scientists can stop using their imaginations and see the process in action. One type of formation captured on video, known as Bonanite lavas, are thought to be among the hottest eruptions on Earth, and have previously only been seen long after they’ve cooled.

What they sound like – Scientists dangled a hydrophone from the remote-controlled submersible to record the roar of the volcano. If you know the basics of physics, water is an excellent conveyer of sound. The deep ocean might require earplugs.

Closing in on the action – Being underwater actually affords scientists a more intimate view of an active volcano. On land being so close to the source of an eruption would mean bye-bye for the curious cat or their equipment, but the oceanic environment provides enough buffer to see these eruptions from meters away as opposed to miles.

Roiling submarine steam,

%d bloggers like this: