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The Surprising Consequences of a Seaweed Switcheroo – Hakai Magazine



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From Australia to the Arctic, kelp forests are disappearing as the ocean heats up. But in some places, such as in the chilly waters off England’s southwest coast, the struggling kelp ecosystem isn’t collapsing entirely. Instead, it’s being replaced. Over the past 80 years, once-abundant forests of the local cold-water kelp Laminaria hyperborea have slowly been overtaken by its warm-water cousin L. ochroleuca. Scientists aren’t sure yet how the newcomer is changing the ecosystem, but marine ecologist Daniel Smale is diving in to find out.

Smale grew up snorkeling these waters. He’s been observing the slow change of the kelp forests for nearly three decades—first as a teenager freediving to watch spider crabs, then as a scientist surveying the ecosystem. Certain spots once teeming with life now feel different, he says. Not devoid of life, but less bustling—a little less vibrant.

As the foundational species in kelp forests, kelp provides the structure and habitat that undergirds the ecosystem. The species of kelp affects what other organisms live there and how nutrients are used. Yet while much research has been conducted on what happens when a kelp forest disappears, little has been done on what happens when one kelp species is replaced by another. “These subtle shifts can go undetected or overlooked,” says Smale, who now works at the Marine Biological Association of the United Kingdom.

To discern how an ecosystem responds when a new kelp comes to town, Smale, in a new study, compared kelp forests at four sites around southwest England with two in Scotland, where the water is cooler and the warm-water kelp hasn’t yet crept in. The work shows that the replacement of L. hyperborea with L. ochroleuca can fundamentally change what organisms live in the ecosystem and cut the abundance of life in kelp forests.

The range of the cold-water kelp Laminaria hyperborea (first photo) historically extends from Portugal to the northern reaches of Norway. Laminaria ochroleuca (second photo), on the other hand, typically thrives in warmer southern waters in the Mediterranean and has only in recent decades crept up to Ireland and the United Kingdom. Photos courtesy of Daniel Smale

While his study focused on two kelp species and a few study sites, Smale says the general process—of a new kelp species encroaching on the historically dominant one—is likely playing out surreptitiously along many coastlines.

The sharp declines can be explained by the fact that L. hyperborea is an excellent host. A relatively unusual trait for kelp, it supports a robust growth of red algae on its brown rubbery surfaces. These red algae, in turn, support a thriving community of worms and gastropods, mollusks, and sea stars that feed fish and other hungry animals. In contrast, the warm water kelp L. ochroleuca had much less life growing on and around it.

In laboratory work examining kelp collected from their study sites, Smale and his colleagues showed how the replacement of one kelp with another leads to a huge difference in the biodiversity of the ecosystem. The cold-water kelp, they found, can support upward of 50 grams of red algae each. The warm-water kelp, in contrast, had almost none. This difference translated up the food chain. The cold-water kelp supported up to 375 invertebrates each, while a similarly sized warm-water kelp maxed out at 25.

This difference was clear in the field, too. The Scottish control sites, dominated by L. hyperborea, had about five times as many invertebrates as the English sites with L. ochroleuca. Because these invertebrates are food for fish and other species, the potential consequences are sweeping.

“The idea that changing from one species to another that’s relatively similar can have such profound effects is just fascinating,” says Jarrett Byrnes, a marine biologist at the University of Massachusetts Boston who was not involved in the research. “It’s a subtle shift that leads to profound changes that could amplify as you go up the food chain.”

Because kelp species swaps are far less studied than kelp forest loss, however, the full long-term impacts on everything from coastal fisheries to carbon sequestration remain unknown.

“It opens up a wealth of research that needs to be done as we watch our planet change,” says Byrnes.

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Perseid meteor shower: when to catch it in Manitoba | CTV News – CTV News Winnipeg



The peak of a spectacular space light show is expected to happen by the end of the week.

The Perseid meteor shower is expected to be at its best and brightest the night of Aug. 12 going into the morning of Aug. 13.

Scott Young, an astronomer at the Manitoba Museum, said this is an annual event that will produce dozens of shooting stars throughout the night.

“Every meteor is a piece of dust from outer space that is crashing into the earth at tremendous speed and basically vaporizing in a poof and a flash of light, and that it is what we see as a meteor,” he said. “On certain nights of the year, the earth in its orbit around the sun actually goes through a cloud of dust, sort of like an interplanetary dust bunny, essentially, and all that dust hits on the same night … and so we are basically crashing through the dust left behind by a comet.”

The cloud of dust was left behind by the comet Swift-Tuttle, which last passed by the earth in 1992. Since then, the meteor shower has reached its peak between Aug. 11 and 13.

For those who are looking to enjoy the meteor show, Young suggests people get away from city lights, especially this year as the shower also coincides with a full moon.

“The moon can wash out those fainter meteors, and also if you are in the city, city lights will also wash out those fainter meteors. If you want to see the best show, you want to go late Friday after midnight, into the early morning hours of Saturday.”

If people can’t see the shower that night, Young says not to worry as the Perseid meteor shower is already happening right now and will continue to the end of August. As long as people are away from bright lights, Young says they should be able to see some shooting stars.

He recommends going to places like Birds Hill Provincial Park to enjoy the shower, but noted if people can find a place that is away from direct light, whether that be a park within the City of Winnipeg, or even a person’s backyard, he suggests people will be able to see something.

Once the meteor shower is over, however, Young does have a cautionary tale to share.

“We get dozens calls of people seeing an interesting rock on the ground and thinking that they’ve found a meteorite. There are no meteorites that will fall and actually land on the ground from this shower. These are little pieces of dust and they completely vaporize in the atmosphere. You might find meteorites out there, but they are very, very rare and so don’t get all excited about every rock that you find after this. The odds are it’s a meteor-wrong and not a meteorite.”

Young said weather-permitting, the Manitoba Museum will livestream the shower on its social media channels.

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NASA’s Hubble Space Telescope captured two festive-looking nebulas – Tech Explorist



The image shows NGC 248, about 60 light-years long and 20 light-years wide. They are two nebulas, situated to appear as one. The nebulas, together, are called NGC 248.

Initially discovered in 1834 by the astronomer Sir John Herschel, NGC 248 resides in the Small Magellanic Cloud, located approximately 200,000 light-years away in the southern constellation Tucana.

Small Magellanic Cloud is a dwarf galaxy that is a satellite of our Milky Way galaxy. The image is part of a study called Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE).

The dwarf satellite galaxy contains several brilliant hydrogen nebulas, including NGC 248. Intense radiation from the brilliant central stars is heating hydrogen in each nebula, causing them to glow red.

The study’s principal investigator, Dr. Karin Sandstrom of the University of California, San Diego, said“The Small Magellanic Cloud has between a fifth and a tenth of the amount of heavy elements that the Milky Way does. Because it is so close, astronomers can study its dust in great detail and learn about what dust was like earlier in the history of the universe.”

“It is important for understanding the history of our galaxy, too. Most of the star formation happened earlier in the universe, at a time when there was a much lower percentage of heavy elements than there is now. Dust is a critical part of how a galaxy works, how it forms stars.”

The image is part of a study called Small Magellanic Cloud Investigation of Dust and Gas Evolution (SMIDGE). The data used in this image were taken with Hubble’s Advanced Camera for Surveys in September 2015.

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When To See An ‘Earth-Grazer’ This Weekend: Don’t Write-Off The Perseid Meteor Shower, Says Expert – Forbes



If you’ve ever laid down a blanket or set up a lawn chair to watch a meteor shower there’s a good chance it was to watch the Perseids.

Due to peak at 01:00 UT on Saturday, August 13, 2022, normal advice would be to be outside at that time (in Europe) or just as soon as its gets dark on Friday, August 12 (North America).

As I’ve already reported, this year the Perseids coincides with a full Moon, so all but the brightest meteors and “fireballs” (larger, brighter meteors) will be visible. So from the 50-75-or-so “shooting stars” you might normally see during the peak of the Perseids only a few—albeit bright—meteors will be visible.

It’s almost not worth the bother, I said, advising you to go watch this instead next weekend.

However, there is another opinion. In an article published on the American Meteor Society’s website, fireball coordinator Robert Lunsford says that despite the bright full Moon visible meteor rates during the peak of the Perseid meteor shower will be better than 95% of all other nights this year.

When to see the Perseid meteor shower

“Most of the Perseid meteors are faint and bright moonlight will make it difficult to view,” he writes. “Despite the glare of moonlight, the Perseids produce many bright meteors that can still be easily seen despite the bright moonlight.”

He also advises two great times to watch for shooting stars—just after sunset on Friday, August 12 and just before dawn on Saturday, August 13.

Perseids: ‘Earth-grazers’ just after sunset

You’ll need patience, but to see an “Earth-grazer” is unforgettable.

Just after sunset is actually thee worst time in terms of numbers of shooting stars you might see, but the few that do come your way this time of night are special.” The reason is that they just skim the upper regions of the atmosphere and will last much longer than Perseids seen during the morning hours,” writes Lunsford. “Most of these “earth-grazing” Perseids will be seen low in the east or west, traveling north to south.”

Perseids: ‘shooting stars’ before dawn

The activity from the Perseid meteor shower will peak where you are as the radiant—the constellation of Perseus—rises higher into the night sky. “Theoretically, the best time to watch the Perseids is just before the break of dawn when the radiant lies highest in a dark sky,” writes Lunsford. That’s about 04:00 local time, though he also reveals that experienced observers often say the hour between 03:00 and 04:00 is usually the best.

Perseids: ‘shooting stars’ in a moonless sky

If you want to look for Perseids in a dark, moonless sky then you’re mostly out of luck this year. By the time the full Moon is rising long after midnight the meteor rates will have vastly reduced, though it may be worth shooting star-gazing after August 19, 2022.

When is the Perseid meteor shower in 2023?

The Perseid meteor shower will next year peak—in thankfully moonless skies—at around 07:00 UT on August 13, 2023 (so 03:00 EST and midnight PST), which will be ideal for North America.

Wishing you clear skies and wide eyes.

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