2 . In nature, octopuses (章鱼) hunt mainly with their sense of touch, using their eight arms to feel out their environment for hidden creatures. Researchers at the University of Minnesota recently studied a different way octopuses hunt—when they identify prey (猎物) based on sight. The study findings show that the marine creatures are quite consistent and methodical in how they approach prey.

Lead researcher Trevor Wardill and his team placed California two-spot octopuses into water tanks, hiding them in caves where they would have one eye looking out. They then placed either fiddler crabs or white shrimp in the tanks to see how the octopuses would try to catch them, capturing the interactions on video. The crabs and shrimp behave differently when trying to escape from predators (捕猎者), so using both species gave the researchers an opportunity to see whether this led the octopuses to use a different arm for hunting depending on the prey.

Wardill’s team found that the octopuses almost always used the same arm to grab their prey. Specifically, the second arm from the middle of the octopuses’ body, on the same side of their body as the eye, caught the prey. If they needed more arms to grab prey, they would use the ones next to the second arm.

The octopuses also attacked differently depending on the prey. When faced with crabs, an octopus would move suddenly on top of the crab with its whole body. However, when catching shrimp, the octopuses would take one arm and reach out very slowly toward the shrimp, then grab it and latch (缠住) onto it with its other arms to pull it in.

Wardill and his team hope to do more research. They want to study the octopus’s brain as it attacks pre y to develop a better understanding of what role the creature’s nervous system plays in selecting the arms it uses.

5 . Third graders from Wolfsville Elementary School spent Monday afternoon getting their hands dirty and their shoes wet during an informative trout release (鳟鱼放生).

The trout, which the students had been ________in their classroom since last December, were ________ ready to be released into their natural environment. The students carefully ____ them from a big container to a red plastic cup to the creek (溪). They then ________ the trout fingerlings (仔鱼) they’d been watching over for five months.

Wolfsville Elementary has been doing a trout release ________ spring for the past decade as part of a national________called “Trout in the Classroom”, which provides students with trout eggs to ________and eventually release into water as fish.

Through the partnership, students learn various________such as water pH, animal lifecycles and environmental science, said Rebecca Butler, Wolfsville Elementary’s third grade teacher. “We try to get them outside and away from video games, and hopefully they________ that clean water is important and ________ else is going to take care of our resources, so they learn to care for them,” Butler said.

McKinna Hidalgo, a third grader at Wolfsville, said she________ letting the trout go in the water and seeing them________ away, after first meeting them as ________.

The favorite part for Hidalgo’s classmate Macie Lader, however, was getting to go into the creek. Her socks and shoes were _________, but she didn’t care. Right before moving on to her next station, Macie took off her _________, dumped (倾倒) all the water out and flashed a wide smile.

9 . The cold, wet weather of winter often puts out any wildfires that are still burning, but not in the far North areas, such as Alaska, Canada, and other parts of North America. Some forest fires just don’t die in these places. Think of the fires as “zombies” (僵尸): Scientists do. When summers are warmer than normal, some fires can hide through the winter. They burn dead plant matter and soils under snow. In May 2021, scientists reported their work to a scientific journal. The scientists saw that zombie fires are rare but they could become more common as the world warms, the study warns.

“Some years, new fires were starting very close to the previous year’s fire,” explains Rebecca Scholten. She studies Earth and environmental sciences at Vrije University Amsterdam in the Netherlands. The new fires made scientists wonder how often fires might survive the winter. The scientists started by combing through firefighter reports. Then they compared these with satellite images of Alaska and northern Canada. The scientists looked for fires that began close to fires from the year before. They also focused on blazes starting before the middle of summer. Random lightning or human actions spark most fires in the area, Scholten says. But those fires happen later in the year.

Zombie fires accounted for less than 1 percent of the total area burned by fires from 2002 to 2018. But it changed from year to year. Take 2008, for example. A zombie fire burned Alaska that year. It caused almost one-third of fire damage that year. One clear pattern emerged: Zombie fires were more likely to happen after very warm summers. High temperatures may allow fires to reach more deeply into the soil. Such deep burns are more likely to survive to spring.

The zombie fire threat could grow. The climate is warming. Forests in the far North already are warming faster. “We’re seeing more hot summers and more large fires and intense burning,” Scholten says. Plus, zombie fires could cause more issues. The fires release huge amounts of greenhouse gases. These trap heat in the Earth’s atmosphere. The atmosphere is a layer of gases that surround the Earth. Scholten’s research could help fire management. Firefighters would know to check for them after warm summers.

10 . A team of scientists recently published one of the most comprehensive efforts yet to understand just how much carbon great whales absorb from the ocean, and the value that presents in the fight against climate change.

“Whales are large-bodied animals, and they live for a long time. Many of them migrate over vast distances,” said study leader Heibi Pearson, a marine biologist at the University of Alaska Southeast. “And so they have the potential to have these huge impacts on the ecosystem, including the carbon cycle.”

In their most direct impact, whale bodies hold an enormous amount of carbon that would otherwise be in the ocean or atmosphere. Twelve great whale species hold an estimated 2 million tons of carbon in their bodies, the authors found.   

And that’s just the living members of the whale family. Another 62,000 tons of carbon is kept under the sea every year in the form of whale falls. When a whale dies in open water and sinks into the deep, a lifetime of collected carbon goes with it. It can take up to 1,000 years for water and elements at the bottom of the sea to cycle back up to the surface, which means that carbon is effectively sequestered for that long.

In addition, whales’ waste facilitates the growth of organisms at the base of the marine food chain, promoting the growth of carbon-consuming life throughout the ecosystem.     

However, whale populations still haven’t recovered from the destructive effects of industrial whaling. Commercial hunting in the 19th and 20th centuries decreased the total mass of whales on the planet by 81%, according to the authors.

“Whales alone are not going to solve climate change, but thinking about whales as playing a role in the carbon cycle can help motivate whale conservation,” said Andrew Pershing, a co-author of the study. “There are a lot of win-wins there, and I think that’s very true of a lot of natural climate solutions.”