How Invasive Crayfish Help More Mosquitoes Thrive

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iStock

When invasive species somehow find their way into an environment where they don’t belong, they can disrupt everything from the food web to public health.

Recently, researchers at UCLA and other California institutions discovered an unwelcome squatter that might directly affect the spread of mosquito-borne disease. It’s the red swamp crayfish, a tasty delicacy often found in gumbo that may also be allowing mosquito populations to thrive.

Native to the southeastern U.S., the crayfish are now found in California. While investigating their damaging ecological presence, scientists made a chilling observation: In streams where crayfish concentrations were high, there was a noticeable spike in the number of mosquito larvae. They found something else, too—a sharp decline in the larvae-eating dragonfly nymphs that they would expect to see in the area.

In the paper, published in Conservation Biology, lead author Gary Bucciarelli observed 13 streams in the Santa Monica Mountains. Eight had crayfish populations and were high in mosquito larvae but low on dragonfly nymphs. Five crayfish-free streams had more nymphs and fewer larvae.

In a lab experiment putting the crayfish, mosquitoes, and dragonflies in proximity, Bucciarelli watched as the dragonfly nymphs—normally happy to prey on mosquito larvae—kept their distance in the presence of crayfish, apparently spooked by the crustaceans. In the wild, high concentrations of crayfish appear to be interrupting the dragonflies' hunting habits, allowing more mosquitoes to roam unchecked.

That’s not great news for humans. Mosquitoes are notorious for spreading viral diseases like West Nile, Zika, and malaria. In Los Angeles, where the mosquito population could conceivably get a boost, 15 of the 16 mosquito species can harbor pathogens that pose a threat to public health.

No one is quite sure how crayfish spread to the area—it’s possible fishermen used them as bait decades ago—but it's likely their presence will continue interfering with native species. In 2015, a nonprofit backed by the California Department of Fish and Wildlife started removing crayfish from the Santa Monica streams using traps set by volunteers. The captured crayfish were sent to Malibu to become snack fodder for opossums and raccoons. But it’s a sizable task. Roughly 600 crayfish might be caught in a given day out of the millions thought to inhabit the waters.

Conservationists might soon pursue more aggressive means to combat the crayfish's damaging ecological footprint. In addition to scaring dragonflies into inaction, they can threaten the integrity of underwater dams by burrowing and consume plants that help purify the water.

h/t National Geographic]

Oregon Launches the Country's First State-Wide Refillable Beer Bottle Program

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Being a frequent beer drinker doesn't just affect your waistline. It's also not good for the environment—all those cans and bottles add up. But Oregonians soon won't have to feel guilty for the bottles piling up in their trash cans, because the state just launched the first state-wide refillable beer bottle program in the U.S., as NPR and EarthFix report.

Oregon breweries are selling their beer in thicker, heavier beer bottles that customers can return to be cleaned and refilled, just like the milk bottles of yore. Seven craft breweries whose beers are available in stores across the state are currently participating in the refillable bottle program, but the distinct bottles can be used and refilled at any brewery in the state, and the program will likely expand in the coming years.

The bottles, stamped with the word "refillable," are made from recycled glass and can be reused up to 40 times. The design was developed by the Oregon Beverage Recycling Cooperative, and customers can drop them off at any of the group's 21 redemption centers. The organization also runs the state's general container deposit-refund system, so customers can bring them to the same locations as any other recyclables.

The thicker shape allows them to be separated out from other recyclables that get dropped off at bottle deposit sites, ensuring that they get sorted out to be refilled rather than recycled with standard glass bottles.

Oregon passed the first state bottle bill in the nation in 1971 as a way to encourage recycling. In 2018, the state increased the bottle deposit from 5 cents to 10 cents, hoping to increase redemptions. About 73 percent of metal, glass, and plastic recyclables were actually redeemed in 2017, up from 64 percent in 2016.

While refillable beverage containers aren't the norm in the U.S., other countries are far ahead of us. Some provinces in Canada have nearly a 99 percent return rate for their refillable bottles, and the average bottle is reused 15 times. Most beer in Germany is sold in mehrweg, or reusable, bottles, and consumers can return them to any store that sells reusable-bottle beer to get their deposit back.

Though the Oregon program is an environmental boon, the carbon savings won't be as high as they could be. Oregon doesn't yet have a bottle washing facility to process the refillables, so they currently have to be shipped to Montana for washing. Eventually, the program will set up some of these washing facilities in-state, increasing its utility.

[h/t NPR]

You Can Visit Any National Park For Free This Saturday

Mark Ralston, AFP/Getty Images
Mark Ralston, AFP/Getty Images

Looking for something to do this weekend? Within driving distance of one of the country's more than 400 national parks? The timing might work out. On Saturday, September 22, the National Park Service will be celebrating National Public Lands Day by offering free admission to any national park that normally charges an entrance fee.

Established in 1994 by the National Environmental Education Foundation, National Public Lands Day is held annually on the fourth Saturday in September. The day is set aside to recognize and encourage stewardship of green space in individual communities. If you see an opportunity to volunteer that day, you can get a voucher good for admission on a day of your choosing.

Admission to federally owned parks during peak season averages $30 at the 117 locations that require payment for access. Recently, the National Park Service had considered raising the fee to $70 at 17 of the busiest parks. The potential move would help address maintenance and other costs, but it's drawn criticism from conservation groups arguing the locations should remain affordable to visitors. In the end, the NPS decided to raise prices by $5 for one-time entry, or $5 to $10 for an annual pass, though some fees won't rise until 2020.

You can search for parks by state or by activity using the National Park Service Find a Park search engine here. Note that any additional charges for camping or other attractions aren't included in the promotion.

Can't make it this weekend? The parks are open for a fee-free day four times in 2018, down from 10 in 2017. The next date is November 11, in honor of Veterans Day.

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