NEVADA STATE GOVERNMENT (AP) — They found no sign of a mysterious sea monster, a thug in cement shoes or a long-lost treasure chest.
But scuba divers who spent a year cleaning up Lake Tahoe’s entire 72 miles (115 kilometers) of shoreline have taken with them what they hope will prove more valuable: tons and tons of trash.
In addition to removing 25,000 pounds (11,339 kilograms) of underwater litter, divers and volunteers have been carefully sorting and documenting litter types and GPS locations since last May.
The dozens of dives that ended this week are part of a first-of-its-kind effort to learn more about the sources and potential hazards of plastic and other pollutants in the famous alpine lakes on the California-Nevada line.
It also takes organizers on a tour of the history, folklore and development of the lake at the top of the Sierra Nevada, which has enough water to cover all of California 14 inches (36 cm) deep.
Before the westward expansion of the mid-1800s brought railroads, lumber tycoons, and ultimately Gatsby-esque decadence, the Washoe tribe fished for centuries on turquoise-blue Lake Tahoe, becoming a playground for the rich and famous.
Tahoe’s first casino was built in 1902 by Elias J. “Lucky” Baldwin, who owned a large piece of land east of Los Angeles and built the famous Santa Anita Racetrack in 1907. Over the decades, numerous lakeside estates have been built, one of which was used to film “The Godfather Two.”
Cleanup organisers said one of the most frequently asked questions by locals was whether they had found the remains of any gangsters near the North Shore. That’s where Frank Sinatra lost his gaming license for allegedly forming a friendly relationship with an organized crime boss at his Cal-Neva hotel-casino in the 1960s.
The recovered debris mainly includes bottles, tires, fishing gear and sunglasses.
But Colin West, founder of Clean Up the Lake, a nonprofit environmental group that launched the project, said there were some surprises.
Divers thought they found wreck planks near Dead Man’s Point, and tribal lore tells of a Loch Ness-like creature – later known as “Tahoe Tessi” – living under cave rocks.
They also found some “no littering” signs, engine blocks, lamp posts, diamond rings and “those funny fake plastic owls that sit on boats to scare off birds,” West said.
“It’s astounding to see how much trash is piling up under such a pristine lake,” said Matt Levitt, founder and CEO of Tahoe Blue Vodka, which donated $100,000 for the cleanup.
His business is one of many — including hotels, casinos and ski resorts — that depend on annual visits of more than 15 million people to absorb what Mark Twain described in “Roughness” in 1872 as “the best the whole earth has to offer.” beautiful picture”. “
“It’s our economic engine,” Levitt said.
While the primary motivation for most contributors and volunteers is to help beautify the lake, what excites scientists is what happens once the trash comes ashore.
Shoreline cleanups have been carried out across the country over the years, from Arizona to the Great Lakes, Pennsylvania and Florida. But this waste goes into recycling bins and garbage bags for disposal.
Each piece from 189 separate Tahoe dives to a depth of 25 feet (8 meters) is mapped by GPS and carefully divided into categories such as plastic, metal and cloth.
Plastics are key, as international research increasingly shows that certain types can break down into small pieces called microplastics.
Scientists are still studying the extent and harm to humans of these tiny fragments. But the U.S. National Academy of Sciences said in December that the United States, the world’s largest producer of plastic waste, should reduce plastic production because there is so much plastic in oceans and waterways.
Biochemist Zoe Harrold led scientists at the Desert Research Institute at Reno in 2019 to first document microplastics in Tahoe. She is the lead author of the Clean Up the Lake 2021 6-mile (10-kilometer) pilot project report.
“If left in place, the continued degradation of underwater litter, especially plastics and rubber, will continue to slowly release microplastics and leachate into the azure waters of Lake Tahoe,” Harold wrote.
Half a century ago, as the basin began to experience explosive growth, scientists began to measure the waning clarity of Lake Tahoe before the cleanup.
The completion of the interstate system for the 1960 Winter Olympics near Tahoe City was largely credited or blamed. For the first time ever televised, it introduced the world to a lake surrounded by snow-capped peaks.
From 1960 to 1980, Tahoe’s population grew from 10,000 to 50,000 to 90,000 in the summer, according to the USGS. Peak days are now approaching 300,000.
“Most of what we’ve pulled out is basically just the result of the human impact of rebuilding, living and building communities in the Lake Tahoe area,” West said.
His team plans to dive in other Sierra Lakes this year, including June Lake east of Yosemite National Park, and expand future Lake Tahoe searches to greater depths.
The nonprofit Tahoe Fund, which also helped raise $100,000 for the cleanup, is commissioning artists to make sculptures out of Tahoe trash at an event center in Stateline on the southern shore of the lake.
“We hope it inspires more environmental stewardship and reminds those who love Lake Tahoe that we all should take care of it,” said Amy Berry, CEO of the Lake Tahoe Fund.