Every January, they appear on curbs across the country: discarded Christmas trees that signal the end of the holiday season. If you're like most people, the first thought that comes to your mind is almost certainly not, "That tree would make a great home for a fish."
That is, not unless you're a fisheries biologist from Lake Havasu.
In fact, for the last 10 years, a coalition of government agencies and community volunteers have been dumping old Christmas trees and other bundles of brush into Lake Havasu under a scheme to help rebuild once-crashing populations of fish by creating new habitat and food sources.
Lake Havasu, located along the Colorado River at the Arizona-California border, is a man-made vacation gem that came into existence in 1938 with the completion of Parker Dam, about 155 miles downstream of Hoover Dam. The 19,000-acre reservoir is the core of an epic feat of public works engineering that has played a major role in the growth of the Southwest United States. It's the primary source of water for Los Angeles and much of Southern California, as well as parts of Arizona. Parker Dam's four turbines generate hydroelectric power that's used to pump water through the aqueducts, with excess power sold throughout Arizona, California and Nevada.
But none of this matters to fishermen. Fish are what matter to fishermen. And for decades after its formation, Lake Havasu was also one of the nation's premier freshwater sport-fishing spots. It was the site of big-purse tournaments and a beloved vacation destination for non-pro anglers from every corner of the country. The shoreside community of Lake Havasu City thrived, capitalizing on the tourism business.
Then the fish disappeared.
By 1990, populations of Lake Havasu's legendary bass (largemouth, smallmouth and striped), sunfish, catfish, carp, crappie and razorback sucker had all dwindled. When fish anglers still managed to pull up fish, they were half the size of bygone years.
"The reservoir had basically died, and that affected the local economy," said Bill Bryan, a facilities supervisor for the Bureau of Land Management near Lake Havasu City, Arizona.
So what happened to the fish? It turned out the pristine lake was, well, a little too pristine: When Parker Dam was built, the river valley was submerged, along with millions of acres of trees and other plants. These plants served as refuge where small fry could hide from bigger fish, and as they rotted, the fuzz of algae and underwater insects on their branches served as a food source. But after a few decades, the initial supply of plant matter had decomposed, leaving the fish without their food and cover.
To help recover the fishing that was so important to the community, about 20 years ago the BLM and other groups started a program to drop artificial habitats onto the lake floor. Cleverly constructed of PVC tubing of various sizes, or rolled-up plastic snow fencing (to simulate hollow logs), the structures were placed in 43 coves around the lake. With the help of stocking programs, fish counts eventually improved.
Ten years later, the Lake Havasu stewards got the idea to try replenishing the plant matter. And because old Christmas trees are plentiful every winter, they seemed like an ideal choice. The BLM and its partners loaded bundles of Christmas trees and other brush onto boats and placed them around the artificial habitats.
As hoped, the trees and brush provided additional refuge and food for the fish – and their populations bounced back. Every year, said Bryan, they drop 1,200 to 1,300 bundles of brush and trees into the lake, and local lawn and tree maintenance companies are only too happy to drop off the brush at the lake for free rather than pay to dump it at the landfill. Most of the fish populations have recovered substantially since the start of the tree-dumping program.
"The fishing has grown from almost nothing when the project started 20 years ago to the point where now we have a multimillion-dollar fishing tournament in town," said the BLM's Bryan. That means the area gets an influx of people and families paying for food, hotels, fuel, rentals and so on. "It helps the local economy to the tune of millions of dollars."
These days, there's a fishing tournament at Lake Havasu most weekends, said Arnold Vignoni, president of the Lake Havasu chapter of Angler's United, a private organization whose members have played a big role in the fish-recovery efforts. The contests are a pretty clear indicator of fish quality. "Eight or 10 years ago, catching a 13-pounder would get you into the money," said Vignoni. "Now you have to catch at least a 21-pounder or better to have any chance of finishing in the money."
In concert with the brush and habitat program, the BLM also built six fishing piers and docks (with handicapped access) for the non-pros and for folks who don't use, or can't afford, boats. Habitats were placed within catching distance of the piers to improve the fishing at those spots.
"Our goal is to get families out there to enjoy and benefit from the public land," said Bryan.
Lake and reservoir managers and biologists in other areas have kept their eyes on Lake Havasu. Quinn Granfors, an environmental scientist with the California Department of Fish and Wildlife, has introduced brush-dumping programs at two lakes in Riverside County, California. "The brush jumpstarts the ecosystem," Granfors said. "The timing on Christmas trees is excellent because we get them in December and January, and can get them into the water before the fish spawn in spring, so the babies have a habitat to hide in."
But managing fish populations is not as easy as falling off a log, or dropping one into a lake. These are complex ecosystems, and because of differences in behavior the brush and habitat programs help not all animal species equally.
"The species that benefit might not always be the ones that were intended for enhancement, and benefits to unintended species could be to the detriment of desirable species," said David A. Beauchamp, professor of Aquatic & Fishery Sciences at the University of Washington. "So whether the effects of these practices are positive, neutral or negative depends on the objectives for sinking the trees, the fish and crayfish species already present, water level and temperature fluctuations throughout the year, and evidence for what currently limits the desirable species."
Lake Havasu, like waters everywhere, also faces new challenges to its fisheries, such as the threats from invasive and destructive species like the quagga mussel infestation that appeared a few years ago. The BLM introduced redear sunfish, which they hope will eat the quagga mussels, and is also trying to reintroduce long-gone native Colorado River species, such as the razorback sucker and the bonytail chub.
Several government agencies work together to administer the brush program at Lake Havasu, including the BLM, the U.S. Fish and Wildlife Service, and the Bureau of Reclamation (all of which are part of the Department of the Interior), as well as the California Department of Fish and Wildlife and the U.S. Geological Survey. But volunteers, like those in Anglers United, have been an integral part of the program's success.
"I couldn't do this job without their help," said Bryan. "The government puts in some money for our salaries and equipment and boats, but this project only works because of the community. We have help like the waste management people in town who donate hauling and trucks. It's a great community effort."
And apparently those old Christmas trees had one last gift in them.
Paul Karon is a writer based in Los Angeles, CA. His work has appeared in The Los Angeles Times, Variety and Men's Fitness, among other publications. He has also contributed to National Public Radio and has written for television.