It's a brisk morning in mid-December, but it might as well be a low-budget Fourth of July on Lake Adair, as a city of Orlando employee fires off blank cartridges and whistlers at the cormorants that are roosting in the surrounding cypress trees.
Since the migratory cormorants began nesting around the College Park lake more than 20 years ago, city officials claim, they've been one of the main drivers behind Lake Adair's poor water quality.
It's a shitty situation, literally. The cormorants – slender black birds with orange and yellow beaks – eat fish out of the lake and then defecate back into it, and city officials say that's making nutrient levels rise, which can cause algae growth, which can cut off oxygen to the fish population.
Their claim is based on a 1997 study that was produced following the bird brigade's initial landing. It found that the bird dung in Lake Adair was responsible for 1,353 pounds of the lake's phosphorous (73 percent) – the equivalent of two large vending machines – and 2,529 pounds of its nitrogen (36 percent) – the equivalent of an adult walrus.
That's more than Lake Adair's 25 acres can handle, city officials say.
But for some Lake Adair residents and environmentalists, the way the city has attempted to solve the problem is more than they can handle.
On Dec. 3, the city sent a letter to Lake Adair residents saying staff would be "using spotlights, air horns, pyrotechnics and pressurized water to discourage the cormorants from roosting and nesting along the lake." For weeks, a city employee came out twice a day – once in the mid-morning and again in the evening – with flare guns and loud whistler bombs to drive the birds away.
Lake Adair resident Diane Rossi says it's a nuisance.
"I talk to neighbors on the other side of the lake and they say the same thing. They have to leave the house. They can't go outside. It freaks their dogs out," says Rossi, a self-described "birder" who's lived lakeside for roughly four years. "When I first moved here the guy that we bought the house from said, 'I just want to warn you, it's going to sound like a war zone during certain times of the year. Don't be afraid.'"
December was the first time the cormorants have returned since 2015. And with them, officials say, their guano has brought another decrease in Lake Adair's water quality.
Except there's a problem this time around: A March 2018 report on nutrient levels in Lake Adair by the Florida Department of Environmental Protection contradicts the city's water quality assessment. In fact, it doesn't mention the cormorants at all.
"[FDEP] looked at the entire array of nutrients going into the lake and they did not consider in that study the cormorants to be any significant input," says Charles Lee, director of advocacy at Audubon Florida. "The inputs are documented; they grow very specifically and they relate primarily to runoff from lawns and streets. And that is where the bulk of the nutrients coming into the lake are coming from."
In Lee's estimation, there's a 700- to 800-acre watershed area that feeds runoff water into Lake Adair. Some of that water runs onto the streets and the lake's shoreline, and then directly into Lake Adair. Other water is carried from sewer grates throughout the neighboring area and into several larger pipes that transport stormwater into the lake. Lee says that's how lawn fertilizers wind up in Lake Adair.
"It's nutrients," Lee adds. "It's phosphorus and nitrogen, and that's what causes the water quality problems in not just Lake Adair but all of the lakes in the Orlando area."
An environmentalist who asked to be interviewed on background because they are not authorized to speak publicly on the matter offers something similar to Lee's assessment.
This person claims the primary nutrient source for nearly every Orlando-area lake is polluted stormwater inputs.
Lake Adair gets overflow from Spring Lake, the environmentalist says, which is near the Country Club of Orlando's golf course, and it would be very difficult for cormorants to introduce more nitrates and phosphates into Lake Adair than fertilizers and stormwater-related pollutants via the course's neatly manicured greens.
But: "This is one of the few inputs we can actually try to control," says Rick Howard, director of Public Works at the city, of the cormorant dispersal process. Although Howard asserts the cormorants are the main source of Lake Adair's rising nutrient levels, he also says the urbanization of the watershed has created most of the lake's long-term pollution.
"Peoples' fertilizers that run off of lawns and so on are a significant source of nitrogen particularly," Howard says. "We've retrofitted all the [lake's] inlets with filter baskets and we have second-generation baffle boxes" – large structures that filter inputs into water bodies – "that do a lot of nutrient separation. And those are things that we can do and have done, but cormorant dispersal is just another one of those things."
Howard calls it a "best management" practice.
That view doesn't take into account the circular process of the cormorants' diet, Lee says. They dive for their prey (the fish in the lake), eat it, and then what goes in must come out – the cormorants poop into Lake Adair what they took from it in the first place.
While Lee points to the synchronized natural relationship of the cormorants, the fish and the lake, Howard veers the opposite direction.
Howard says a theory like Lee's would only hasten the nutrient loading process. He says Lake Adair's fish population isn't large enough to completely feed the cormorants, so the birds travel elsewhere for their meals sometimes. Then they return, he says, and they bring those nutrients back into this particular water body.
"So yeah, I might agree that if they only fished in Lake Adair it would be kind of a recycling of all those nutrients," Howard says. "But even I could argue against that. I know I'm providing a little circular logic here, but it's worse when they fish elsewhere and bring it back into the Lake Adair system. I don't know if that's clear. I'm not even sure if it's clear." Howard laughs a little.
Lee isn't laughing, though.
"It's a sort of public relations exercise," Lee says. "The city is so far unwilling and unable to tackle the root causes of the problem. So they want to make a show out of shooing the birds in the belief that people think they're doing something about the stormwater because firecrackers and whistlers are going off." He adds: "At best, if there's an issue at all, all they're doing is spreading the issue around."
Maybe Lee's correct. On the mid-December morning when I tagged along to watch a city employee go through the dispersal process routine, only one – maybe two – cormorants were spotted.
The dispersal process, however, continued for several more weeks.
That is, until some Lake Adair residents began to complain, city spokesperson Karyn Barber says.
Although Barber says the city is sticking by its claim of the dispersal method's effectiveness, she says the city has since commissioned an updated study "to examine the water quality in Lake Adair and determine if, or when, to continue the program again next year following the completed study."
"I think it's a waste of time and effort on their behalf," Lee says.