Pigeon droppings at the Pismo Beach Pier are responsible for a large share of the water-quality problems in the immediate ocean and nearby beach, a three-year study has found.
The question now is whether to do something about the more than 450 pigeons counted in the area, with nearly 220 nests nestled into the pier itself.
The final report, produced by Cal Poly’s Environmental Biotechnology Institute, recommends capturing and removing the flock, netting the underside of the pier to make it inaccessible to roosting birds, feeding birth control-laced food to the birds so they dwindle in number over time — or some combination of the three.
Researchers said the high counts of pigeon droppings near the pier, the number of E. coli strains that match bird fecal sources, and a survey of the large number of pigeons counted at the pier suggest the birds to be the main source of the high bacteria levels in the surrounding water.
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The Pismo Beach City Council on Tuesday will hear a presentation of the report, but it is not expected to take action.
Several people attending a workshop on the report Wednesday urged city leaders to treat the pigeons humanely.
In 2007, council members voted to hire a pest control firm to trap and kill the pigeons, but they changed their decision after protests from the public and the national animal rights organization People for the Ethical Treatment of Animals. They instead began negotiating with a group to relocate the birds, but that effort fell through when both parties couldn’t agree on a proposal.
“My concern is that the pigeons are being targeted maybe because of a cultural bias rather than a true risk,” San Luis Obispo resident Brooke Foster said. “It needs to be a true risk.”
Two volunteers for the local chapter of the Surfrider Foundation said they’d like to see the city turn the report’s recommendations into action as soon as possible.
The report was authorized several years ago as a joint project between the city and Cal Poly after the county’s Public Health Department noted increases in warnings for high bacteria levels at Pismo Beach.
In October, the Los Angeles-based group Heal the Bay gave the ocean at the Pismo Beach pier a “D” grade in its annual End of Summer Beach Report Card.
The study’s estimated $559,208 cost was mainly covered with state funds through Proposition 50, the Water Security, Clean Drinking Water, Coastal and Beach Protection Act of 2002. Pismo Beach also contributed $98,795.
Data and weekly water sampling were collected though most of 2008, though some year-round collection and testing after rainy weather continued into May 2009, said Chris Kitts, head of the biological sciences department at Cal Poly.
More than two dozen students worked on the overall project, said Kitts, who led the study.
They tested numerous sites, including three extending up Pismo Creek, 10 spots along the beach on either side of the pier — from 600 meters south of the pier to 300 meters north of it — and five ocean sites off Pismo Beach, including one site over the wastewater outfall, located south of the city.
A part of the study provided the only direct evidence of the effect of bird droppings on the area’s high bacteria levels. By collecting strains of E. coli, the researchers traced 40 percent of the strains to bird feces.
E. coli strains linked to pigeon droppings were collected 12 times from within 150 meters of the pier. Researchers also found 47 strains with a seagull-specific fingerprint.
“It’s more of a preponderance of the data rather than a direct smoking gun,” Kitts said. The data point to birds as the main source of the problem, but “it’s other data such as observations and droppings and the location that all point to the pigeons,” he said.
In addition, 20 percent of the E. coli collected matched a canine source — but researchers found no evidence that dog waste had influenced the high bacteria levels.
Also, most of the beach samples over a five-day period spanning the July 4 holiday weekend in 2008 tested positive for human-specific bacteria — though, like the dog waste, it did not influence the specific bacteria that lowers the water quality.
“I think controlling the dogs would help a good deal,” said Johanna Andris of San Luis Obispo, who also urged that the pigeons be treated humanely.
Pismo Beach City Councilwoman Shelly Higginbotham, who attended Wednesday’s workshop, said Mutt Mitt containers are stationed at all beach entrances, which allow people to pick up after their dogs. Dogs are not allowed on the pier.
The city in 2007 adopted an ordinance prohibiting people from feeding the birds and has attempted to cover all trash cans in and around the pier, she said.
Santa Monica officials have recently confronted a similar scenario and hired a company to install netting under their pier.
The state Coastal Commission required a permit for Santa Monica to install the netting and allowed the city to do so as long as there was no adverse impact to birds nesting under the pier at the time the netting was installed, said Al Padilla, a coastal program analyst with the commission’s South Coast District Office.
Reach Cynthia Lambert at 781-7929. Stay updated by following @SouthCountyBeat on Twitter.