Managing Gulls to Reduce Fecal Coliform Bacteria in a Municipal Drinking Water Source

Abstract

Large numbers of ring-billed gulls, herring gulls, and greater black-backed gulls roost each night on a municipal drinking water source in Maine and have been identified as the primary source of elevated fecal coliform bacteria levels. The lake has a resident gull population of approximately 800, while more than 3,000 gulls have been observed during seasonal migration. To alleviate this public health concern, the U.S. Department of Agriculture APHIS Wildlife Services program implemented an Integrated Wildlife Damage Management program in 2005. The program included the use of pyrotechnics and watercraft to harass gulls, as well as shooting to reinforce and enhance the effectiveness of non-lethal methods. Management activities were effective in keeping gulls off the drinking water source and lowering coliform bacteria levels to within EPA water quality standards. Additionally, the integrated program also involves an ongoing survey in areas surrounding the lake to identify feeding, loafing, and roosting areas that may affect gull movement. Information collected from the survey will result in more effective management practices and contribute to the long-term goal of reducing gull use on the lake.

Egg Oiling to Reduce Hatch-Year Ring-Billed Gull Numbers on Chicago’s Beaches During Swim Season and Water Quality Test Results

“…Defining the beneficial effects on water quality from reducing HY gull beach usage is not straight-forward, because a variety of factors combine to affect bacterial counts at the beaches, such as temperatures, wind/wave/ rainfall patterns, and beach grooming techniques. Nevertheless, there is well-reported documentation that gull fecal contamination degrades water quality (Kinzelman et al 2004;Lake County Board 2004;Levesque et al 2000;Nugent et al 2008;Whitman et al 2004). Historically, the frequency of swim advisories and swim bans in Chicago begins to increase during July.…”

“…Elsewhere, Edge and Hill (2007) showed bird droppings were primary sources of E. coli contamination at a Lake Ontario beach, and Levesque et al (2000) documented that bacterial content of ring-billed gull droppings can contribute to microbiological contamination of recreational waters. Nugent et al (2008) described how ringbilled and other gulls contributed to increased fecal coliform levels in a municipal drinking water source. In Racine, Wisconsin gull feces were found capable of carrying human pathogens (Kinzelman et al 2008) and gulls were a significant non-point source of fecal contamination on beaches (Kinzelman et al 2004).…”

Annual Mortality Limit for Four Gull Species in the Atlantic Flyway

“…When the USFWS permits management of conflict bird species, the permitted actions can be nonlethal (such as hazing or habitat management to deter or exclude) or lethal. Although nonlethal actions are preferred, sometimes lethal take of gulls is necessary for addressing conflicts (Dolbeer et al 1993;Nugent et al 2008). It is the responsibility of the USFWS to ensure that take is within sustainable limits for bird populations and that it does not impact long-term conservation of species.…”

The Chicago Ring-Billed Gull Damage Management Project

“…Edge and Hill (2007) showed that bird droppings served as primary sources of Escherichia coli contamination. Levesque et al (2000) documented that the bacterial content of ringbilled gull droppings can contribute to microbiological contamination of recreational waters, and Nugent et al (2008) described how ring-billed and other gulls contributed to increased fecal coliform levels in a municipal drinking water source. Data collected on or near Chicago beaches indicated that gulls were the source of E. coli in ≥50% of the samples (Whitman et al 2004).…”