06/26/2002 Env Bd Packet - Laserfiche WebLink

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continued from p.3 zens see in their backyards in Anoka and Washington counties are most likely nest- ing in this one colony," notes Galli. In other words, the area's herons have all their eggs in one basket: Lake Peltier island, a 30 -acre oasis in a community that is rapidly shifting from agriculture to sub- urban housing development. Owned by Anoka County Parks, the island preserve is home to much more than the heron rookery. Forested with ash, bass- wood, elm, maple, and hickory, it provides habitat for deer and foxes as well as numerous birds —great egrets, wood thrush and veery, red -eyed and yellow - throated vireos, and scarlet tanagers, to name a few. The shoreline and shallows north of the island serve as a spawning area for Northern pike and walleye and as a resting area for terns, black crown night herons, and other waterfowl. The north arm of the lake, says Galli, is one of the few remaining places in the metro area with healthy native vegetation, including water willow, which is considered a species of special concern. Ringed by swiftly growing suburbs, the once- secluded lake now faces increasing pressures from nearby residential develop- ment and recreational use. "This is an area with lots of lakes, wet- lands, and wildlife," says Marty Asleson, environmental coordinator for the city of Lino Lakes. "Folks who are moving in want to preserve it, and that's tough .to do. Sustainability requires a balance between cultural and environmental issues." The heron colony is widely considered one of the county's most outstanding natu- ral features. In fact, the city of Lino Lakes adopted the great blue heron as its logo and even named an elementary school after the birds. Since the colony's abandonment last summer, local residents, city and county officials, and wildlife experts have worked diligently to solve the mystery of the birds' disappearance. With the help of Bell Museum director Scott Lanyon, an ornithologist and resi- dent of Lino Lakes, 10 potential causes of the birds' abandonment were identified in January 2002. Upon further examination, nine of these factors were ruled out, lead- ing a local task force to focus on the most likely possibility: disturbance caused by human activity near the rookery. A heated debate emerged over the Today, the Lake Peltier heron rookery is one of only nine in the seven - county metropolitan area and is the second largest. Great egrets also nest at Lake Peltier. potential impact of a slalom waterski course that had been installed by local resi- dents in the shallow waters along the north side of the island. Though no one can prove that water - skiing is the direct cause of the colony's abandonment, many believe that the extreme disruption and repetitive nature of slalom waterski racing could have been sufficient to drive the birds from their • nests. "We received many comments from residents about high speed boat traffic so that was one of our primary considera- tions," says Perry. Great blue herons are wary, skittish birds. Studies show that, like many birds that nest in colonies, they are particularly vulnerable to human disturbance and rec- ommend a protected "buffer zone" of 250- 500 meters around nesting areas. Though enacting changes meant a complex collaboration across two jurisdic- tions, the city councils of Lino Lakes and Centerville moved quickly to protect the birds. The councils voted to relocate waterskiers to the southern portion of the lake. To protect the rookery and the sensi- tive ecological zone on the north end of the lake, they passed joint ordinances cre- ating a no -wake zone starting approxi- mately 250 feet south of the island. The north end remains open to fishing, canoe- ing, and slow -speed boating. It is hoped that this new buffer zone will protect the rookery from disruption and allow the herons to complete their nesting season. The new ordinances will take effect this summer and will remain in place through 2004. Although some residents opposed the no -wake zone, Galli says it was a neces- sary measure. "We don't think we can wait any longer," she says. "We need to take action now if there's anything we can do that might have meaningful conse- quences." In addition, DNR and park staff mem- bers are working to minimize other traffic in and around Lake Peltier, including sea planes, mosquito control helicopters, and firefighting planes that collect water from the lake. The successful coordination among the several jurisdictions responsible for Lake Peltier —and the swift action of two neigh- boring city councils —may serve as a model for the many other suburbs attempting to conserve natural areas in the face of increasing human activity. As more and more people want to liv closer to nature, many communities are forced to address the impact of increased residential development on their lakes, wetlands, and woodlands. The conflict between boats and birds in Lake Peltier is a classic example of a cultural and envi- ronmental clash, says Marty Asleson, who believes that the new ordinances will be an effective compromise. In March of this year, Art Hawkins returned for a third season to the shores of Lake Peltier, toting a spotting scope and notebook and hoping to see the first arrivals in the herons' spring migration. As cormorants stood guard on the bog poles nearby, Hawkins has watched as great blue herons have once again flown back and forth across the water, fetching sticks for the nests they have abandoned for the pre- vious two years. Now it is the beginning of May and so far, says Hawkins, everything seems to be going well. ■ To find out whether the new ordinances succeed in helping the Lake Peltier heron complete their nesting season, look for a >. update in the fall issue of IMPRINT.