Mentor City Council and administration invited professionals from the Cleveland Museum of Natural History, Lake Metroparks and Cleveland Metroparks to their Tuesday.
Representatives from each organization agreed deer were a problem, both in Mentor and the region.
"We have 39 nature preserves," said James Bissell, the coordinator of natural areas for the CMNH. " is one of 39. All together the museum has 5,200 acre and we have deer problems everywhere."
Bissell said the deer ravaged the marsh's unique undergrowth. Then local animals -- who would otherwise live in the swamp forest like wood thrushes, oven birds, hooded warblers and more -- no longer had a place to live. Additionally, it left a vacuum that invasive, deer-resistant species filled, he said.
"Quite frankly, this city's in a disaster mode at this point and I really hope something can be done," Bissell said. "We lost a few species that won't come back. The deer wiped them out.
"With that many deer, you're just wiping out your biodiversity -- your plants and the animals that depend on these plants."
Cleveland Metroparks has deer culling programs for eight of its 13 parks, said Rick Tyler, the former senior area manager for the parks system.
Tyler said when he first took his job in the 1970s, he couldn't throw a softball more than three feet in the Bedford Reservation because it would hit something in the underbrush.
But now, because of deer foraging, he said that same softball could go for a 1,000 feet without hitting a shrub.
John Grantham, the chief of park operations for Lake Metroparks, said averages 150 deer per square mile with .
However, in 2010, the park averaged 207 deer per square mile.
Bissell said that deer populations have reached these levels because their natural predators like mountain lions and wolves are all gone from the region.
"The main predator of deer right now is the automobile," Bissell said.
Bissell recommended a culling program to return the deer population to natural levels.
Also from the work session Tuesday: