ALDEN FERRY, Ohio — The Alden Ferry Park District will close the east reservoir dock at 7:30 p.m. this week after visitors gathered there to view a pale band of water that remained bright after the surrounding shore had gone dark. The boat ramp, west fishing pier and all daytime facilities remain open, district superintendent Marla Kess said.
The first report came Friday from two anglers leaving after sunset. They described a strip of water about 70 yards long beyond the dock as having the color of late afternoon. Trees on both sides were dark, and the sky above the reservoir had already turned gray. The band did not cast visible light on the dock or the anglers' equipment.
A ranger observed the same condition Saturday. From shore, ripples within the band showed pale blue and silver while the rest of the surface reflected the night sky. The boundary moved with the water rather than remaining fixed to a reflection from a building or road. It faded at 1:17 a.m., according to the ranger's incident entry.
The reservoir supplies irrigation water to two municipal ball fields and serves as a public fishing lake. Its level, temperature and clarity were within seasonal ranges Monday. Staff found no fuel sheen, floating material or concentration of algae near the east dock. Fish and waterfowl continued moving through the bright area without an observable change in behavior.
Park employees checked nearby houses, the maintenance yard and a telecommunications tower for a light source. None has equipment directed toward the water. Headlights from County Road 4 can briefly reach the shoreline, but the road curves away from the reservoir and could not account for a continuous band lasting several hours.
Some microorganisms emit light when disturbed, said freshwater ecologist Rina Bhatt, who reviewed photographs for the district. That glow is usually green or blue and follows movement in the water. Bhatt said the reservoir photographs instead resemble reflected daylight, though the district has not collected a nighttime sample from within the band.
About 60 people came to the east dock Sunday evening after photographs circulated locally. Rangers asked visitors to keep the access lane clear and treated two minor falls on the sloped bank. Neither person required hospital care. Kess said the temporary evening closure is meant to prevent crowding, not to restrict boating or address a water-quality hazard.
Staff placed a dark maintenance tarp over a ten-foot square of water beside the dock before sunset Sunday. The tarp was held above the surface on a floating frame so it would block the sky without mixing the water. The uncovered band appeared at 7:41 p.m. and remained visible on both sides of the frame.
The district has asked a nearby college to provide a light meter and water sampler for an observation later this week. No chemical treatment is planned. Kess said the park will restore ordinary closing hours when staff can manage the dock without additional crowd control, even if the appearance itself remains unexplained.
Monday's closure sign directs evening anglers to the west pier, where the water has darkened normally. Park employees will continue photographing the east basin from the same marked spot and recording weather, sunset and the time the band fades. Daytime boat permits and youth fishing reservations are not affected.
When employees lifted the tarp at 6:28 Monday morning, the reservoir around it reflected the low gray dawn. Water beneath the covered square showed a clear blue sky with small white clouds. The image broke apart within about 90 seconds and was replaced by the same dawn reflection as the rest of the lake. No clouds were present over Alden Ferry at the time.