By Jessica Bagley
The Tonawanda News
Tonawanda News — The state Department of Environmental Conservation has reported that large numbers of dead and dying fish have been seen in Lake Erie, the Buffalo Harbor, Niagara River and Lake Ontario.
Dead fish are also being observed along the Pennsylvania and Ontario shorelines, the DEC said.
The release from the agency comes after the mayor’s office in the City of Tonawanda received numerous calls from residents who had seen fish floating in the river nearby.
DEC Aquatic Biologists investigated the incidents and discovered that nearly all the dead and dying fish are gizzard shad, a medium-sized member of the herring family. Gizzard shad have a gray color and serve as food for large bass.
The DEC said that because the death of the fish is so widespread and the phenomenon is only affecting one species, pollution is likely not causing the deaths. With only one species being affected, the cause is likely a result of disease, parasite or species-specific stressor. In this case, it is likely a result of cold weather.
“Mortality of gizzard shad in late winter and early spring is common and occurs cyclically, although it usually affects lower numbers of shad locally,” Regional Fisheries Manager Mike Clancy said. “This species is very sensitive to cold water temperatures and their inability to acclimate causes mortality at low temperatures.”
According to the DEC, the Buffalo area waters are the coldest in which the gizzard shad can survive, and so the local shad are especially susceptible to cold temperatures.
In fall 2012, a survey found the highest number of shad in Lake Erie in the last seven years. Recent mild winters may have allowed the species’ population to increase, the DEC said.
The DEC has collected and submitted a sample of gizzard shad to Cornell University’s pathology laboratory for disease screening.
Additional information, including a photograph of a gizzard shad, is available on the DEC website. Contact reporter Jessica Bagley at 693-1000, ext. 4150