It's an alarming sight to see in New Haven as fish continue to belly-up in the Mill River.
Hundreds and hundreds of Atlantic Menhaden, or Bunker, are schooling by the tide gate, near the Humphrey Street Bridge.
They are suffocating because they're using up all the oxygen in the water. Marine fisheries biologists with the Department Of Energy And Environmental Protection believe hungry adult bluefish have forced the menhaden up river and are blocking their escape back down river.
Although it's disturbing, DEEP said people shouldn't worry that the fish kill is due to contaminated water.
"We didn't see any other dead species, no dead animals, birds, amphibians, or other species of fish, this is just a natural event," David Molnar, a DEEP marine fisheries biologist, said.
DEEP thinks the fish die-off could last several more days.