Baby Bunker Die-Offs Hit Little Egg Harbor in 85-Degree Waters

Q: What hidden danger is turning Barnegat Bay's dead-end channels into a suffocating trap for thousands of fish this summer?

The hidden danger is oxygen depletion in hot, stagnant backwaters. In Barnegat Bay’s dead-end lagoons and channels, schools of young menhaden, or peanut bunker, are being pushed in by predators such as bluefish, and possibly dolphins or sharks, then trapped where water circulation is poor. Once trapped, the fish face a lethal combination of high summer temperatures and low dissolved oxygen. Warm water holds less oxygen, and in shallow, poorly flushed channels the fish quickly exhaust what is available. Reports from Little Egg Harbor and Osborn Island describe this as a recurring pattern: thousands of bunker become concentrated in these cut-off areas, then suffocate. Local conservation officials and residents say the problem is worsened by restricted tidal flow, sediment buildup and the man-made lagoon layout, which can prevent fish from escaping back to the bay. The result is repeated fish kills, foul odors and broader ecological stress during prolonged heat. In short, it is not a toxin but a heat-driven, low-oxygen trap created by poor circulation in dead-end backwaters.

1 articles · Updated · The SandPaper · Aug 19

Mass fish kills of baby bunker have hit Little Egg Harbor, especially near Osborn Island, with carcasses quickly rotting in persistent summer heat.
Eighty-five-degree surface waters in lagoons and other dead-end bay areas likely drove dissolved oxygen to minimal levels, causing tightly packed menhaden to suffocate within minutes.
Bluefish may be worsening the die-offs by corralling bunker into low-exchange backwaters at night; dolphins and sharks are also cited as a lesser possibility.
Hot weather is forecast to continue, raising the risk of more kills in nearby spots such as Harvey Cedars on Long Beach Island, which has dealt with similar events before.