It was a shocking discovery along the water front in Oceanport this weekend when thousands of dead fish washed across the shore.

The fish that washed up from the Shrewsbury River are adult menhaden, a species in the herring family and the reason they did so was due to a lack of oxygen.

"This impacted several creeks in the Shrewsbury River estuary," Larry Hajna with the NJ DEP tells WOBM News. "We took some water samples, focusing on dissolved oxygen. We confirmed low dissolved oxygen in a number of samples."

Hajna says predatory fish can sometimes chase large schools of bait fish into estuarine creeks.

"These huge schools of bait fish deplete oxygen in these shallower waters, particularly when the tide recedes, causing large die-offs," Hajna said.

When incidents like what was reported on Saturday occur, local governments will try to remove as many dead fish as they can but, "many (fish) will simply sink, decompose and become part of the estuary’s nutrient cycle."

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