Russ Zimmer

@RussZimmer

Bacteria borne from fecal matter is rising in the Navesink River, threatening its economic and recreational future, according to a new report by the conservation group Clean Ocean Action.

Several samples taken from the river between 2011 and 2014 at locations near Middletown and Red Bank tested above safe swimming limits for fecal coliform, a bacteria found in the intestines of warm-blooded animals, including humans, the report says.

One sample registered at 12 times the acceptable level for bathers.

The report, one year in the making, comes a few days after the state Department of Environmental Protection announced plans for a comprehensive study to figure out what's causing the river's degradation and how to stop it.

“While the river remains safe for boating, we need to find out why we are seeing increasing levels of bacteria in the water," said DEP commissioner Bob Martin in a news release. "A healthy river is vital to the quality of life, economy and recreational opportunities for the communities that surround the Navesink.”

Eyebrows were raised in January 2015 when the NJDEP suspended, and later prohibited, the harvesting of shellfish from 565.7 acres of the Navesink, west of the Oceanic Bridge. There is currently only one area of the Navesink and Shrewsbury where direct shellfish harvesting is allowed, and that's only from November to April.

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Clean Ocean Action said it doesn't yet know what sources — humans, geese, horses, other animals — are producing what share of the waste.

However, some of the blame for the sorry state of the river can be traced to decades of swapping forests and fields for parking lots and buildings, according to the report. Development has created a sort of highway that carries polluted rainwater straight to the Navesink.

Open space can absorb rain, but asphalt, concrete and rooftops generally do not. That water is funneled into stormwater sewers, which release the water — and whatever pollution it has incorporated along the way — back into the environment.

"Regardless of the type of animal, fecal material is transmitted into waterways through the flow of stormwater over the land," the report reads. "The more impervious surface, the more volume of stormwater there is to mobilize this fecal material."

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Russ Zimmer: 732-557-5748, razimmer@app.com