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Delaware River Fisheries Bounce Back

For Immediate Release

August 27, 1998

(WEST TRENTON, N.J.) -- Fish populations in the lower Delaware River and Bay have shown a sharp increase in recent years, due in large part to a significant improvement in overall water quality.

These findings are contained in a report prepared by the Delaware River Basin Commission (DRBC) in cooperation with the Delaware Estuary Program, a project set up in 1988 to protect estuarine systems of national significance.

Fisheries on the rebound include American shad, weakfish, striped bass, Atlantic croaker, Atlantic silversides, bay anchovy, black drum, hogchoker, northern kingfish and American eel, according to the report, released in August.

Within the past decade, the striped bass fishery has shown a remarkable recovery and the number of weakfish, the bay's most economically important fishery, is also on the rise, the report notes. Both fisheries pump millions of dollars into local cash registers.

On the downside, Atlantic sturgeon populations appear to be on the decline, as do the number of horseshoe crabs in Delaware Bay. Blue crab populations increased during the 1990s, but sampling surveys indicate their numbers have tapered off in the past two years, the report states.

The improved water quality that brought the fish back is tied to sharp increases in dissolved oxygen in the river. Oxygen levels today range from a minimum of 3.5 milligrams per liter (mg/l) to greater than 12 mg/l at Delaware River and Bay monitoring stations, meeting or exceeding on a yearly average the required minimum DRBC and federal standards.

In the meantime, bacterial levels have dropped off with mean levels of fecal coliform averaging consistently below the federal standards for primary contact recreation in the tidal river and bay. Sampling indicates enterococcus levels likewise are in compliance with these standards.

While water quality in the Delaware has shown remarkable improvement since the days when the lower river was little more than an open sewer, there are still problems that need remedies. The presence of toxics in the river is one of them.

In 1989 fish consumption advisories were issued for striped bass, white perch, and catfish by the states of New Jersey and Pennsylvania, and later Delaware, because of the presence of polychlorinated biphenyls (PCBs) and chlorinated pesticides in tissue samples. The advisories were prompted by studies conducted by DRBC and state agencies.

Other DRBC studies documented that in addition to PCBs and chlorinated pesticides, there are other elevated levels of toxics in the river. These include polynuclear aromatic hydrocarbons (PAHs), and heavy metals such as chromium, copper, lead, mercury and zinc.

The highest concentration of these toxic pollutants occur in a 14-mile, heavily urbanized portion of the river between the old Philadelphia Navy Yard upstream to the Tacony-Palmyra Bridge. Sources include natural phenomena, discharges from industrial and municipal wastewater treatment plants, non-point sources such as storm water runoff, and atmospheric inputs.

As a result of the studies, the DRBC now has on the books regulations governing the discharge of toxic pollutants from wastewater treatment plants to the tidal Delaware River.

The regulations, which took effect Jan. 1, 1997, set uniform water quality criteria for the pollutants for the 85-mile reach of the river from the head of tide at Trenton, N.J., downstream to the Delaware Bay, including tidal portions of tributary streams. They also establish procedures for setting wasteload allocations and effluent limitations where required for 78 riverbank treatment plants.

The water quality criteria are designed to address the effects of acute and chronic toxicity to aquatic life, and the potential for harmful effects on humans through ingestion of untreated river water and/or the consumption of resident fish and shellfish. The wasteload allocation program limits the amount of pollutants that can be discharged by individual treatment plants to achieve the criteria.

Numerous toxic substances, some carcinogenic, are covered under the rules. They include chlordane, PCBs, metals such as lead and mercury, DDT, and volatile organic chemicals.

The regulations were crafted in response to 1987 amendments to the federal Clean Water Act which required states to adopt water quality criteria for toxic pollutants and identify those stretches of waterways where the criteria were being exceeded.

In an effort to meet the federal mandate, Delaware, Pennsylvania, and New Jersey independently developed criteria for the tidal reach of the Delaware, which serves as the states' common border.

Problems inherent in this splintered approach soon became apparent and in 1989, at the request of the three states, the Commission established the Delaware Estuary Toxics Management Program which drafted the new regulations.

They were developed with scientific and policy input from the Commission's Water Quality Advisory Committee, which includes representatives from the state environmental agencies in Delaware, New Jersey, Pennsylvania and New York; the U.S. Environmental Protection Agency (Regions II and III); and representatives from the University of Rhode Island and the Academy of Natural Sciences in Philadelphia.

A second group, the Commission's Toxics Advisory Committee, which was formed in 1995, also provided input. This committee is charged with developing recommendations for the management of toxic substances found in waters throughout the entire Delaware River Basin.

The Commission's toxics management program at first focused only on toxic pollutants found in point source (end of pipe) discharges to the river from both industrial and municipal wastewater treatment plants.

The Commission embarked on the next phase of the program in 1996: to identify and control non-point sources of PCBs and chlorinated pesticides. A study of the loadings of PCBs from ten Delaware River tributaries (plus six additional point sources) was initiated. Commission staff also is identifying other suspected non-point sources, including Superfund sites and landfills.

The Delaware River Basin Commission is an federal/interstate agency responsible for managing the water resources within the 13,539 square-mile watershed. Its members are the governors of the four basin states and traditionally the U.S. Secretary of the Interior.