The Pennsylvania Fish and Boat Commission plans to bottom sample the Allegheny and Ohio rivers for rare fish species that may be adversely impacted by sand and gravel dredging, says John Arway, the commission's chief of environmental services.
Although dredging permits issued 10 days ago by the Pennsylvania Department of Environmental Protection require companies to survey for mussels and other species before scooping aggregate from the riverbed, Arway said he and a group biologists will conduct their own bottom sampling in areas earmarked for dredging, before and after it is done.
"We suspect dredging has an impact on fish and we want to know more," said Arway, who will work with biologists from Penn State and California University of Pennsylvania, using state and federal wildlife service funds. They will collect fish by towing special bag-type devices downstream, working in brief, 1/10th the mile drifts, and then emptying fish into tubs for identification.
"We're not sure what we'll find," Arway said, "since this habitat hasn't been studied much at all."
The commission provided DEP with a list of 19 fish -- out of more than 100 species known to be native to the river system -- that dredging companies will have to look for specifically, including longnose sucker, spotted darter, river shiner and silver chub.
"They range from the rarest of the rare to rare," Arway said. "They're fish that existed on the river at one time, and might now."
The discovery of any of the species listed would force the companies either to avoid or alter dredging operations and do further studies in the areas where they are found.
Arway also noted that the impact of dredging on more common species, such as the walleye, which spawn in gravel areas, isn't known.
"It's a question of how much habitat is available for fish to spawn on? Is there a surplus or a deficit? If there's enough, they can move when dredging disrupts their habitat," he said. "If not, they're impacted."
Though dredging has been allowed on the rivers for a century, the discovery of federally endangered Northern Riffleshell and Clubshell mussels near Templeton on the Allegheny 10 years ago raised red flags about the potential impact on habitat. Both Clean Water Action and the fish commission, which has no authority in the permit process, have sought injunctions against dredging in the past, citing mussels and other environmental concerns. Their lawsuits were settled to provide for stricter habitat monitoring and funding for river studies.
In addition to fish and mussel sampling, the new five-year permits issued to Tri-State River Products, Hanson Aggregates PMA Inc., and Glacial Sand & Gravel Co., require that the companies monitor dissolved oxygen levels and to pay for habitat improvements. Though DEP has called the requirements significant, Clean Water Action's Myron Arnowitt said they don't go far enough.
"We've asked DEP to require companies to fill in areas they've dredged with at least a layer of gravel, but that hasn't happened," he said. "We know dredging stirs up toxins from the riverbed, something else DEP hasn't addressed in its permits. The companies can take as much material as they want out of the river. They're creating dead zones, where fish can't survive."
Arway agreed there is evidence that oxygen depletion occurs in areas where dredging makes deep pockets in the riverbed.
"Even if it creates a dead zone for an hour a year, that's enough to suffocate mussels, which can't swim away, but need oxygen like you and me to survive."
The new permits require oxygen monitoring but no sampling for the re-suspension of heavy metals and other toxins because DEP claims past studies show there is no dredging-related impact.
The permits allow for dredging on the Allegheny River from Allegheny to Armstrong counties and on the Ohio in Beaver County. Certain areas, including Templeton, where the rare mussels were found, are still off limits.
The fish commission receives about 30 cents for every ton of gravel dredged from the river, or about $750,000 a year. Under the new permits, an additional nickel on every ton will be earmarked for habitat restoration, including a project planned for Murphy's Bottom on the Allegheny, where an old sand and gravel site will be turned into a 37-acre lake and connected to the main stem of the river.
"It will create backwater habitat for a diversity of species ... although no one is certain how diverse this will end up being," said Rita Coleman, the DEP watershed program manager who helped negotiate the dredging contracts. She said she expects a partnership of state agencies and local universities to develop the project, using funding from the dredging companies to leverage additional support.
As valuable as the development of an off-river embayment will be, said Arway, "it doesn't mitigate damage from dredging."
Dredging companies still await permitting by the US Army Corps of Engineers, which could set forth different requirements, such as more stringent mussel survey protocols. According to Tom Buchele, director of the environmental law clinic at the University of Pittsburgh and the attorney who represented Clean Water Action in its suit against the state, protocols set forth in the DEP permit "protect the dredging companies more than the endangered species."
Buchele said standards for river dredging fall far short of similar operations on dry land, where aggregate also is mined. "The state requires mining companies to reclaim pits even when they're on private land," he said. "With the rivers, we're talking about a public resource, yet nothing like that is required, probably because a riverbed is something you can't see."
He said he would like to see river dredging phased out completely within 10 to 15 years and raises the fundamental issue of whether it is legal for companies to exploit a public waterway for financial gain. "That's a question I've raised since day one," he said.