Game Fish Numbers Down on the Mon

Washington PA Observer Reporter
18 July 2010

The recovery of Pittsburgh's three rivers has been well documented. But also know that it is certainly not complete.

As we have learned the hard way in the last year with the large fish kill on Dunkard Fork, the precarious tightrope that waterways walk is a small one.

Because of that, since the late 1990s, scientists from West Virginia University's Water Research Institute, University of Pittsburgh, and Carnegie Mellon University have monitored chemistry and water levels in more than 1,200 abandoned underground mines within the Monongahela River basin.

Their findings are somewhat alarming, as they have found that increasing water levels in abandoned mine pools continue to threaten the delicate balance of not only the Monongahela River, but tributaries such as Dunkard and Ten Mile creeks.

As late as the 1960s, the Mon was a nearly dead river. But it currently supports more than 70 species of fish. But, as researchers have found, population levels of those species are constantly changing.

Results of a recent survey of the river suggest the Mon basin is in the early stages of recovery but could easily take a step backward.

Because of that, the Pennsylvania Fish and Boat Commission keeps a very close eye on fish populations and species in the Mon basin.

Even though the basin had been sampled as recently as 2003, another survey was conducted last year, the results of which have finally been made public.

What the commission found was that game fish numbers have suffered a decline in the past decade.

In the 2003 survey, 2,093 fish representing 45 species were sampled at three Monongahela River navigation dams in Pennsylvania. The 2009 survey netted 4,501 fish from 57 species at the same sites. Included in those species was a 9-inch paddlefish collected from the tailwaters of the Maxwell Locks and Dam.

While the 2009 survey found more fish, the species breakdown was far different than the 2003 survey.

Emerald shiners were the most abundant fish in both cases. But while 378 were found in 2003, that number jumped to 856 in 2009.

Sauger (284) and smallmouth bass (278) were the second and third most abundant species in 2003, but were replaced on the 2009 list by two other fish that would be considered forage base for larger species, the mimic shiner (363) and the golden redhorse (310).

In fact, the top four species found in the 2009 survey would be considered forage base for predators, as channel shiners ranked fourth in abundance at 247.

The reason for this shift in sauger and smallmouth bass populations could be higher pollution numbers. Both species are considered pollution intolerant.

The largest number of sauger, walleye and saugeye found in the survey were in the Braddock pool. But the largest walleye found was a 17-incher captured near the confluence of Dunkard Creek.

Braddock also produced the most smallmouth bass with 57 captured ranging from three to 14 inches in length. Grays Landing was a close second in smallmouth, with 53 captured ranging from two to 19 inches in length. A 19-inch smallmouth is an excellent fish.

The abundance of legal walleye, sauger and smallmouth bass were much higher in the 2003 survey with one notable exception. Smallmouth bass at Grays Landing saw their numbers jump considerably.

That's one of the few positives from the 2009 survey, which also turned up just one 22-inch muskie in the entire basin.

Outdoors Editor F. Dale Lolley can be reached at dlolley@observer-reporter.com