Ichthyofauna of the Monongahela River Basin in Pennsylvania: A Contemporary Evaluation

Abstract

By the 1900s, the ichthyofauna of Pemsylvania's Monongahela River basin was decimated by a combination of discharges h m industrial, coal extraction, and municipal sources. Over the past half-century, water quality improvements resulting fiom federal and state mandates have initiated a continuing recovery of fish populations throughout the mainstem. We compiled the results of recent collections from the river and its tributary network by a number of state, federal, and academic agencies employing a variety of gear. The combined sampling methods yielded 32,999 fishes on the mainstem, representing 14 families and 64 speciedhybrids, while 6,825 fishes representing 10 families and 5 1 specieshybrids were captured h r n the tributaries. Tributary species richness ranged firom 24 to 0 concomitant with declining water quality. Members ofthe families Ictaluridae and Cyprinidae dominated mainstream communities, while the Percidae and Cyprinidae were prevalent in its tributaries. Twenty-two species were captured only fiom the Monongahela mainstem, while 1 1 were unique to its tributaries and 39 were cosmopolitan. Overall, the Monongahela Basin ichthyofaunal complement currently numbers 75 specieshybrids.

Typical Channel Fish Assemblage of the Recovering Lower Allegheny River Navigation System, Pennsylvania, USA

“…A Shannon community index was computed for the Pool 4 and tributary mouth data to confirm the apparent diversity suggested by the high species richness; the computed value was 3.10, indicating a diverse fish community. Numerically, common carp was reduced to only 0.4% of the total Allegheny River sample, and brown bullhead was totally absent; likewise, Argent et al (2007) did not report a single brown bullhead from the Monongahela River. Species of fish associated with North American great river assemblages and once extirpated from the waters of Pennsylvania were well represented in the lower Allegheny River, as were some species which until recently were considered to be threatened, endangered, or candidate species in Pennsylvania.…”

“…a R designates a species that was either formerly extirpated from waters of the Ohio River drainage in Pennsylvania or is or was until recently listed as a threatened, endangered, or a candidate species in bPe~sylvania, or is an unlisted colonizer or re-colonizer. Not collected from the lower Allegheny River in 200712008 but recently reported from the nearby Monongahela River by Argent et al (2007). Numerically, the Allegheny River fish assemblage was dominated by channel catfish (1 7.0%), channel darter (1 2.9%), and johnny darter (Etheostoma nigrum), freshwater drum, and logperch (Percina caprodes), 10.0%, 7.7%, and 6.9%, respectively.…”

“…However, we did not find a single specimen of any of these four species along the navigation channel reaches of the Allegheny River sampled in 2007-2008. Argent et al (2007) compiled contemporary results of various 2003-2006 fish collections from the nearby Monongahela River navigation system in Pennsylvania and its tributaries by a number of state, federal, and academic agencies. For a variety of reasons, including the close physical proximity and connectivity of the Allegheny River and Monongahela River, habitat similarities as a consequence of alterations to promote commercial navigation, and differences and similarities in sampling gears used, the Argent et al (2007) study invites comparison with our characterizations of the fish assemblage of the Allegheny River navigation system.…”

“…Argent et al (2007) compiled contemporary results of various 2003-2006 fish collections from the nearby Monongahela River navigation system in Pennsylvania and its tributaries by a number of state, federal, and academic agencies. For a variety of reasons, including the close physical proximity and connectivity of the Allegheny River and Monongahela River, habitat similarities as a consequence of alterations to promote commercial navigation, and differences and similarities in sampling gears used, the Argent et al (2007) study invites comparison with our characterizations of the fish assemblage of the Allegheny River navigation system. Six different sampling gearslmethods were used to evaluate the Monongahela Rivertailwater night boat electrofishing, benthic trawling, pulsed DC backpack electrofishing at wadeable tributary mouths, boat electrofishing at non-wadeable tributary mouth reaches, multi-mesh gill nets for large-bodied ichthyofauna, and piscicide rotenone lock chamber sampling (total sample size 39,824 fish).…”

Community concordance between fishes and benthic macroinvertebrates among adventitious and ordinate tributaries of a major river system

“…Adventitious streams have 2004) by isolating populations through the elimination of connectivity corridors. Dam construction, channelization, and pollution as well as the purposeful or accidental introduction of exotic species have markedly altered historical distribution patterns (Argent et al, 2007). Argent and Kimmel (2009) analyzed patterns of fish community connectivity exhibited by tributaries to the Monongahela River (MR) in Pennsylvania.…”