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Monongahela River
Biological Monitoring Study
Navigation Lockchamber Surveys at Braddock, Maxwell, and Grays Landing Locks and Dams
September 27 – October 1, 2010

This report summarizes the findings of the 2010 navigation lockchamber surveys of the Monongahela River at Braddock, Maxwell, and Grays Landing Locks and Dams (L/D), which is part of Area 8’s continued monitoring program of this river (Click here for the 2009 Biologist Report of nighttime boat electrofishing surveys). Area 8 last conducted lockchamber surveys of the Monongahela River in 2003 (Click here for the 2003 Biologist Report of lock chamber surveys), this report includes a comparison of 2003 and 2010 results.

For over a century, the Monongahela River experienced widespread water quality degradation and ensuing near loss of its fisheries. Combined state and federal efforts that began in the 1970s, however, eventually led to tremendous improvement in the Monongahela’s water quality. Improved water quality resulted in gradual recoveries of sport fisheries, also accompanied by range expansions of numerous native species that were once locally exterminated and overall increases in fish population abundances. The best documentation of the Monongahela River’s recovering fish populations can be found in lockchamber survey findings. Since 1957, 94 lockchamber surveys have been conducted on the Three Rivers, including 36 on the Monongahela River. Notwithstanding these dramatic improvements, water quality problems continue to impact Monongahela River fish populations, primarily from industrial (coal mining and gas well development), municipal (sewage and landfill operations), and non-point sources (agricultural, suburban and urban run-off).

For the 2010 lockchamber surveys of the Monongahela (Figure 1), the Pennsylvania Fish and Boat Commission’s (PFBC) Fisheries Management Division Area 8 and Three Rivers biologists (Figure 2) were assisted by biologists from the West Virginia Division of Natural Resources’ District 1 (WVDNR), Ohio River Valley Water Sanitation Commission (ORSANCO) (Figure 3), U.S. Environmental Protection Agency’s Region III Freshwater Biology Team (USEPA), U.S. Army Corps of Engineers Pittsburgh District (USACE) (Figure 4), Pennsylvania Department of Environmental Protection’s Southwest Regional Office in Pittsburgh and Office of Water Management in Harrisburg (PADEP), California University of Pennsylvania (CalU) (Figure 5), West Virginia University (WVU), Duquesne University, and Marshall University.

Figure 1. Fleet of state and federal agency research boats at a Monongahela River lockchamber survey.
Figure 1
Figure 2. PFBC’s Three Rivers crew (boat in foreground) and Area 8 crew (boat in background) at Braddock.
Figure 2
Figure 3. ORSANCO Biologist John Spaeth (boat operator) and his enthusiastic crew of interns (left-to-right; Emily Heppner, Josh Vogel, Jamie Wisenall, and Danny Cleves) at Braddock.
Figure 3
Figure 4. USACE biologists Bob Hoskin (left), intern Cory Walker (center), and Rose Reilly (right) processing sauger and gizzard shad at Braddock.
Figure 4
Figure 5. (Left-to-right) Matt Kinsey (PFBC Three Rivers fisheries biologist aide), Dr. David G. Argent (CalU Professor of Wildlife and Fisheries Sciences), Alyssa Baxter (PADEP water pollution biologist), Tyler Brown (CalU student), and Dan Dascani (CalU student) separating gizzard shad from shiners at Braddock.
Figure 5

All fish collected during the lockchamber surveys were enumerated and measured for total lengths and weights. A comparison of 2003 and 2010 findings are summarized in the following tables (Table 1 Grays Landing, Table 2 Maxwell, and Table 3 Braddock).

The results also include numbers of “remarkable species” collected. PFBC biologists thought that for a meaningful data interpretation and straightforward measure of biological integrity, fish species inherently more valuable, or “remarkable”, should be considered. Remarkable species, then, regarded appropriate for this evaluation consist of the following:

  1. Nongame fish species either previously (e.g., mooneye, Pennsylvania-Threatened until 2010) or currently (e.g., ghost shiner, Pennsylvania-Endangered) protected in Pennsylvania;
  2. Important sport fish species maintained by natural reproduction (e.g., smallmouth bass, walleye, and sauger); and
  3. Fish species classified by ORSANCO as intolerant of pollution (e.g., smallmouth redhorse; Figure 6).

Remarkable species summarized in Tables 1, 2, and 3 are depicted in red text.

Figure 6. Pollution intolerant smallmouth redhorse collected at Braddock. This species was initially collected at Braddock in 1985, and were found there during every successive lock chamber survey. They have not been collected at Maxwell or Grays Landing.
Figure 6
Table 1. Summary of 2003 and 2010 results of lock chamber surveys at Grays Landing.
Fish Species 09/17/2003 09/29/2010
# Collected # Collected
Black crappie - 4
Black redhorse 1  
Bluegill 42 1,381
Bluntnose minnow 1 423
Brook silverside - 52
Channel catfish 73 465
Channel shiner 118 806
Common carp 10 113
Emerald shiner 12,986 21,336
Flathead catfish 5 28
Freshwater drum 124 393
Ghost shiner 207 401
Gizzard shad 35 24,181
Golden redhorse 2 -
Golden shiner 1 -
Green sunfish - 228
Johnny darter - 4
Largemouth bass - 3
Logperch - 12
Longnose gar - 29
Mimic shiner 146 806
Mooneye 3 3
Pumpkinseed - 25
Quillback 10 -
Rainbow darter 1 -
River carpsucker 6 4
Rock bass 3 28
Sauger 3 11
Silver redhorse - 13
Silver shiner - 401
Skipjack herring 2 -
Smallmouth bass 11 8
Smallmouth buffalo - 9
Spotted bass - 29
Striped bass hybrid - 14
Tiger muskellunge 1 -
Walleye 16 12
White bass 13 36
White crappie 1 4
Yellow bullhead 1 -
Yellow perch 1 18
Total # Collected 13,823 51,280
Total # Species 28 33
# Remarkable Species 9 14
Table 2. Summary of 2003 and 2010 results of lock chamber surveys at Maxwell.
Fish Species 09/16/2003 09/30/2010
# Collected # Collected
Black crappie 1 -
Bluegill 31 372
Bluntnose minnow - 77
Brook silverside 1 98
Channel catfish 80 194
Channel shiner 85 2,907
Common carp 18 32
Emerald shiner 6,099 9,001
Flathead catfish 13 8
Freshwater drum 615 151
Ghost shiner 89 4,354
Gizzard shad 117 10,887
Golden redhorse - 1
Green sunfish 1 15
Logperch - 36
Longnose gar - 3
Mimic shiner 97 580
Mooneye 1 -
Paddlefish 1 -
Pumpkinseed - 14
Quillback - 10
River carpsucker 1 -
Rock bass 1 70
Sand shiner - 294
Sauger 1 4
Silver chub 23 -
Silver redhorse - 3
Silver shiner - 294
Skipjack herring 3 2
Smallmouth bass 3 13
Smallmouth buffalo - 1
Spotfin shiner - 7
Spotted bass - 124
Striped bass hybrid 3 1
Walleye 4 28
White bass 18 106
White perch 1 -
Yellow perch - 3
Yellow bullhead 3 -
Total # Collected 7,310 29,690
Total # Species 26 32
# Remarkable Species 11 12
Table 3. Summary of 2003 and 2010 results of lock chamber surveys at Braddock.
Fish Species 09/15/2003 10/01/2010
# Collected # Collected
Bluegill 5 408
Bluntnose minnow - 1,437
Brook silverside - 6
Channel catfish 68 113
Channel darter - 6
Channel shiner 96 2,507
Common carp 79 6
Emerald shiner 344 4,535
Flathead catfish 21 6
Freshwater drum 181 196
Ghost shiner 81 465
Gizzard shad 60 13,294
Green sunfish - 9
Largemouth bass - 2
Logperch - 11
Longnose gar - 1
Mimic shiner 119 -
Mooneye 1 -
Pumpkinseed - 32
Quillback - 1
Redear sunfish 1 -
River carpsucker 1 -
Rock bass 1 3
Sauger 6 8
Saugeye 1 -
Silver chub - 6
Silver redhorse 1 3
Skipjack herring 1 38
Smallmouth bass 1 3
Smallmouth buffalo 18 3
Smallmouth redhorse 2 3
Spotfin shiner 1 66
Spotted bass - 94
Walleye 9 7
White bass 27 98
White crappie - 2
White perch 2 -
Yellow perch - 1
Total # Collected 1,127 23,370
Total # Species 25 32
# Remarkable Species 11 14

The total number of fish collected, total number of species collected, and number of remarkable species collected were higher in 2010 than 2003 at all three lockchamber locations. These results are encouraging, and are a testament to the improving fish populations of the Monongahela River. Total biomass was also greater in 2010 than 2003 at Grays Landing and Maxwell, but not at Braddock; where in 2010 less carp and smallmouth buffalo were collected than in 2003. These results are even more encouraging when we combine them with our 2003 and 2009 fish assemblage indices (Click here for the 2009 Biologist Report of nighttime boat electrofishing surveys). Those data showed no statistical differences between survey years.

Results that are particularly impressive are the long-term improvement trends (1967-2010) of total species and remarkable species collected at Maxwell (Figure 7) and Braddock (Figure 8). At Maxwell, not a single fish was collected in 1967, and only one bluegill in 1968. In 1975, PFBC began stocking walleye in the Monongahela, and these were first collected at Maxwell in 1978. Naturally reproducing sauger were first collected at Maxwell in 1988, and both walleye and sauger were collected at every successive lockchamber survey since. In 2010, 26,690 fish were collected at Maxwell, represented by 32 species total, and over a third of these species were remarkable.

Figure 7. Lock chamber survey results from 1967 through 2010 at Maxwell depicting positive trends (solid and dashed black lines) for total fish species collected (blue columns) and remarkable fish species collected (red line).
Figure 7

Figure 8. Lock chamber survey results from 1967 through 2010 at Braddock depicting positive trends (solid and dashed black lines) for total fish species collected (blue columns) and remarkable fish species collected (red line).

Figure 8
Another substantial difference between the 2003 and 2010 lockchamber surveys was relative abundance of forage fish (or baitfish). Table 4 (below) compares weights of all forage fish species, including gizzard shad, emerald shiners, mimic shiners, and channel shiners between the two survey years. These results are not that surprising, and reflect how baitfish populations fluctuate year-to-year. Fisheries biologists have found that annual differences in forage fish densities can affect growth rates and recruitment rates of sport fish stocks, including walleye and sauger.
Table 4. Comparison of 2003 and 2010 forage biomass of Monongahela River lockchambers.
Lockchamber 2003 Forage Biomass
(pounds per acre)
2010 Forage Biomass
(pounds per acre)
Grays Landing 10 127
Maxwell 5 46
Braddock 63 162

Biologists from PADEP’s Office of Water Management in Harrisburg collected fish tissue samples from certain sport fish species (e.g., hybrid striped bass, white bass, and channel catfish) for contaminant analysis. These results will be used to update Pennsylvania’s Fish Consumption Advisories, published annually in the Summary Book – Fishing Regulation and Laws provided with purchase of a fishing license. Consumption advisories more restrictive than the statewide advisory of no more than one meal (one-half pound) per week apply to some species from the Monongahela. Fish consumers should consult the summary book for specific details.

PFBC biologists removed otoliths, or ear stones (Figure 9), from certain sport fish species. These calcified structures are one of the most reliable for determining the age of a fish (Figure 10).

Figure 9. Otolith from a 28 inch freshwater drum and a penny for size comparison. Compared to those of other fish species, freshwater drum otoliths are massive. Otoliths collected from large flathead catfish were the size of Lincoln’s head.
Figure 9
Figure 10. Cross-section of the freshwater drum otolith portrayed in Figure 9. Like aging a tree by counting its rings, fish age can be determined by counting the annuli, or annual rings, found inside an otolith. This drum was 28-years-old.
Figure 10
Click for larger image to view ring count

Several factors must be considered when assessing lockchamber fisheries data. As a long-term dataset, they are suitable for depicting overall trends of species richness and composition, but cannot be used to estimate relative abundances of sport fish populations. Also, river conditions during the time of a lockchamber survey can influence catch. With this in mind, of all the lockchamber surveys conducted on the Three Rivers over the past 50 years, the findings at Monongahela River Maxwell L/D exhibit the most striking differences over time.

The findings of the 2010 lockchamber surveys of the Monongahela River have been exceptionally interesting, and several fish species collected during these surveys (e.g., hybrid striped bass and skipjack herring) are not typically collected during nighttime boat electrofishing surveys. The 2010 findings provide further evidence that in a relatively short amount of time (40 years), fish populations of the Monongahela River have rebounded remarkably. Many federal and state agency biologists qualify the Monongahela River recovery as ongoing, and remain concerned about existing and potential threats. Acute water quality degradation from potential catastrophic releases of abandoned mine pools, pollutant loadings from Marcellus Shale natural gas drilling activities, and other impacts could very easily tip the scales and reverse the ongoing recovery process of the Monongahela’s fisheries. Those fisheries, a renewable natural resource, have demonstrated high economic value by attracting international and national sport fishing competitions. Preserving the recovery made thus far and continued work to minimize/eliminate existing threats has potential to transform this river valley into an area containing some of the best sport fishing opportunities in the state.

In 2011, the Monongahela River Biological Monitoring Study will continue, as biologists from PFBC and CalU plan to conduct nighttime boat electrofishing surveys at the same locations surveyed in 2003 and 2009.

— Prepared by Three Rivers Fisheries Biologist Bob Ventorini

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