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Darby, Ridley, West Branch Brandywine & Manatawny creeks
2009 Warmwater Stream Survey results

In August and September, 2009 Pennsylvania Fish and Boat Commission Area 6 personnel sampled four warmwater streams in southeastern Pennsylvania: Darby Creek, Ridley Creek, West Branch Brandywine Creek, and Manatawny Creek. The purpose was to document the warmwater fish communities as part of a greater project that would eventually characterize warmwater stream fish communities throughout the state. Sampling sites measuring 200-386 meters in length were electrofished in the segment of each stream listed in Table 1. Most of the stream segments were characterized by short riffles, long pools, and long glides. The majority of the deepest pools were up to 1.25-1.5 meters deep, but pools were occasionally up to 2.0 meters deep. Stream segments varied from 10-26 meters in width.

Manatawny Creek
Manatawny Creek near Pine Forge

The majority of sportfish captured in the streams consisted of redbreast sunfish, rock bass, and smallmouth bass. Manatawny Creek had the highest electrofishing catch per hour (CPUE) for smallmouth bass with a catch rate of 49 per hour (Figure 1). The West Branch of Brandywine Creek had the highest CPUE of rock bass at 66 per hour (Figure 1). Darby Creek had the highest CPUE for redbreast sunfish at 123 per hour. Legal size smallmouth bass (>=12 inches) were rare, with two having been collected in the West Branch Brandywine Creek, one in Ridley Creek, and none in Darby and Manatawny creeks. The largest smallmouth bass captured was a 14 inch fish from the West Branch Brandywine Creek. Only one rock bass greater than nine inches was collected. That fish was captured in Ridley Creek. No redbreast sunfish eight inches or longer were collected, but Manatawny and Ridley creeks supported the highest densities of 7-7.9 inch redbreast sunfish. Channel catfish were found in the tidal portion of Ridley Creek above MacDade Boulevard and ranged in size from 15-22.5 inches. No walleye were found at any of the sites. Isolated areas of better habitat known to local anglers may have held larger individuals of the above species in any of these streams, but the electrofishing sites were selected to be representative of typical habitat for each stream.

One particular note of interest to some anglers would be the number of trout caught from these warmwater streams. Although the purpose of the survey was to document warmwater fish communities, due to an unusually cool summer, a number of trout survived and were present in these warmwater streams. Manatawny Creek held the most trout with 26 stocked brown, rainbow, and brook trout being caught, along with 46 wild brown trout. The stocked and wild trout measured up to 14 inches in length. Most of the wild brown trout were caught in the upstream half of the survey segment (Table 1). A total of 12 stocked brown and rainbow trout were captured at six survey sites on Darby Creek, while a total of two stocked brown trout were captured from four sites in Ridley Creek. No trout were found in the West Branch of Brandywine Creek.

American eels, which migrate from the Sargasso Sea and utilize rivers and streams as nursery water before returning to the Sargasso Sea to spawn were seen in all of the streams except Manatawny Creek. Their absence in the Manatawny was likely due to the many dams on the Schuylkill River that the eels would have to maneuver through, around, or over to access the stream’s mouth. This situation may improve as two more Schuylkill River dams are slated for removal in fall 2009. These removals will allow the four Schuylkill River fishways located downstream from Manatawny to allow unimpeded fish passage through this reach for the first time since installation of these dams over a century ago. Darby Creek yielded the highest number of eels we observed at one site, with 205 counted. Overall, Darby Creek produced the highest average number of eels per site (117). Ridley Creek had an average of 113 eels counted per site, while in the West Branch Brandywine Creek 11 eels were counted at one site and no eels were counted at the other site.

In addition to the aforementioned species, other fish species captured in these warmwater streams were: bluegill, green sunfish, pumpkinseed, yellow bullhead, brown bullhead, longnose dace, blacknose dace, cutlips minnow, silvery minnow, common shiner, satinfin shiner, spottail shiner, spotfin shiner, swallowtail shiner, golden shiner, white perch, redfin pickerel, white sucker, northern hogsucker, creek chubsucker, tessellated darter, margined madtom, fallfish, banded killifish, largemouth bass, striped bass, creek chub, and mummichog. Striped bass, white perch, silvery minnows, and mummichogs were all found at or near the heads-of-tide in Ridley and Darby creeks.

To compare results from these stream surveys to other southeast PA streams, the results for the first two years (2007, 2008) of warmwater stream sampling appear in Figure 2. Note that the West Branch Brandywine Creek sites sampled in 2009 differed from the sites sampled in 2007, which extended from Buck Run to the mouth.

Table 1. Approximate upper and lower warmwater stream survey limits

Stream Upper Survey Limit Lower Survey Limit Number of sampling sites
Darby Creek Route 3, West Chester Pike Colwyn (upper tidal area) 6
West Branch Brandywine Creek Route 30 Mortonville 2
Ridley Creek Ridley Creek State Park MacDade Boulevard (upper tidal area) 4
Manatawny Creek Spangsville Mouth of Stream 4


Figure 1. 2009 Warmwater Stream Smallmouth Bass and Rock Bass Catch per unit effort (CPUE) per hour

Figure 1

Figure 2. 2007 and 2008 Warmwater Stream Smallmouth Bass and Rock Bass Catch per unit effort (CPUE) per hour

Figure 2

-- Area 6

2007/2008 Warmwater Stream Survey

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