Pennsylvania Fish & Boat Commission Biologist Report
Lake Marburg
York County
2015 Walleye Survey
The Pennsylvania Fish and Boat Commission (PFBC) evaluated the Walleye population
in Lake Marburg on April 14, 2015. The PFBC manages Walleye populations in many
lakes and rivers across the Commonwealth. In southeastern Pennsylvania lakes,
Walleye have limited natural reproduction and are dependent upon hatchery stockings of
two to three inch fingerlings to provide desirable recreational fisheries. The goal of the
2015 electrofishing survey was to examine the relative abundance and size structure of
the Walleye population in Lake Marburg to determine if statewide objectives were met.
Objectives were established in the PFBC’s Walleye Fisheries Management Plan, and
meeting abundance measures, are a requirement to qualify for continued fingerling
stocking.
Lake Marburg is a 1,275 acre impoundment located in Codorus State Park, southern
York County. The park is managed by the Pennsylvania Department of Conservation
and Natural Resources (DCNR) and is located three miles east of Hanover,
Pennsylvania.
Pennsylvania Fish & Boat Commission Biologist Report
Aerial photo of Lake Marburg, York County. Photo courtesy of Kathryn Krueger.
The PFBC began stocking Lake Marburg with Walleye in 1976. The initial stocking
included 5.1 million fry and was followed by fingerling stockings in 1981 and 1983 in an
attempt to bolster the population. From 1984 to 1996, no stockings occurred and the
Walleye population was managed through natural reproduction. In the mid to late
1990’s, natural reproduction declined and became insufficient to support the fishery;
therefore, fingerling stocking resumed. The timing of the decline in reproductive success
corresponded with the development of a robust bass population in the lake due to the
implementation of the Big Bass Program special regulations. Large black bass
populations are known to limit Walleye populations in Pennsylvania and elsewhere.
Additionally, the decline could have been later influenced by angler introduction(s) of
White Perch, which are prolific and are known to substantially negatively impact
desirable sportfish populations when White Perch populations are large. Introduction of
White Perch occurred soon after the Big Bass Program special regulations were
implemented. The PFBC has stocked over 317,000 Walleye fingerlings in Lake Marburg
Pennsylvania Fish & Boat Commission Biologist Report
since stocking resumed in 1997, including 25,500 in 2014 and 38,250 in 2013. Please
visit the PFBC’s website for additional stocking information on warmwater/coolwater fish
species in Lake Marburg, such as Muskellunge, Tiger Muskellunge, and White Crappie.
Nighttime boat electrofishing was conducted along three historically sampled shoreline
sites, including the dam breast, the southeastern shoreline between the dam breast and
Round Island, Round Island, and Long Island. All Walleye captured were measured for
total length and released.
The 2015 Walleye electrofishing catch rate at Lake Marburg was one of the highest
recorded for a southeastern Pennsylvania lake. A total of 78 legal size Walleye, ranging
in length from 15 to 26 inches, were captured (See Figure 1). No sub-legal Walleye
were captured, but this was typical of electrofishing during the spawning period. The
total catch rate of Walleye was 53.5 fish/hr. This catch rate exceeded the early spring,
statewide objective of 18.0 fish/hr established for legal size Walleye in large reservoirs
(>500 acres) and the regional average of 20.4 fish/hr for legal size Walleye in
southeastern Pennsylvania lakes.
Many of the Walleye captured were in thin condition indicating a possible
overabundance of the species. Due to the apparent overabundance and poor condition
of the Walleye in Lake Marburg, the 2015 fingerling stocking was cancelled.
Additionally, the unusually high stocking rates designed to overcome predation, and
previously only applied during alternate years, will be reduced in the future to more
typical statewide annual stocking rates.
Several of the Walleye captured during the electrofishing survey had what appeared to
be Lymphocystis. Lymphocystis is a virus that infects the skin of fish, but is not
associated with Walleye mortality and is harmless to humans. For additional information
concerning such growths on Walleye please see the Question and Answer portion of the
PFBC’s website.
Pennsylvania Fish & Boat Commission Biologist Report
Five other fish species were observed during the electrofishing survey, including Tiger
Muskellunge, Largemouth Bass, Rock Bass, Bluegill, and Common Carp. The Tiger
Muskellunge was approximately 36 inches and was captured along Round Island.
Figure 1. Length frequency distribution of Walleye captured while electrofishing
Lake Marburg on April 14, 2015.
If you plan on fishing Lake Marburg, please be advised that the lake has a 20
horsepower outboard motor restriction and bass are managed under the Big Bass
Program Special Regulations. Lake Marburg has seven boat launches and plentiful
access points for shore anglers. Please visit DCNR’s website for the full range of
recreational activities offered at Codorus State Park.
Greg Murphy
Fisheries Biologist
Area 6 - Southeastern Pennsylvania