- Jason E. Detar and David Kristine
Status of Fish Populations
The following article has been condensed from the publication “The Fishery of Spring Creek – A Watershed Under Siege” by Robert F. Carline, Rebecca L. Dunlap, Jason E. Detar, and Bruce A. Hollender.
Figures 1 and 2. (Left) Average-size wild brown trout from Spring Creek. (Right) Large wild brown trout. Few individuals reach this size in Spring Creek.
Historically, native brook trout sustained the fishery, which was apparently good enough to attract the famous angler, Theodore Gordon, who raved about the excellent brook trout fishing near Bellefonte Borough in the early 1870s. In a 1915 letter, Gordon writes about a subsequent fishing trip to Bellefonte and notes that brown trout had “taken possession” of the stream. The Corry State Fish Hatchery shipped six cans of brown trout fry to five railroad stations in the watershed between 1892 and 1898. Providing that these fish were stocked in Spring Creek and its tributaries, these stockings may have been responsible for the initial colonization of the stream by brown trout. Brown trout became well-established in the early 1900s and, by the 1940s, had become the dominant salmonid in the watershed. Brook trout continue to persist in Galbraith Gap Run; two tributaries to Slab Cabin Run - an unnamed stream flowing through Musser Gap; Roaring Run; Gap Run; and Logan Branch. Clearly, the native brook trout occupies but a small proportion of its former range within the watershed.
Extensive surveys of the Spring Creek main stem provide a good overview of the fish species composition. During these surveys, 32 species were collected but most of these species have not sustained reproducing populations (Table 1). Eleven species and one hybrid were collected only on one or two occasions: American eel, northern pike, hybrid muskellunge, central stoneroller, goldfish, rosyface shiner, brown bullhead, redbreast sunfish, pumpkinseed, smallmouth bass, black crappie, and yellow perch. The American eel, central stoneroller, smallmouth bass, black crappie, and yellow perch probably moved into Spring Creek from Bald Eagle Creek, while the other species were introduced or escaped from culture facilities. Six species are common throughout the main stem of Spring Creek: cutlips minnow, blacknose dace, longnose dace, white sucker, tessellated darter, and slimy sculpin. Past work on Spring Creek provide convincing evidence that brown trout, though they are usually the focus of fisheries studies, do not represent the largest portion of the fish community biomass. In some reaches, it is likely that white suckers will comprise the largest portion of the fish biomass, and slimy sculpins will be the most numerous species.
Table 1. List of common and scientific names of fishes captured in the Spring Creek watershed, 1958-2008. Collections were made by R. F. Carline, E. L. Cooper, J. E. Detar, and B. A. Hollender.
Reproductive success of brown trout throughout Spring Creek varies greatly among sections and years on the basis of numbers of age-0 fish captured during their first summer, with up to a 20-fold variation among years at sample sites. Spatial and temporal variations in density of age-1 and older brown trout were similar to those for age-0 fish. Across sections, median density ranges from 301 to 1,172/ha (122-474/acre). Data for age-1 and older brown trout from Sections 4, 13, and 15 illustrate typical size structures in the upper, middle, and lower reaches of Spring Creek from Oak Hall to Milesburg. Since 1982, these sections have had the same no-harvest and no-lure restriction regulation. Unlike brown trout density, size structure at these three sections did not vary greatly among years (Figure 3). In Section 4 (mean width = 10.6 m; 0.7 m3/s (25 cfs)), the largest proportion of fish was usually in the 200- to 250-mm (7.9-9.8 inches) length interval. In Section 13 (mean width = 19.5 m; 1.7 m3/s (60 cfs)) and in Section 15 (mean width = 14.5 m; 4.3 m3/s (152 cfs)), the largest proportion of fish was in the 250- to 299-mm (9.8-11.8 inches)length interval. Typically, numbers of brown trout >350 mm (13.8 inches) long were relatively small. In Sections 4 and 13, fish >350 mm long accounted for 2.4% of all age-1 and older trout, and in Section 15 they accounted for 4.4 % across all four census years.
Figure 3. Brown Trout size structure > 150mm in three sections of Spring Creek.Section 4 extends for 1.3 miles upstream of the W. Branch Rd. bridge in Lemont, Section 13 extends for 1.6 miles from the Route 550 bridge, and Section 15 extends for 1.4 miles from the McCoy Dam site. Values for length intervals represent the upper limit of each interval.
Brown trout that are >457 mm (18 in.) and >508 mm (20 in.) long seem to be the most prized sizes for anglers. In 2000, Spring Creek between Oak Hall and Milesburg was sampled, including Fisherman’s Paradise, and 5,903 age-1 and older (>150 mm; 6 in.) brown trout were measured. Among these fish, eight were >457 mm long and only one was >508 mm long. Although Spring Creek supports large numbers of brown trout, the highly prized large fish are relatively scarce.
Jason E. Detar, Fisheries Biologist, Division of Fisheries Management, Pennsylvania Fish and Boat Commission,
David Kristine, Fisheries Biologist, Division of Fisheries Management, Pennsylvania Fish and Boat Commission