Bureau of Technical Brief #tb919009

Oatka Creek Population Estimate Scott Cornett, Region Nine Fisheries 11/26/19

Oatka Creek, south of the Village of Warsaw in Wyoming County, provides a for wild . It is also stocked each spring with hatchery and brown trout. There are no public fishing rights easements on Oatka Creek and access is only on privately owned, non-posted lands. Oatka Creek is managed as a year-round trout fishery, with the period from October 16- March 31 restricted to , with artificial lures only allowed. In 2019, as part of region-wide trout population monitoring, Oatka Creek was sampled by electrofishing at two sites. They were located at Munger’s Mills Road and at the Route 19 bridge below the falls in Rock Glen and totaled 760 feet of stream. Both sites were previously sampled six times between 1991 and 2018. To estimate the trout population abundance, we utilized two electrofishing passes in 2013- 2019. Prior to this we utilized single pass methodology.

In 2019, we captured 35 yearling and Figure 1. Length distribution of stocked and wild brown older (adult) wild brown trout along trout captured at both sites in Oatka Creek, 2019. with eight stocked yearling brown trout. No stocked brook trout were 10 captured. Adult wild brown trout ranged in length from 4.8 to 15.9 8 trout

stocked inches (Figure 1), with an average length of 8.5 inches. Stocked brown 6 wild brown

trout ranged from 8 to 10 inches of 4 (Figure 1). At the Route 19 site, we found an adult wild brown trout 2 abundance of 191 fish/mile (±15) Number (Figure 2). At our site at Munger’s 0 Mill Road in 2019, we found a higher 4 5 6 7 8 9 10 11 12 13 14 15 abundance of adult wild brown trout Length group (inches) (289 fish/mile (±27)) (Figure 2). As with past surveys, no young-of-year trout were captured at either site and it is believed that most reproduction occurs in the areas above Rock Glen and in upstream .

Wild brown trout abundance at the Route 19 site in 2019 was much lower than we found in 2001- 2018 surveys and only slightly higher than we found in 1991 (Figure 2). No stocked brown trout were captured at this site. Similarly, the abundance for wild brown trout at our Munger’s Mills Road site in 2019 was also lower than most survey years, including in 2018 when we found the highest abundance we had recorded at this site (Figure 2). Stocked brown trout were also substantially less abundant (105 fish/mile (±27)) at this site than in 2018 or most other survey years. Trout population estimates could not be obtained at Munger’s Mills Road in 2017 due to poor electrofishing efficiency. However, based on the total number of fish captured in 2017, it appears that the abundance of wild brown trout at this site was similar to 2016 values. No long-

800 Figure 2. Adult wild brown trout abundance at both sites on term trends were apparent for Oatka Creek, 1991‐2019. Error bars represent 95% confidence wild brown trout at either site, limits. 700 however there has been a Route 19 Site significant short-term decline observed at the Route 19 site 600 Mungers Mills Rd Site from 2016 to 2019 (Figure 2). Hatchery brown trout are stocked

mile 500 in May, while the stream receives per 400 brook trout in the early-April stocking. As with this year, we 300 did not capture any stocked

Number brook trout in 2016 or 2018, while 200 in 2013 and 2017 very low numbers were captured. It 100 appears that stocked brook trout do not survive long into the 0 season in this stream, being lost 1991 2001 2013 2016 2017 2018 2019 to angler harvest, natural mortality and/or migration out of the stocked section. Based on this year’s sampling, it appears Oatka Creek will continue to provide satisfactory fishing for anglers wishing to pursue wild and stocked brown trout and for stocked brook trout early in the season. No changes to regulations are expected for Oatka Creek in 2021, based on the 2020 state-wide Inland Trout Stream Management Plan. However, the stocked section of the stream will be shortened on the upper end, due to the high abundance of wild brown trout.