Sportfish population dynamics in Lake Mattamuskeet, 2013, and discussion of an active lake level management plan to enhance these fisheries

SPORTFI SH POPULATI ON DYNAMI CS I N LAKE MATTAMUSKEET, 2013, AND Dl SCUSSI ON OF AN ACTI VE LAKE LEVEL MANAGEMENT PLAN TO ENHANCE THESE FI SHERI ES Federal Aid in Sport Fish Restoration Project F-108 Final Report Kathryn M. Potoka Jeremy W. McCargo Chad D. Thomas North Carolina Wildlife Resources Commission Division of Inland Fisheries Raleigh 2014 Keywords: Largemouth Bass, Black Crappie, Bluegill, electrofishing, trap nets, coastal region This project was funded under the Federal Aid in Sport Fish Restoration Program utilizing state fishing license money and federal grant funds derived from federal excise taxes on fishing tackle and other fishing related expenditures. Funds from the Sport Fish Restoration Program are used for fisheries management and research, aquatic education, and boating access facilities. The program is administered cooperatively by the N.C Wildlife Resources Commission and the U.S. Fish and Wildlife Sen/ice. Abstract.— Largemouth Bass Micropterus salmoides and Bluegill Lepomis machrochirus, were sampled in shoreline electrofishing transects in main lake sites on Lake Mattamuskeet, Jarvis Canal, Main Canal, and Rose Bay Canal in October 2013. Black Crappie Pomoxis nigromaculatus were sampled in Main Canal and Rose Bay Canal using trap, hoop, and fyke nets in November 2013. Largemouth Bass length frequency and PSD analysis indicated a healthy and balanced population in the canals, but low water levels prevented adequate sampling within the main lake sites. A total of 174 Largemouth Bass were collected from the canals, whereas only 16 were collected from the main lake samples. Multiple size groups were collected from the canals, and mean relative weight (Wr = 97.5) suggested Largemouth Bass were in excellent condition. Abundance of Largemouth Bass greater than 200 mm was higher in Jarvis, Main and Rose Bay canals (mean CPUE 45.5 fish/h) than in the main lake (12.1 fish/h). Overall, the Bluegill sample was comprised mostly of stock length fish (80-149 mm) and had very few fish greater than preferred length. Abundance of stock-length and greater Bluegill in the canals (88.7 fish/h) was greater than in the main lake (56.8 fish/h). Standard trap nets with 25.4-mm mesh were most efficient at capturing Black Crappie in Main Canal and Rose Bay Canal. Length frequency distributions of Black Crappie in Main Canal and Rose Bay Canal had a wide range of sizes indicating multiple age classes. The majority of Black Crappie were fast-growing age-1 fish with fish up to age 6 collected; however, mortality offish >age 3 was apparently high. No age-0 Black Crappie were collected indicating a potential failed year class. Future efforts should focus on assessing the extent of possible year class failures for Largemouth Bass and Black Crappie and the relationship with water quality and lake levels in the main lake and associated canals. The NC Wildlife Resources Commission recommends that the USFWS Mattamuskeet National Wildlife Refuge implement an active lake level management plan that focuses efforts throughout the year to hold water levels of either 2.1 ft (east side) or 2.3 ft (west side) within ±0.2 ft as measured at the permanent USGS gauging stations to promote quality and quantity of fisheries habitats in the main lake. 1