Characteristics of the 2015 Roanoke River striped bass spawning population

CHARACTERISTICS OF THE 2015 ROANOKE RIVER STRIPED BASS SPAWNING POPULATION Aid in Sport Fish Restoration Project F-108 Report Type: Survey Christopher A. Smith Jeremy W. McCargo Kathryn M. Patoka North Carolina Wildlife Resources Commission Inland Fisheries Division Raleigh 2016 Keywords: Striped Bass, Roanoke River, electrofishing, spawning stock assessment, 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 Service. Abstract. — An electrofishing survey for spawning Striped Bass Morone saxatiliswas conducted near Weldon, NC, in the spring of 2015. Weekly surveys collected a total of 1,867 Striped Bass. Males represented 86.9% of the total catch, while females represented 13.1%. Overall relative abundance of Striped Bass was 169.4 fish/h. Peak relative abundance of 307.8 fish/h occurred on May 4, 2015. The low CPUE in 2015 continued a decreasing trend in relative abundance that has been seen since 2006. Age analysis indicated that the 2015 population was composed mainly of age-3 (2012 year class; 42.7%) and age-4 (2011 year class; 44.3%) fish. Relative abundance of older fish (> age-9) was 1.46 fish/h and remained below the long-term average of 4.7 fish/h. In 2015, 41.2% of all males and 71.9% of all females were available for potential harvest, but only 0.74% of all males and 7.8% of all females were available for harvest above the protective slot limit (662 mm). Annual mortality estimates for the 1992 to 2009 cohorts ranged from 0.30 (1995) to 0.67 (2002). An increasing trend in cohort mortality was observed, with more recent year classes (2001- 2009) having mortality rates above 0.50. High mortality rates experienced by recent cohorts are likely the cause in reduction in relative abundance of fish older than age 9. 1