Striped Mullet FMP - NC Dept. of Environment and Natural Resources

surveys provided indices of adult CPUE and length compositions, and two seine surveys servedas juvenile abundance indices (JAI).ResultsBased on the population model results, the three highest estimates of age 0 recruitment(R 0 ) have occurred in the most recent five years, peaking in 2002. High yearly levels of R 0 arecharacteristic for the stock, averaging 61 million new recruits per year. Female spawning stockbiomass (SSB) has increased from 1994 to 2002, with peak SSB occurring over the last threeyears of the assessment.Fishing mortality (instantaneous rate, F) was estimated separately for the recreationaland commercial fisheries, notated as F r and F c . Fishing mortality was also estimated for eachJanuary-June and July-December period, referred to as F c Jan and F c Jul , as examples. Full yearfishing mortality is the sum of the seasonal F rates within a year, written as F r Tot or F c Tot .Only minor recreational fishing mortality (F r ) is incurred on juveniles from recreationalbait harvest. Recreational fishing mortality occurs almost exclusively on age 0 individuals fromJuly to December. Essentially, the large numbers of striped mullet cast netted by anglers forbait is minimal in relation to the vast numbers of age 0 recruits that are produced each year.Commercial F (F c ) is disproportionately higher on females than males and occurs withgreater intensity in July-December than in January-June. On average, 66% of the F c Tot onmales, and 91% of the F c Tot on females occurs in the July-December period. The commercialfishery also targets different age classes between the two seasons, as larger, older fish aresought in July-December. Full 100% selectivity (or full vulnerability) to the fishery occurs at age2 in January-June, and at ages 3 and 4 for males and females in July-December. These ageclasses are considered ‘fully-recruited’ to the fishery. Fishing mortality on fully recruited ageclasses is hereby referred to as ‘Full’ F.Full F c Tot on males has been stable from 1994-2002, averaging 0.80. Averagecommercial F on fully recruited females was 1.25. The heaviest exploitation on females and thelargest fluctuations in F c Tot occurred in the early years (1994-1998) of the nine-year time series.The average full commercial fishing mortality on females over the last four years of theassessment (1999-2002) was F c Tot =1.09.Overfishing DefinitionsBy definition, overfishing occurs when the fishing mortality rate exceeds the threshold Frate and the rate of removal of fish exceeds the ability of the stock to replenish itself (ASMFC2004). Yield per recruit (YPR) and spawning stock biomass per recruit (SSB/R) modeling, anda replacement analysis of observed stock-recruitment data were used for defining F-basedoverfishing thresholds for the stock. The following benchmarks and thresholds are given as fullyear fishing mortality rates on fully recruited age classes.F max and F 0.1 were used as benchmarks to assess overfishing on males. F 0.1 isconsidered a conservative proxy for fishing at maximum sustainable yield (MSY) for somespecies. Overfishing is not occurring on males, considering recent fishing mortality rates (1999-2002 average Full F c Tot =0.71) in relation to F 0.1 =0.58 and F max =1.65. It is likely that maleabundance is adequate for overall stock sustainability, considering stable commercial F rates,increasing age 0 recruitment, and the generally reduced importance of males to reproduction24