2017. TRAC Georges Bank Yellowtail Flounder Status Report 2017/03

Combined Canada and USA catches in 2016 were 44 mt. This is the lowest value in the time series beginning in 1935. The declining trend in survey biomass to low levels, despite reductions in catch to historical low amounts, indicates a poor state of the resource. Recent catch is low relative to the biomass estimated from the surveys but catch curve analyses indicate high total mortality rates (Z above 1 for most years). Stock biomass is low and productivity is poor. The empirical approach adopted in 2014 averages estimates of biomass from the DFO, NMFS spring, and NMFS fall surveys, and applies an exploitation rate to this average to generate catch advice. The consensus of the 2017 TRAC intersessional meeting was to change survey catchability from 0.37 to 0.31 and to use wing width instead of door width to compute the area of a survey tow. Under these assumptions, average survey biomass is calculated to be approximately three times higher throughout the time series, but the trend does not change. The TRAC external reviewers and science members recommend an exploitation rate between 2% and 6% for catch advice, which results in 62 mt to 187 mt for 2018.

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