Stock Status and Conservation Information
(From ISC19 Plenary Report)
Pacific Blue Marlin
Click here to see the ISC18 stock status and conservation information.
Stock Status
Estimates of total BUM stock biomass show a long term decline. Population biomass (age-1 and older) averaged roughly 130,965 t in 1971-1975, the first five years of the assessment time frame, and has declined by approximately 40% to 78,082 t in 2014. Female spawning biomass was estimated to be 24,809 t in 2014, or about 25% above SSBMSY. Fishing mortality on the stock (average F, ages 2 and older) averaged roughly F = 0.28 during 2012-2014, or about 12% below FMSY. The estimated SPR of the stock (the predicted spawning output at the current F as a fraction of unfished spawning output) is currently SPR2012-2014 = 21%. Annual recruitment averaged about 897,000 recruits during 2008-2014, and no long-term trend in recruitment was apparent. Overall, the time series of spawning stock biomass and recruitment estimates show a long-term decline in spawning stock biomass and a fluctuating pattern without trend for recruitment. The Kobe plot depicts the stock status relative to MSY-based reference points for the base case model and shows that spawning stock biomass decreased to roughly the MSY level in the mid-2000s, and has increased slightly in recent years.
Based on these findings, the following information on the status of the BUM stock is provided:
- No target or limit reference points have been established for the BUM stock;
- The Pacific BUM stock is not currently overfished and is not experiencing overfishing relative to MSY-based reference points;
- Because Pacific BUM is mainly caught as bycatch, direct control of the annual catch amount through the setting of a total allowable catch may be difficult.
Conservation Information
Since the stock is near full exploitation, the ISC recommends that fishing mortality remain at or below the most recent levels estimated in the 2016 assessment (average 2012-2014).
