1998 

 OUR LIVING OCEANS 



Landings 



(X 1,000,000 



pounds) 



14 - 



12 - 



10 - 



30%SPR 



ABC midpoint 



89- go- 

 go 91 



91- 

 92 



92- 

 93 



93- 

 94 



94- 

 95 



95- 

 96 



96- 

 97 



97- 

 98 



Figure 4 



Total catch (x 1,000,000 

 pounds) that actually oc- 

 curred in the fishery com- 

 pared to the three scenarios 

 described in Figure 3. 



Fishing year 



ing mortality rate (f'^,,,,,,"') had been applied, tlie 

 trajectory ot SPR would have been a gentle in- 

 crease to the recovery level during the recovery 

 period, as expected (Figure 3). Comparing the 

 catches from the F,,,,,^^ trajectory with those from 

 the actual TAG and ABC midpoint trajectories, it 

 is seen that the FAC's chosen would in fact be risk- 

 averse relative to the F,,,,,^^ values, at least initially, 

 and thus allow a faster recovery. Had risk-prone 

 TAC's been set each year, that is TAC's larger than 

 those corresponding to the F,,,,, trajectory, the 

 king mackerel would not have recovered to levels 

 of 30% SPR during this time period. In fact, these 

 "what if" scenarios are conservative in that they 

 assume the same recruitment occurred. If recruit- 

 ment had ftirther increased with the increase in 

 biomass (it appears there is a relationship in this 

 stock), then this would accentuate the differences 

 between the scenarios. 



DISCUSSION 



The Gtilf of Mexico king mackerel fishery is 

 an example of how catches can increase while fish- 



*'rhf spawning potential ratio i.s the amount of reproductive 

 output for one recrtiit relative to the amount expected under 

 no fishing (sec Appendix 4). F„|„„ and H^,,,,,, are the fishing 

 mortaliiy rales expected to produce 30% Sl'R and 40% SPR, 

 respectively. 



ing mortalit)' rate(s) decreases, and biomass in- 

 creases, a win-win situation for the fishery and the 

 fish stock. All that is left is to take the final step to 

 full recovery of the species, which will require a 

 reduction in catches and/or further improvement 

 in recruitment. Although it is a complex fishery 

 consisting of migratory groups which overlap in 

 distribution and are exploited mainly by recre- 

 ational anglers whose total catch cannot be easily 

 measured, the potential exists to fully recover the 

 stocks while providing food, employment, and so- 

 cial benefits to the Nation for generations to come. 

 This recovery will require not just the setting of 

 risk-neutral TAC's, but also a recovery trajectory 

 and a plan to compensate when the TAC alloca- 

 tions are not filled exactly, thereby moving away 

 from the recovery trajectory (Powers, 1996). Fhe 

 seemingly random nature of recruitment lewis and 

 possible influence of environmental conditions 

 means there will always be imperfect implemen- 

 tation of a recovery trajectory. The ability to com- 

 pensate for falling behind the planned trajectory 

 or to take advantage of improved conditions would 

 significantK' increase the probability of achieving 

 stock recovery while maintaining viable fisheries. 



LITERATURE CITED 



Legault, C. M., N. Cummings, .uid P. Pliarcs. 1998. 

 Stock assessment analyses on Atlantic migratory group 

 king mackerel, Gulf of Mexico migratory group king 

 mackerel, Atlantic migratory group Spanish mackerel, 

 and Gulf of Mexico migratory group Spanish inack- 

 erel. National Marine Fisheries Service, Sustainable 

 Fisheries F)ivision Contribution MIA-97/98-15, Mi- 

 ami, Florida, 90 p. 



MSAP (Mackerel .Stock .Assessment Panel). 1998. Re- 

 port of the Mackerel Stock Assessment Panel. Gulf o( 

 Mexico and South Atlantic Fishery Management 

 Councils, 29 p. 



Powers, J. F. 1996. Benchmark requirements for re- 

 covering fish stocks. North American journal of Fish- 

 eries Management 16:49'i-S()4. 



SFP (Socioeconomic Panel). 1998. Report ol the Sev- 

 enth Coastal Migratory Pelagics Socioeconomic Panel 

 Meeting. Gulf of Mexico Fishery Management t'oun- 

 cil, Tampa, Florida, 36 p. 



86 



