Herrero, I. 2004. Risk and strategy of fishers alternatively exploiting sea bream and tuna in the Gibraltar Strait from an efficiency perspective. e ICES Journal of Marine Science, 61: 211e217.While in the last few years interest in efficiency analyses has increased among fisheries economists, efficiency analyses have not been used so far to compare the profitability of alternative fisheries. We compared the profitability of the sea bream fishery and the tuna fishery, both operating in the South of Spain (Gibraltar Strait), based on an efficiency analysis and on a comparison of the efficient frontiers of the two fisheries. Results for 2002 show that, even if the sea bream is a higher-value species than tuna, the profitability of the latter is higher. However, sea bream still appears to be the target species of the fleet whereas the tuna fishery appears only as an alternative fishery.The key reason appears to be that the latter involves more risk than the former. The management of each fishing vessel seems related to the management strategy of the captain and to his assessments of risk.