The "spillover effect", as fish migrate out of large marine reserves, greatly boosts the overall catch levels.
Hundreds of boats enter each year, competing for trophies in a Bay and Surf Division and an Offshore Division and for the grand champion award for the best overall catch.
If fishing in certain areas is banned altogether, according to these researchers, the overall catch can be increased, and in a sustainable way.
By limiting the overall catch and allowing people to buy and sell their fishing rights, the system encourages some to leave the business, said William Hogarth, director of the National Marine Fisheries Service.
Faced with calls to end the catch completely in 2008, members of the International Commission for the Conservation of Atlantic Tunas, or Iccat, agreed to regulate fishing more strictly, adding documentation requirements and reducing the overall catch.
If some fishermen catch more fish and others catch less, it has no effect on your share of the overall catch.
Although these species accounted for just 7% of overall catch, most were tiger and bull sharks, the most likely culprits in the attacks.
The largest number (83) of these were used at Kenilworth Castle where the overall catch rate was lower (p < 0.07, Mann–Whitney U test) in PFTs, 0.65 compared with 2.49 for the 276 simple blunder traps.
Overall catch volume has not changed greatly because the decline in high-value species has been offset by increased catches of less valuable fish such as Alaskan pollack, Peruvian anchoveta, Chilean jack mackerel and South American and Japanese pilchards.
