That ratio measures the current reproductive ability of a given fish species against what that ability would be in unfished waters. For sharks, which are not as prolific as bony fish, the threshold for overfishing was set at 0.35. In contrast, most sharks produce between 2 and 50 young per year, take a long time to reach reproductive age and live long lives between 12 and 70 years depending on the species. The Council's Plan Team for pelagic fish acknowledges that it lacks the information needed to assess the health of shark stocks. Although shark data are required to be reported on longline logbooks, it is not certain if sharks that are caught, finned, and disposed of at sea are adequately reported.
Species identifications are also commonly inadequate.
Since most sharks have low reproductive rates and long gestation periods, they are highly sensitive to fishing pressure. If what is occurring here is anything like what has happened elsewhere, shark stocks may be experiencing what has been described as a dizzying ecological plunge. Without drastic conservation measures, some species will be lost. Without sharks, marine ecosystems could be thrown out of balance in ways still not well understood but certainly damaging. And for that, we need sharks.