Why Big, Old, Fat, Fertile Female Fish Are The Rockstars Of The Ocean

The next time you catch a BOFFFF, maybe you should throw her back.

A growing collection of research shows that big, old, fat, fertile female fish -- what scientists call BOFFFFs -- are critically important to ocean fisheries because they’re basically rockstars of reproduction.

Conventional wisdom has held that, in order to protect ocean stocks and maintain strong populations, fishermen should catch big fish but release smaller ones so that they can grow, produce eggs and continue the circle of life.

But in the October 2014 issue of the “ICES Journal of Marine Science”, three experts argue that fishing efforts should focus on medium sized fish, rather than snatching out and bragging about the huge ones.

“The loss of big fish [often] decreases the productivity and stability of fishery stocks,” explained Mark Hixon, a marine biologist at the University of Hawaii at Mānoa, who published the paper with California State University marine biologist Darren Johnson and NOAA Fisheries ecologist Susan Sogard. Such loss, the trio wrote, can lead to a fish population’s collapse.

BOFFFFs are so vital because they produce more and larger eggs that have a better chance of developing into larvae that can withstand threats, the paper posits. BOFFFFs also tend to have longer spawning sessions, may spawn in a wider range of locations than smaller fish, and are more likely to survive bad years, reproducing feverishly when conditions improve.

The BOFFFF hypothesis -- and that funny name -- is credited to biologist Alan Longhurst and late fisheries ecologist Steven Berkley, who noticed that older, bigger fish produced exponentially more eggs than younger females.

"Smaller females are more susceptible to predation, and so may be more restricted to safer habitats and thus different food supplies," Hixon told Marine Protected Areas News in 2007. "Smaller females must also devote more energy to growth than larger females, which can devote more energy to reproduction."

His latest report says that, by implementing slot limits (regulations in recreational fishing that only allow for the catching of medium sized fish), establishing marine reserves, or reducing our exploitation rates, the productivity and stability of fisheries would likely ensure that “pockets of old-growth age structure survive.”

The moral is honor thy BOFFFF, in other words -- especially if you want to ensure long term replenishment and stability in your fishing community.