Wild Things

Big, Old, Fat, Fertile, Female Fish Keep Fisheries Afloat

Isn’t she lovely, folks?

Photo sourced from a press release

No, the name is not an insult. Big, old, fat, fertile (or fecund) female fish, or BOFFFF, is a term of respect among scientists. These fish are actually a much better breeding bet than their younger, more svelte counterparts, according to a new study published in a special issue of the ICES Journal of Marine Science. The merits of these older (certainly wiser) aquatic matriarchs have long gone underappreciated. BOFFFFs are prolific baby-makers—which means they’re better at helping fisheries stay sustainable and fend off stock collapse.

Unfortunately, their ample bodies also make great trophies for fishermen.

The study compiled research from around the world and found that BOFFFFs are vital in keeping fishery stocks sustainable.

These fish produce more and larger eggs than smaller mature females. Their eggs, the study found, may also develop into larvae that grow faster and are less susceptible to starvation. BOFFFFs also enjoy longer spawning seasons, and might spawn in different places from their slimmer counterparts. These features, the study points out, hint that BOFFFFs are simply a better bet because they can outlive unfavorable reproduction conditions, and still be ready to “spawn profusely” next season. Scientists call this “the storage effect,” but most people would probably just call it “being a tough cookie.”

“Increasingly, fisheries managers are realizing that saving some big old fish is essential to ensure that fished populations are stable and sustainable,” said study author Mark Hixon of the University of Hawai’i at Mānoa in a press release.

But despite their survival savvy, keeping BOFFFFs alive might not be as simple as it sounds. Fishermen love a good trophy, and bigger fish also just look more delectable than punier fish. The study says the two most viable options to protect these fertile females are “slot limits” and marine reserves. The former is regulation that says only medium-size fish may be captured—none smaller or larger than a strict size limit. The latter makes certain parts of the ocean off-limits to fishing entirely, which allows some fish to spawn through their entire lifespan, and for their offspring to replenish fished populations outside the reserve.

These ideas aren’t new, but the study suggests one factor slowing their adoption is the perceived difficulty of implementing them. But, the study also says, “Change is in the air.” The study says stock assessments, sets of biological information that helps fisheries regulate their stocks, for 12 of 19 rockfish species now include age or size-dependent relationships with relative fecundity—in effect giving BOFFFFs their due. Perhaps having this information on hand could turn the tide and motivate fisheries to keep their big, old, fat, fertile, female fish around longer.