Illustration: Zeus with Amalthea and nymph

The ancient Greeks told a story, which may have originated more than 2,500 years ago, of the infant Zeus, who was destined to be King of the Gods. Hidden from his father, Chronos, who planned to devour him, Zeus survived by drinking the milk of the she-goat Amalthea. Yet even as a small child, Zeus was very powerful; one day while he was nursing, he accidentally broke off one of Amalthea’s horns.

The horn was imbued with magical powers, making it able to provide a never-ending supply of nourishment. Some versions of the myth say that Amalthea’s horn would provide its owner whatever he or she wished for.

The Greeks called it the “Horn of Plenty,” but when the Romans adopted the myth, they called the horn “Cornucopia.”

Today, some people want to call it “the ocean.” At least, that’s how it seems.

In 1884, biologist Thomas H. Huxley said, “Probably all the great sea-fisheries are inexhaustible; that is to say that nothing we do seriously affects the numbers of fish.”

Sadly, we’ve learned that Huxley was very wrong. Even as he recorded those words, they were being proved wrong. Atlantic halibut, according to the National Marine Fisheries Service (NMFS), were already “heavily overfished in the 19th century,” so badly overfished that, “there are no signs of recovery to date.”

Since then, overfishing has led to the decline of many species in many different places, although none may be as symbolic, or as historically tragic, as the collapse of the cod fishery off New England.

Despite that, it seems that some people still believe that the ocean is a cornucopia, an inexhaustible source of fish that will supply whatever such people believe they need.

That unfortunate fact was recently illustrated in an article that appeared in The Fisherman magazine, which quoted a fishing tackle industry representative who spoke at a recent Washington, D.C. meeting. In making his case as to why the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens) should be amended, and its conservation and stock rebuilding provisions weakened, that industry spokesman said,

That speaker makes it clear that he, and the various industry groups and anglers’ rights organizations that seek to amend Magnuson-Stevens, are living in a mythical world, in which the ocean is an inexhaustible cornucopia that will always be capable of supplying the needs of expanding businesses and a growing population of anglers. That mythical mindset is in direct contradiction to the real-world premise that underlies current federal fisheries law, which treats the ocean as a marine community governed by the rules of biological sustainability.

The current process of setting annual catch limits for both commercial and recreational fishermen, as required by Magnuson-Stevens, is both simple and logical. The first step is to set the overfishing limit, to assure that harvest does not exceed maximum sustainable yield. Since maximum sustainable yield equates to “the maximum crop that can be removed from a population of animals or plants without adverse effects” [emphasis added], it represents an important threshold that must not be crossed; if it is, the affected fish stock will become less productive and less able to support viable fisheries in the long term.

Because the data used to calculate the overfishing limit is not perfectly precise, Magnuson-Stevens also requires that each regional fishery management council’s science and statistical committee evaluate the level of scientific uncertainty in the data, and establish an acceptable biological catch for each stock, which will almost always be somewhat lower than the overfishing limit. If that wasn’t done, and managers established annual catch limits that equaled the maximum sustainable yield for a stock, any scientific uncertainty at all could easily lead to overfishing.

Such process helps to ensure that overfishing won’t occur, and allows stocks to recover to the level that can safely produce the highest sustainable yields and economic returns. It implicitly recognizes that fish stocks are not inexhaustible, and that harvests cannot increase beyond sustainable levels merely because there is an increase in demand. For as cod, winter flounder and a host of other fish stocks have taught us, once harvest exceeds maximum sustainable yield, abundance inevitably declines and, in the long run, provides less fishing opportunity for everyone.

And that’s where the industry representative quoted above went wrong. He complained that “The law needs to recognize that in its current form, our tradition of fishing cannot be passed onto our children without [Magnuson-Stevens] taking away opportunity from the rest of the fishing community.” But it’s not Magnuson-Stevens that limits the opportunity for harvest; basic biology does that. Magnuson-Stevens merely prevents fishermen from ignoring biological realities and driving stocks into decline.

Fishermen have been doing that for a very long time. In the late 19th century, Atlantic sturgeon were so abundant in the Hudson River that they were nicknamed “Albany beef,” and supported a substantial commercial fishery. Like the Atlantic halibut population that crashed at the same time, Atlantic sturgeon couldn’t support an expanded fishery; the population collapsed and never recovered. In 2012, the United States Fish and Wildlife Service determined the Hudson River stock to be endangered.

A number of other stocks became seriously depleted over the years, and it was that depletion that led to the passage of the Sustainable Fisheries Act of 1996 (SFA), a bill that amended Magnuson-Stevens into the effective fishery management tool that it is today.

Prior to SFA, federal law allowed fisheries managers to establish “optimum yield” from a fishery “on the basis of the maximum sustainable yield from such fishery, as modified by any relevant economic, social, or ecological factor” [emphasis added]. Predictably, managers used that language to justify overfishing, which allowed fishermen to enjoy greater short-term economic benefits. However, because such overfishing led to a long-term decline in both abundance and economic returns, SFA amended the provision, replacing “modified” to “reduced,” so that economic concerns couldn’t be used as an excuse to overharvest.

Now, it appears that at least some members of the recreational fishing community are trying to turn back the clock, and again allow stocks to be overfished in the name of a “flexibility” that will “allow for new entrants to come into the fishery and businesses to grow and expand.”

That approach didn’t work prior to SFA, and there is no reason to believe that it will be any more successful in the future.

For Thomas Huxley was wrong, fish stocks are not inexhaustible. And the bottomless cornucopia was, after all, just one more Greek myth.