“Caution is a most valuable asset in fishing, especially if you are the fish.”

The author of this clever truism, whose identity has been lost to posterity, probably had no idea just how right he was. A lack of caution, it now seems, has endangered a $7 billion dollar-a-year industry.

After the sighting of a single Asian carp this past June, everyone from the National Wildlife Federation to the U.S. Army Corp of Engineers is close to panic. These giant carp, originally imported to control the spread of algae in Arkansas fish farms, escaped into the Mississippi River during the great flood of 1993 and have been steadily making their way northward.

The last line of defense has been a man-made canal built a century ago to link the Mississippi River with the Great Lakes. By running electric current through this narrow waterway, officials believed they could block the progress of the invasive fish. Now they are not so sure.

Able to eat 40 percent of their body weight each day and lacking any natural predators, the Asian carp can grow to over a hundred pounds and four feet in length, crowding out smaller fish and thereby threatening the survival of the fishing industry. Some argue that the only remaining solution is to shut the Chicago area shipping locks, thereby shutting down commercial traffic as well. A judge’s decision is currently pending.

Delicate Balance

Who would have thought that a few fish could ever cause such a tumult?

The Torah Sages of antiquity, of course.

In the narrative of Creation, the Torah records that “God called the dry land earth, and the gathering of waters He called seas” (Genesis 1:10). The Sages wonder why the waters of our planet, which are contiguous and therefore might be considered one single ocean, are designated in the plural. They answer that the Torah wishes to teach us that “the taste of the fish from the waters of Sidon (western Asia) is not similar to the taste of fish from the waters of Spain.” In other words, each sea – and consequently, the fish that come from it – has its own distinct character.

The fish of each sea has a distinct character.

The subtlety of Biblical Hebrew suggests a deeper layer of meaning. The word for “taste” – ta’am – also means “reason” or “judgment.” These faculties of intellectual discernment are the means through which we are able to recognize and respect the boundaries of nature (and more abstractly, the boundaries between right and wrong). Accordingly, we can understand that the Torah is providing a lesson in appreciating the delicate balance of nature, and a warning against violating the boundaries designed to protect the natural order of our world.

The Asian carp is only the most recent example of relocated species gone wild. The European rabbit, introduced to Australia in 1859, has reached a population of over 200 million, necessitating the construction of a 2,000-mile-long rabbit-proof fence to prevent the wholesale destruction of farmlands. In 1956, African bees brought over by Brazilian scientists to breed for honey production escaped their quarantine and gave rise to the noted “killer bee” scare.

In 1884, a farmer visiting the Cotton States Exposition in Louisiana brought back a few Venezuelan water hyacinths to decorate the fountain outside his home in Florida. Today, the aggressive purple flowers choke 126,000 acres of waterways. Kudzu, a Japanese vine imported in 1876 to prevent erosion, in currently spreading through the southern United States and expanding at a rate of 150,000 acres a year.

The list goes on and on. In the United States alone, containment costs of invasive species are estimated at $138 billion annually.

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Forbidden Mixtures

By definition, the law of unintended consequences is a principle that can be appreciated only in hindsight. We cannot anticipate every outcome of any action, particularly when we dare to impose our vision of a better world upon the natural order we have inherited from our Creator. Sometimes human dabbling in nature produces obvious benefits, like the tangerine and the mule. Occasionally, science finds solutions that provide immeasurable joy, as it has by developing cures for diseases and procedures such as in vitro fertilization. But experience has proven repeatedly that violation of the boundaries of nature should be approached with circumspection and trepidation.

Active and passive inclinations struggle within our hearts.

This explains why Torah law includes numerous types of forbidden mixtures. The laws of shatnez, which disallows combining wool and linen in a single garment, and the prohibition against any mixture of milk and meat, both derive from the need to respect the boundaries between the animal and plant kingdoms, which respectively symbolize the active and passive inclinations that struggle against one another within hearts of men. It may have been with this idea in mind that King Solomon observed, “There is… a time to be silent, and a time to speak” (Ecclesiastes 3:7).

Similarly, the Torah prohibits hitching an ox and donkey together to pull one’s cart, and prohibits planting different varieties of fruit trees in a single orchard. Certain kabbalists have gone so far as to avoid interlacing the fingers of the left hand (symbolizing the divine attribute of justice) with the fingers of the right hand (symbolizing divine mercy). Every such example contains a unique insight into acquiring respect for the integrity of nature’s laws and limitations.

Nature itself forces us to take stock of the damage we have caused to our world through careless disregard for the boundaries of Creation. At the same time, it compels us to consider that the moral and spiritual boundaries that govern civilized society are no more variable or inconstant than the laws that define the physical universe. If we take these warnings to heart, we can look forward to a future that is more ordered and defined, more stable and more secure. And that is nothing to carp about.