Aquaculture, the fastest growing sector of global food production, accounts for nearly 40% of aquatic production and will soon surpass capture fisheries, forecast to collapse by mid-century. While “animals are not essential” (Harlan, 1995), fish and shellfish make up a substantial portion of human diet, supplying protein and nutrients essential for human development and health. Aquaculture relies largely on natural reproduction or hatchery propagation of wild stocks and boasts few domesticated species (common carp, rainbow trout, Atlantic salmon). There are enormous challenges in conserving while utilizing the planet's imperiled aquatic biodiversity. Overfishing, introduction of nonnative species, adverse interaction of wild and farmed stocks, and ocean warming and acidification are risks to aquatic genetic resources. The high fecundity of marine fish and shellfish, in particular, creates the risk that release or escape of large, hatchery-propagated families will dilute the genetic diversity of wild populations. Research on developing and improving domesticated stocks for aquaculture should have high priority alongside research on reducing or eliminating interactions with wild populations. There is an opportunity that Jack Harlan would have relished, to document the domestication process in aquaculture, though its course in the human-dominated world is likely to differ markedly from that of plant and animal domestication.

Aquaculture