In aquaculture, the lines are often blurred — fishing may be involved in production. For example, Bluefin tuna farms obtain their stock by fishing. These farms also fish for feed, and use 10 to 20 kilograms of fish for every kilogram of tuna they produce.

The primary source of information about the world's fisheries and aquaculture enterprises is the United Nations' Food and Agriculture Organization (FAO). However, the authors explain that the reporting of data from many developing and developed countries to the FAO is incomplete. They note that for the 52 percent of countries that do submit adequate data, "adding a hybrid production category would help elucidate their national understanding of domestic seafood production, as well as enhance global understanding of an important food sector."

The authors conclude by stating the urgency of adding the hybrid category: "Without these data, transformations in the market for a critical food and livelihood source for billions of people could occur, with global analysts and policymakers being the last to know."

The team responsible for the article, the NCEAS Working Group on Envisioning a Sustainable Global Seafood Market and Restored Marine Ecosystems, includes ecologists, economists, policy analysts, members of the seafood industry, and marine conservation organizations.

In addition to Klinger and Turnipseed, the authors are Benjamin S. Halpern, NCEAS; Kimberly A. Selkoe, NCEAS and the Hawaii Institute of Marine Biology; James L Anderson, University of Rhode Island; Frank Asche, the University of Stavanger, Stavanger, Norway; Larry Crowder, the Center for Ocean Solutions, Monterey, Calif.; Atle G. Guttormsen, Norwegian University of Life Sciences, Aas, Norway; Mary I. O'Connor, University of British Columbia; Raphael Sagarin, University of Arizona; Geoff Shester, Oceana, Monterey, Calif.; Martin D. Smith, Duke University; and Peter Tyedmers, Dalhousie University, Halifax, Nova Scotia.