Introduction: pain and distress in fish: a review of the evidence.

A s evidenced in Paleolithic cave paintings of fi sh dating from 17,000 years ago, human-fi sh interactions have existed for thousands of years (Valladas et al. 2001). The earliest interactions likely involved fi sh as food and were necessarily tied to geographic access (i.e., island or coastal locations). Over time, the establishment of farm fi shing and the emergence of modern capture and transportation methods for wild-caught fi sh have encouraged more widespread consumption of fi sh, as have the health benefi ts of fi sh as a dietary component (Calder and Yaqoob 2009). According to the WorldFish Center, worldwide per capita fi sh consumption doubled in the past half-century, from about 8 kilograms in the early 1950s to about 15.8 kg in 1999 (Ahmed 2009). As societies moved beyond survival needs, human-fi sh interactions developed beyond those of fi sh as food. Angling and sport fi shing have become common practices in which not all fi sh caught are used for food. But there is controversy in both the scientifi c literature and the general press about whether catch and release methods are distressful for fi sh or inhumane. The Chinese developed another nonfood use for fi sh: reports from the Sung dynasty, dating back to 960 AD, indicate that keeping ornamental fi sh in ponds was a hobby for the privileged. Today in China and other countries, the confi nement of ornamental and tropical fi sh both publicly (in aquaria) and privately (in ponds and tanks) is still quite popular. As with the arguments against sport fi shing, however, there is controversy about the appropriateness of keeping fi sh simply for human pleasure. More recently, the use of fi sh as research animals has increased signifi cantly. Although fi sh were the subject of scholarly articles from the 1860s (Ransom 1867), the accounts were primarily descriptive of fi sh anatomy and physiology. In the early 1950s, the research focus shifted with the Lysa Pam Posner