History of Marine Stock Enhancement Programs in the USA
Discovery stage -- Americans have had a fascination with the idea of stocking hatchery-reared organisms to enhance marine fisheries dating back to the latter part of the nineteenth century. In 1866, the famous Norwegian biologist, G. O. Sars, led the first successful attempt to cultivate eggs and early larvae of totally marine fishes (Shelbourne, 1964). By 1880, US biologist Spencer Baird had successfully repeated Sars' experiments in Gloucester, Massachusetts, and produced the first crop of cod eggs at the new field station at Woods Hole. Sars' display of his work 3 years later at the Fisheries Exposition in London had a great impact on European fisheries biologists. This quickly resulted in construction of the finest marine hatcheries of that time, in 1883 by the Norwegians at Flødevigen, followed by the Dunbar hatchery in 1893 on the east coast of Scotland. These hatcheries were soon producing millions of cod fry (Kirk, 1987), and marine fish culture seemed promising as a fishery-management measure to supplement fishing restrictions.
Production phase -- The approach to marine stock enhancement during most of the twentieth century can be characterized as the production phase, a period when all of the emphasis and accountability in stocking programs was focused on aquaculture production and release magnitude (Leber, 1999). Emphasis on production was long lasting, and overshadowed key questions about stocking effects on fishery landings and fish populations.
Scientific phase -- By the 1990's, technology developed to mark eggs, larvae and fry enabled assessment of survival and impact of even the smallest sizes of cultured organisms released into the sea. Modern tagging technology has enabled tag-release-recapture experiments needed to develop optimal stocking strategies and critically evaluate assumptions about stock enhancement. This has accelerated scientific discovery about stocking effectiveness. Development of more effective stock enhancement technology is beginning to accelerate in the 21st century by coupling field experiments with mathematical and economic models.
Outlook -- The US has been a leader in helping to advance the science and effectiveness of marine fisheries enhancement. Stock enhancement can, in principle, be effective at increasing the availability of fish to fisheries, providing economic benefits, rebuilding stocks that have been depleted, and encouraging institutional adaptation that can lead to more sustainable exploitation or promote habitat restoration (eg. Lorenzen, Leber and Blankenship, 2010; Leber et al., 2012; Leber, in Press). However, to ensure this, stock enhancement programs must be planned from a fisheries management perspective, and evaluated within the context of their contribution to fisheries management goals, and their effectiveness compared to alternative or additional measures such as control of fishing effort and habitat management (Lorenzen, 2008; Lorenzen et al., 2010). The Science Consortium for Ocean Replenishment is a resource for expanding this approach in the US. Expanding the SCORE approach is imperative for moving this field forward. The costs for expanding this approach are minor compared to the resources that could be wasted if it is not integrated into stocking programs across the US.