48 MARCH 2018 • WORLD AQUACULTURE • WWW.WAS.ORG be a viable way of alleviating fishing pressure on marine ornamentals collected for the aquarium trade (Calado et al. 2017). Ninety percent of freshwater ornamentals are cultured, although the proportion of marine ornamentals reared in aquaculture is a mere 2 percent. Aquatic Wildlife Farming for Conservation Three significantly exploited aquatic taxa have been farmed or ranched to alleviate poaching pressures in the wild: seahorses, sea cucumbers and sturgeon. Seahorses Among ray-finned fishes, seahorses of the genus Hippocampus are among the most extensively traded, particularly in illegal markets (TRAFFIC Southeast Asia and van Asch 2013). In the global trade of wildlife, they are highly valued as dried specimens that are used as ornamental displays, curios, and most commonly in traditional Chinese medicine (TCM) (Yasue et al. 2015). At least 15 different species of Hippocampus are traded internationally, with most trade occurring within Asia but now proliferating elsewhere as well (Vincent et al. 2011). Specimens are sourced from both target and non-target fisheries, with most illegally traded seahorses coming from bycatch. There is considerable evidence that some species and populations have already been overexploited (Koldewey and Martin-Smith 2010). Seahorse farming has been developed in highcapture areas like Malaysia to lessen the dependence on wild sources (Tensen 2016). From 2005 to 2006, there were at least 28 seahorse aquaculture operations farming 13 species of Hippocampus in 15 countries (Koldewey and MartinSmith 2010). The dominant market of these farms is the sale of live seahorses for display in aquaria. The general functional approach is a small-scale intensive aquaculture system. Captive breeding of seahorses began in China and was plagued at first with problems of feeding and disease in its early stages in the 1990s. These issues have persisted until recent years, with the addition of several other challenges, such as juvenile survival and economic viability. High mortality of young seahorses has remained a bottleneck in the development of seahorse farming and this is usually attributed to poor broodstock nutrition (Planas et al. 2008, Vite-Garcia 2014). Highly unsaturated fatty acids are essential in the diet of developing seahorses (Vite-Garcia 2014, Schubert et al. 2016), which is why most feeds (usually Artemia) are enriched with these (Koldewey and Martin-Smith 2010). However, this practice is economically costly and has made seahorse farming financially prohibitive (Schubert et al. 2016). Shovelnose sturgeon Scaphirhynchus platorynchus in tank culture. Photo: Brian C. Small. Siberian sturgeon Acipenser baerii at the Mote Marine Laboratory and Aquarium in Florida, USA. Photo: Charles Weibel. A shovelnose sturgeon Scaphirhynchus platorynchus in tank culture. Photo: Brian C. Small.
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