World Aquaculture March 2019

WWW.WA S.ORG • WORLD AQUACULTURE • MARCH 2019 27 render a need for unpacking the actual potential. It turns out offshore farms are not as far or deep as perceived. We pored over all the available literature and found that, on average, offshore fish farms they are located at a minimum distance of 4.5 nautical miles from shore and extend to a depth of 27 m below the ocean surface. More importantly, we found evidence that offshore aquaculture practices can support better conditions for certain finfish and bivalve species, with no average increase in impact on the surrounding environment. While the existing evidence is not fully complete — for example, there are important missing metrics for assessing trends and few have looked at impacts other than pollution — this points to where the research needs lie to help us discover offshore aquaculture solutions and interactions. Some knowledge gaps aside, we explored the vast potential for sustainable offshore aquaculture with the data and evidence available to us. Through a combination of compiling data on hundreds of cultivated species, global ocean conditions and modelling, we found nearly every coastal country has suitable area for offshore aquaculture. Moreover, less than 1 percent of the best locations could theoretically produce over 100 million t of finfish — greater than all current wild fisheries landings combined. This means that the ‘marine footprint’ and impact of aquaculture can be significantly smaller than other animal food systems because not a lot of marine space is needed to produce a lot of food. Moreover, it means seafood does not necessarily have to conflict with other conservation objectives, for example calls to protect 30 percent of the oceans. Given offshore aquaculture is coming online now and can have sustainability benefits, this means there is a need for more research, which requires scientists, policy makers, and industry to work together. Ignoring its growth and presence is not the solution and does not best serve the environment, the people who depend on seafood, or the science to support sustainable practices. W hat will the future of seafood look like? This seemingly simple question underpins decades of research, much of which has focused on wild sources. But, as the human population balloons to 7.6 billion people, and at least 3 billion on the way by 2050, the landscape of how we produce our seafood is changing. Aquaculture plays a central role in that change and achieving a better understanding of the potential and limitations of this rapidly growing industry has set my professional course as a scientist, in particular how marine aquaculture fits into the larger puzzle of our global food system, sustainability aspirations, and conservation goals for our oceans in the future. My scientific research over the past several years has gleaned new insights into that frontier, which I hope can help lead the way forward. Part of what makes this research novel for understanding the significance of aquaculture is the big-picture approach. My colleagues and I gather as much pre-existing data and information — from species growth patterns to predicted ocean conditions in the future — that can tell us something about the potential for sustainable aquaculture at different scales and across time. So, much of what I do nowadays requires more coding and ‘big data’ than donning waders and rain gear. Here I reflect on some of the major findings from our global aquaculture research in hope that it helps move the science forward and provides new insights into how we shape the future of seafood. Possibility of Sustainable Open-ocean Aquaculture Open-ocean or offshore aquaculture is an opaque term, but an important emerging field. About sixty percent of aquaculture is freshwater and the bulk of marine production tends to occur closer to shore because of a combination of cost, technological limitations, and the biology of the species farmed. But, the putative benefits of offshore aquaculture, such as decreased conflict and increased production at a lower environmental cost compared to nearshore, A Global View of Aquaculture’s Future: A Journey of Interdisciplinary Science, Conservation and Sustainable Seafood Halley E. Froehlich Salmon farms near Tromsø Municipality, Norway (Photo: Jason Flower). Marine finfish cages in Hawaii (Photo: NOAA). ( C O N T I N U E D O N P A G E 2 8 )