The global population is today estimated to be 6.5 billion, and is expected to reach 10 billion before it (hopefully) crests near mid-century. While population is increasing, arable land is decreasing due to soil salinization, erosion, poorly-planned development (i.e. urban sprawl), dam-building, and desertification. Genetically-modified foods may help touch off a second “Green Revolution“, but that may not even be enough (see my writeup on Vertical Farming for more). That’s where aquaculture comes in.
The Beginnings of the Blue Revolution
Introduced in the late 1960s and early 1970s, salmon aquaculture today produces greater tonnages of salmon a year than wild catches. Just go to the grocery store and you’ll find farm-raised salmon for about $5 per poound (on sale) while wild salmon hovers near $10-14 (at least in my area, this may be significantly different if you live near major fish ports). Though some folks claim that there’s a significant difference between the two types of salmon, it’s just likely to be positive attribution error, or simply that wild-caught salmon is more carefully prepared. Either way, many consumers, including myself, find the farm-raised salmon to be an excellent way to add salmon to their diets.
Critics of the methods of industrialized salmon farming have been many and varied. Among the criticisms leveled against it are that it spawns algal blooms due to the nitrogen content in the concentrated fish waste, that it leads to interbreeding between farmed and wild stocks–thus reducing the genetic variability of wild stocks and increasing their susceptibility to mass disease–, and that it destroys crucial shallow estuarine ecosystems by virtue of the fact that farming salmon is easiest near shore. These criticisms have paradoxically led to either one of two decisions if you are eco-conscious: 1) eat much less fish that is wild-caught from only the most carefully managed fish stocks ($$$$), or 2) don’t eat fish. For those of us without the $$$$ and that like fish, we are stuck with a poorly-regulated, dirty, destructive source of this occasional delicacy.
Like most frustrating aspects of environmental protection, aquaculture is not going to disappear, in fact given the reasons I discussed above it is likely only to intensify. In an excellent and lengthy article in today’s NYTimes Magazine, Paul Greenberg discusses what may take aquaculture from big niche industry to big business: Cod Farming. Once thought so abundant that no amount of fishing could decrease their yields, Cod fueled the growth and prosperity of colonial America, and much of the shipping and fishing fleets of Atlantic Europe. But of course, “they” were wrong and Cod stocks plummeted to un-fishable levels in the 1980s and 1990s. Cod farming may help to change all that by reducing pressure on the wild stocks and by helping to re-energize recently destitute stretches of northern coastlines.
But farming Cod is a tricky business–far trickier than salmon. To reach profitability, farmers have had to overcome a host of obstacles including cannibalization, premature sexual maturity, and low survival rates that plagued early efforts. The article describes these obstacles and how they may be overcome. The bottom line is that large-scale commercial cod farming may become a reality in the next decade. And, of course, cod is just the first foray into farming the bulk of ocean fish species. Tuna, swordfish, and host of others are next.
Developing the Oceans
The oceans are big: they are much, much bigger than the territorial waters of sovereign nations. Offshore aquaculture is going to happen because of the enormous force of a steadily-growing and ever-more-rich world population. Near-shore waters suffer from the problem that most of them are vulnerable to weather. However, vast tracts of the ocean experience virtually no rain and never see hurricanes. Those same tracts happen to occupy what is now the harshest desert environment on the planet. A measure of the “fertility” of the world’s surface is its Net Primary Productivity, or the rate at which photosynthesis occurs. The map above shows high NPP in red while low areas are in blue. Because of map projection effects, the size of high latitudes is, as always, exxagerated. Thus, most of the world’s oceans are “blue” productivity areas. Will off-shore aquaculture help bring life to these marine deserts?
The Millenial Project
One of the most exciting books I’ve read in the last decade is The Millenial Project by Marshall T. Savage. It’s subtitled “Colonizing the Galaxy in Eight Easy Steps.” The second step, called Aquarius (the first step being the constitution of the First Millenial Foundation, which is now called the Living Universe Foundation, also see the Wikipedia entry) involves the creation of floating cities in the marine deserts. These cities would use massive Ocean Thermal Energy Conversion (OTEC) generators to produce energy for a mass colonization of the world’s oceans. Those cities would use aquaculture to produce food, sustained by the elemental nutrients brought up from the depths by the OTECs.
The Millenial Project is an exciting read because it’s a grand and coherent vision of a possible future direction of our species. And, it relies on the Earth’s oceans to help drive our progress to the stars. The book was written back in 1992 but remains entirely relevant today. That’s not to say it doesn’t have some major difficulties: a manned mission to Mars looks easy by comparison. But nevertheless, such a bold vision of our future can provide insight into the inevitably more moderate reality that will come to pass. Savage’s main contribution as I see it is his ideas of using the oceans to stave off what seems to me an inevitable Malthusian crisis.
Aquaculture is nothing new in human societies, but its widespread use to provide significant proportions of the world’s caloric needs is. Cod farming represents the next major step in that direction; the end result may be something like Savage’s Aquarius. Isolated settlements of farmers may form much like oil rigs. At first, those farmers would rotate, but eventually–and especially if security for these places could be assured outside of territorial waters–whole families and communities could grow up around offshore aquaculture. So, read the NYTimes Magazine article (free subscription required), and check out Savage’s book. You won’t be disappointed.
Skimmed through it, was disappointed. Too Utopian, too “new-agey” and too techno-transcendental.
Babbler,
Which were you disappointed by, my article, or The Millenial Project? I’m just kidding, I assume you mean TMP. It was definitely Utopian, though I wouldn’t say “new-agey”, with the exception of the whole Spirulina algae thing. And, as far as techno-transcendental goes, that’s kind of my bag.
What I most enjoyed about his vision of Aquarius was the idea of forming cities around people instead of around industry, agriculture, or commerce as they are designed now. I know very little about urban design, but most US cities are unpleasant places to be, let alone live. I can only imagine how interesting it would be to live in somewhere designed to make humans comfortable and productive.
I said I only skimmed through it. The biggest problem with it, to me, was probably the same thing that attracted you: it was visionary. Also, I obtained my copy at a used book store, so I had the insight of hindsight with me. I look through the glossy pictures and colourful descriptions, then at the practical achievements made, and I just shake my head.
This is of-topic question (if I can ask), but it been bugging me what is a better blog hosting service: blogspot or wordpress. Because I cannot decide.
Paul Molyneaux, award winning journalist and author, has written a new book: “Swimming in Circles: Aquaculture and the End of Wild Oceans,” which looks at fish and shrimp farming within the contexts of economics, seafood supplies, wild fisheries, and traditional fishing culture.
In his book Molyneaux makes the case that current aquaculture development policy is similar to the fisheries policy that preceeded it. Aquaculture is no solution, it is a high tech substitute for the degraded natural production system. In the end it will accelerate the decline of the marine environment.