As Congress begins to eye a new farm bill to replace the current 2008 legislation, some are proposing a new way to farm. Kelp farming is an increasingly attractive prospect from both an environmental and economic standpoint. Kelp is a large category of seaweed that is typically grown in cooler waters and is known for its high iodine content. Most beachgoers are familiar with large clumps of kelp that wash ashore, yet few realize that this beach “nuisance” has myriad benefits and incredible crop potential.
Kelp farming involves seeding long fishing lines and letting them stand vertically in a water column for several months. Each line can support several meters of kelp growth, and a farm could produce as much as 18-22 tons of kelp per acre each season; this enormous production could exist within a relatively small area of water.
Kelp farming is a novel concept in the United States and critics may question the value of growing such a crop. However, kelp provides many benefits. From an environmental standpoint, kelp can be farmed over a small surface area because it is grown vertically. This limits interference with aquatic life and therefore leaves a small footprint on the aquatic ecosystem. More importantly, kelp acts as a nitrogen sink: it soaks up nitrogen in the surrounding water to fuel its growth. This effect can be especially beneficial in waters with a significant amount of terrestrial runoff, as this runoff is often saturated with nitrogen from conventional land-use fertilizers. This nitrogen-sink effect effectively cleans up tidal waters and prevents dangerous algal blooms, which can form when water becomes heavily polluted with nitrogen or phosphorous. Algal blooms can destroy tidal marine life because the nitrogen rich water allows unrestricted algae growth, which sucks up and blocks out the ability of any other aquatic life to acquire oxygen. The algal blooms present an economic problem for local fisheries, which may experience a total fish kill of their desired catch.These blooms could be managed through the controlled use of nitrogen sinks like kelp farms.
Not buying kelp as a crop yet? Kelp is also being studied for its potential as a carbon sink. Plants essentially “capture” excess carbon dioxide through photosynthesis, which lowers the amount of carbon dioxide in the atmosphere. Kelp could provide a means of growing more plant matter, which could help to bind up excess carbon. This binding process reduces the amount of C02 present in the atmosphere.
Perhaps more importantly, an oceanic carbon sink like kelp could ease the production of carbonic acid in the oceans themselves. While a vocal minority questions whether or not global warming truly presents a problem, our oceans have seen a decrease in their pH since the industrial revolution, indicating increasing acidification. This process is thought to interfere with the shell-forming and bone building processes of many aquatic species, and is implicated in significant failures of shellfish and coral formation. Ocean acidification presents a problem regardless of its cause.
More interested in the economics of kelp than in its environmental benefits? Companies like E.I. Dupont de Nemours & Co have been exploring kelp as a potential biofuel. Projections suggest that kelp biofuel grown in relatively small areas could replace billions of gallons of fossil fuels. Some have suggested that offshore wind farms could act as a seeding base for harvesting a large amount of kelp, thus helping to generate both wind and biofuel alternatives at a single source, further reducing our energy footprint.
Finally kelp is a delicious treat that you should be eating. In fact there is a chance that if you are in the United States reading this right now, you have an iodine deficiency. A change in wheat farming practices combined with an avoidance of table salt are possible causes of a suspected 50% drop in iodine intake among Americans from 1971 to 2001. This author isn’t suggesting a radical increase in iodine or sea vegetable consumption, though a consultation with your doctor and some blood-work may show that kelp is a healthy, natural and delicious way to increase the amount of necessary iodine in your diet.
Written by Mike Grandy, GIELR staff