It’s April already! We are well into Spring now; if you’re in the big city of Washington, D.C. it’s the season for cherry blossoms, and if you’re with us on the eastern shore, we’re in the season of Maryland’s state fish, Striped Bass! (Stay tuned next month for more on this neat fish.)
This month, we’re wrapping up our series on the four major types of aquaculture with Offshore Cage/Sea Farming. You may have also heard this referred to as some variant of “Open System Aquaculture” or “Open Ocean Aquaculture.” Picking apart its many names we can guess that the defining feature of this system involves some variety of ‘cage’ out in the open ocean for farming fish.
These open ocean systems are considered a fairly new method in the field of aquaculture, the concept having emerged only within the past century (depending how you decide the “beginning” of something, many sources credit the Vik brothers from Norway as “the first to do so” in 1959).
So why do we produce fish offshore? One of the biggest factors is that demand for seafood continues to grow and we will eventually run out of land. Offshore Sea Farming has plenty of space to expand out in the ocean and it can match the population’s demand for seafood more easily and sustainably than other aquaculture methods. This is because any farm situated inshore is limited not only by the space for its infrastructure but by the amount of pollution their fish cages produce. That is to say, if an inshore farm has too many fish, the waste produced by those fish will pollute the environment, making it uninhabitable for the fish that produced the waste in the first place, in addition to all the other animals that share those waters.
Further out in the ocean however, that pollution is diffused because the farm is in open water which carries the waste away. Thus, if consumers want more fish, an offshore farm can increase the number of fish in their system, without heavily impacting the environment. The hope for this method is that it will open up a path for us to produce more seafood of our own—as it currently stands in America, about 65% of what we eat is still imported from other countries.
Of course, the question then becomes how much waste can the ocean handle? Will our demand eventually exceed even the capacity of the oceans themselves? Considering this method is so new, there are concerns that our current method is shortsighted.
Fish escapes from cages will always occur with any sort of aquaculture system in natural bodies of water. With Offshore Sea Farming, escapes are more likely than for Nearshore Farms due to the turbulent environment—the further offshore you raise your cages, the more uncontrollable variables you face: large ocean waves during storms are tough on cages and it’s harder to regulate temperature. Not being able to monitor the cages as closely, to watch for damage to the cages or other problems, results in a higher likelihood of fish escape.
On top of the cages being more susceptible to damage, the further away from the shore you get, the bigger the predator that wants to get into your cages. For nearshore farmers, birds are extremely persistent, otters and snakes can be an annoyance, and even raccoons can be a problem. For open ocean farmers, a concern is sharks. And there are very few ways to discourage sharks other than hoping your fish cage is strong enough that they’ll eventually give up and go away.
Offshore Sea Farming is also quite an initial expense for the farmer. Since it is far offshore, in open water, the equipment has to last a long time without needing to be brought inshore for service. While it is currently not a standard in the industry, some research suggests that for this type of farming to remain economically sustainable in the future, farmers should invest in structured spaces out in the open ocean alongside the farm itself for handling, sorting, harvesting, and equipment maintenance and even repair.
Unlike our previously discussed aquaculture RAS (Recirculating Aquaculture System), which promises to eventually come to Maryland, it is unlikely that open ocean aquaculture will have an immediate impact for those on Maryland’s Eastern Shore. Currently, most Open Ocean Aquaculture for the US is happening in the Gulf of Mexico. At the moment, there are no plans for Open Ocean Aquaculture in the mid-Atlantic region, as aquaculture in this area is managed by the states, as opposed to at a federal level. Because our current aquaculture consists mostly of Inshore/Nearshore farming, there is worry that too much farm infrastructure offshore would bring waste to Maryland’s current inshore farms.
This wraps up our brief overview on the four major types of aquaculture. The field is constantly and quickly changing, so it will be interesting to see what technology comes up in the future. See you next month where we focus on hybrid Striped Bass.