January 27, 2017 — The following is excerpted from an article by Emily Liljestrand, a master’s student in the University System of Maryland’s Marine Estuarine Environmental Sciences program. It was published Tuesday by Maryland Sea Grant:
Atlantic menhaden, though completely unpalatable to all but the most desperate diners, can be found in many commercial products. They are processed into omega-3, fatty-acid-rich nutritional supplements as well as aquaculture feed and fertilizer. People have utilized them for hundreds of years. The name “menhaden” even comes from the Native American word “munnawhatteaug,” which means “that which fertilizes.”
To get from this one-foot-long, oily, bug-eyed creature to the myriad of products we use them for requires several steps of fishing and processing. Most of which we got to witness first-hand on our trip to Reedville.
We were welcomed by the Omega Protein staff who guided us to a cozy conference room where we watched a video that demonstrated the fishing operation. Delightful as it might have been, having nine students and faculty go out on a fishing vessel that can often spend days offshore is a bit impractical.
But in the video we got to see the whole fishing process. Spotter planes take off across the Chesapeake Bay and nearshore Atlantic waters, looking for the telltale sign of a menhaden school – darkened bubbling waters where menhaden were being targeted by predatory fish and sea birds. Pilots can estimate with a high degree of accuracy not only the size of a school but also the average size of menhaden within that school.
The fishing vessel charges onto the scene and once in position, deploys two smaller seine boats that together use a single net to rope up as much of the school as they can. Once the bottom “purse string” gets pulled, it’s only a matter of hauling everything up onto the larger vessel and/or vacuuming menhaden into the hold. If done efficiently, the whole process may take no longer than half an hour.
Our guided tour around the on-shore facility in Reedville showed us how the processing continues onshore. The school of menhaden (or multiple schools, collected over several days) are deposited into a large holding vat and cooked at extreme temperatures. This procedure breaks down the fish and creates a sort of menhaden “slurry.” Through a series of heating, cooling, and further chemical processing, the lighter liquid oil gets separated from the harder, denser meal.
Omega Protein told us about its efforts to make its processing operations sustainable. It uses recycled/reclaimed water extracted from the menhaden themselves as a cooling agent, which has saved about 18 million gallons of water annually, and safely disposes of nitrogen byproducts. Omega’s fossil fuel consumption has dropped by 80 percent since 2012 thanks to several plant renovations.