By April Forristall, SeafoodSource assistant editor
Published on 04 December, 2011
The majority of fish waste is turned into fishmeal or fish oil. But what if there was a way for processors to earn three to four times more money from selling their fish waste?
Gurry Investments, a Boston-based investment firm established in 2000, is using its technology to produce organic fertilizer using waste from farmed fish. The company, working with fertilizer producer Multi Bloom and Mega Green, which is owned by Consolidated Catfish of Isola, Miss., uses a hydrolysis process. The skin and bones are removed from filleted fish, leaving the protein. The offal is ground into a slurry form, processed and separated in a three-stage centuefuge. The result is a product with 10 percent high quality fish oil and 4 percent sediment, which is used as ground cover, hydrolysate or organic fertilizer.
According to Carl Reetz, president of Gurry Investments, using fish waste for organic fertilizer instead of fishmeal or fish oil can benefit both processors and the seafood industry as a whole.
“The profits of organic fertilizer are three to four times more than from fishmeal. It costs USD 1.60 to produce a gallon [of organic fertilizer], which can be sold wholesale for USD 6 to USD 8 per gallon and sold retail for USD 20 per gallon,” said Reetz.
For processors, this means they can get more than double the price for their fish waste than they would selling it for fishmeal or fish oil.
“A ton of fish meal may sell for USD 900 to USD 1,300 per ton depending on market prices, which means 1 pound of fish offal is worth USD 0.15 to USD 0.22 each. Organic fertilizer will sell for USD 6 to USD 8 per gallon, meaning each pound of fish offal is worth USD 0.60 to 0.80 per pound,” said Reetz.
Gurry Investments is currently using farmed catfish and salmon but is exploring the use of other species, including tilapia.
“Missisippi State University tested our product against others, and it showed to have superior growth and better color on plants and flowers. The University of Massachusetts Amherst showed the nitrogen in our organic fertilizers was slow release that will benefit crops over a 15-week period. [With] other fertilizers the nitrogen is used up in three weeks,” said Reetz. “The University of Wisconsin Madison showed our organic fertilizer, when applied to grazing land, a 20 percent gain in weight [in dairy and feed cattle].”
By marrying the seafood and agriculture industries, using fish waste to produce fertilizer opens new markets. The organic fertilizer can be sold to commercial growers of soybeans, potatoes, corn and wheat and to retail businesses such as golf courses and lawn and garden centers.