Processing Your Payment

Please do not leave this page until complete. This can take a few moments.

September 28, 2023

Offal and shells: Report says waste from seafood processing can create new revenue streams

person with wad of seaweed on boat Courtesy / Matthew Wade A new report says waste from the kelp processing industry could be repurposed for additional revenue streams.

Fish guts for compost. Mussel shells for driveway surfacing. These are a couple of the ways seafood processors are repurposing “residuals” to create additional revenue streams, rather than just dumping the materials as waste.

A new report says there’s opportunity for more growth in the residuals sector.

“We’ve been investing in our residuals for several years now,” said Luke Holden, founder and president of Luke’s Lobster in Portland. “We started with a simple plant food product, but we continue to look for additional opportunities for higher value use of the residuals we produce.”

The report, commissioned by the Seafood Economic Accelerator for Maine, or SEA Maine, examines how Maine companies are currently utilizing their residuals — and ways to reduce waste and generate more revenue from residuals in the future.

SEA Maine is an industry-led initiative that brings together leaders in Maine’s commercial fishing, aquaculture, and the marine economy.

Some residuals are already known to have significant value. For example, chitin from lobster shells is a known antibacterial, and numerous research projects are investigating its potential use for plastics and medical products.  

Lobster byproducts are used as a natural plant food. Luke’s Lobster has launched a lobster-shell plant fertilizer that provides an organic source of nitrogen, calcium, potassium and phosphorus for gardeners.

Return on investment

The seafood sector value chain collectively supports thousands of jobs and billions of dollars of revenue and output. That production also generates an estimated 57 million pounds of residuals, or waste product, annually. That’s about 25% of the total volume of seafood generated within Maine. 

Today, most residuals are disposed of as waste, but more companies use residuals to create additional revenue streams, according to the report, which examines current applications of residuals and their value as well as potential applications and value.

The report breaks down the use of residuals into three categories: highest and “best” use, “medium” use, and “low” use. 

Medium to high-value opportunities can provide revenue streams for companies while low use typically avoids waste removal cost and can include on-site use. 

Medium-value opportunities include composting and biodigestion, fertilizer and plant stimulants, fishing bait and animal feed. 

Higher-value products include pet foods and treats, pest control products, health care and medical applications, textiles and bioplastics, nutritional products and novel food ingredients.   

The study includes an online map of estimated residuals to support spatial and logistical analysis for potential residuals processing opportunities. An analysis of how other jurisdictions leverage residuals demonstrates that it’s possible to provide a 7% to 26% financial return on investment in Maine.  

“The way we use our marine resources is changing, and we now know there is value beyond what we’re currently using for many species," said Heather Johnson, commissioner of the Department of Economic and Community Development.

"Identifying specific ways in which Maine can invest in seafood residuals to leverage additional revenue, reduce waste and bring innovative products to market helps with environmental sustainability, waste reduction, and economic return for Maine businesses." 

Environmental benefit

One potential application of residuals is as a carbon sink, the report says. Bigelow Laboratory for Ocean Sciences, in East Boothbay, is collaborating with several seaweed farms to identify ways to use seaweed production residuals to reduce carbon emissions and potentially develop technologies that will allow seaweed growers to enter the carbon sequestration market.

The research involves studying different ways residuals such as kelp holdfasts — a part of the seaweed that anchors it to the sea floor — can be used as carbon sinks and/or for carbon sequestration.  

A related project is examining the potential for use of seaweed residuals as a feed for cows that causes them to burp less, reducing their methane emissions.

“Initial findings are promising and show ways the seafood industry could potentially enter the carbon offset market in addition to creating a valuable feed product that helps reduce emissions from dairy farming,” said Nichole Price, a senior research scientist at Bigelow.

Next steps include bringing together industry stakeholders to pinpoint solutions, determine the business case for operators, and address gaps in expertise, time or resources needed to develop the full potential of marine resource residuals. To get the process going, SEA Maine said it will soon launch a roadmap outlining the future of this marine sector.

The “Marine Resource Residuals in Maine” study was commissioned by the New Opportunities and Emerging Technologies subcommittee of SEA Maine and prepared by Gardner Pinfold Consultants Inc. in Halifax, Nova Scotia.

The subcommittee mandate is to identify opportunities to increase value-added products, strengthen infrastructure, and maximize efficiencies across the seafood value-chain to grow commercialization, business development and jobs. 

To view the full report, click here.

Sign up for Enews


Order a PDF