Fish waste gets new use — Compost project sees early growth

Photo courtesy of Matti’s Farm. Matti’s Farm volunteers create windrows of compost, made of mixing fish waste and wood chips.

Photo courtesy of Matti’s Farm. Matti’s Farm volunteers create windrows of compost, made of mixing fish waste and wood chips.

By Joseph Robertia

Redoubt Reporter

When it comes to problems, there are often two responses — complaining or doing something to solve them. Blair Martin is the latter type, and decided that something had to be done with all the fish waste generated from the Kenai River personal-use dip-net fishery.

“It first came to my attention here at the resort,” he said, referring to the Diamond M Ranch Resort, operated by the Martin family, where tourists rent lodging or RV space during the summer fishing season. Being just a few miles from the Kenai River, many guests bring their catches back to the resort to fillet them there.

“I saw huge amounts of dip-net waste going into our Dumpsters,” he said.

In the tourism offseason, the Martins also are building Matti’s Farm, a nonprofit named in memory of their son, Matthias, who died in 2009. The goal of the organization is to get kids involved with the farming lifestyle, encourage and support sustainable agricultural practices and teach resource development skills. It occurred to Martin that finding a use for the fish waste, turning it into agricultural compost, would fit right in with the mission of Matti’s Farm.

“It was clean, natural and an asset to gardening, so it didn’t seem like something we should be wasting in the landfill,” he said.

The fish waste, being rich in nitrogen, served as a great base ingredient for compost. It need only be paired with a carbon-based ingredient, such as sawdust, fine wood chips, cardboard, hay or peat moss.

Martin wanted to do more than compost on a small scale, though. During and after the dip-net fishery, the Kenai beaches are lined with thousands of pounds of waste in the form of salmon heads, skinned carcasses, guts and eggs, as well as carcasses of by-catch, such as flounder and dogfish.

Martin and the other Matti’s Farm board members began exploring ideas for where to compost on a larger scale, and searching for a large volume source of carbon materials. They found both at the same location in Nikiski, where much of the lumber work was done for home construction by Hall Quality Builders.

“There were 3 acres of wood chips and sawdust of an indefinite depth, and with composting requiring a ratio of eight to one carbon to nitrogen, it made sense to bring the fish waste there,” Martin said.

With a composting site secured, Martin turned his attention to where and how to collect the fish waste for the project. The more people he talked to about the project, the more people were in favor of supporting it, he said.

He worked with Kenai city officials and members of the Respect Our Kenai organization — a youth-sponsored volunteer group devoted to keeping the beaches clean during the dip-net fishery — to get a Dumpster put on the north beach of the river, at the Spruce Street access point, which is a major hub for traffic to and from the dip-net fishery.

“Unfortunately, the Dumpster brought in basically zero carcasses,” Martin said.

Due to a huge sockeye return this year, the dip-net fishery was open 24 hours a day, which did not allow for the city to use its two tractors to drag the beach at night, raking the carcasses into piles that could have been put into the Dumpster.

Adding to the situation, a fecal coliform bacteria surge in the river just prior to the fishery’s opening resulted in the city instituting a rule that dip-netters throw their carcasses into fast-flowing water. The dip-net fishery this year also coincided with some of the largest high tides of the year, which further removed carcasses from the beach.

So Martin turned to area fish processors and fish oil extractors, both of which can also generate a tremendous amount of fish waste. He found several willing to part with heads and carcasses, as well as liquid and cooked fish waste, the latter of which is comparable to the consistency of oatmeal.

On site, the fish waste was pulverized and mixed with the sawdust by heavy equipment to form long lines referred to as windrows, rather than piles in which moisture and temperature management can be more difficult.

“Windrows are much more efficient and easier to churn than piles,” Martin said. “It aerates it better to give oxygen to the microbes breaking down the materials. The temperature will just explode to 140 degrees within 36 hours.”

Also, Martin explained that, since the composting is occurring under aerobic conditions, the main gas generated is odorless carbon dioxide, rather than methane and hydrogen sulphide, which can occur under normal anaerobic conditions and cause a more pungent, decaying smell.

“Once it’s churned, it has almost no smell, so it’s not enticing to bears or gulls or other critters. We haven’t even seen any animal tracks out there,” Martin said. “Within three to four weeks, it’s pretty tight-knit. We’ve got an acre right now that’s 2 feet deep and ready to be bagged.”

But this packaging process is still a long way off, as Matti’s Farm board members are pursuing funding for screening and bagging equipment to hopefully market their product in 40-pound bags, possibly as far away as the Lower 48 gardening market.

In the meantime, they are hoping to serve local farmers and gardeners looking to offset soils that are traditionally acidic and low in nutrients, as well as improving vegetables growing locally so as to reduce the need for importing increasingly expensive produce from the Lower 48.

“We can sell it by the pickup load right now,” Martin said. “And a lot of farmers currently import a similar product at around $300 a yard retail, but I think we can be more competitive than that and with a superior product.”

To learn more about the fish waste composting project, visit the Matti’s Farm page on Facebook at


1 Comment

Filed under dipnetting, gardening, Kenai

One response to “Fish waste gets new use — Compost project sees early growth

  1. Shana Loshbaugh

    This sounds like a great idea. Hope it flies! Kudos to the Martins for their community service and constructive ideas.

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