Unmade decisions can turn bioresources into waste

Companies often seek new uses for agricultural and fishing by-products only when external pressure forces them to, rather than as part of a considered business strategy, ERR reports. Kristiina Kerge, a circular bioeconomy doctoral student at the Estonian University of Life Sciences, says management decisions help determine whether these resources are put to use or treated as waste.

Each year, the European Union imports tens of millions of tonnes of organic raw materials even as large volumes of by-products emerge from local agriculture, forestry and fisheries. In 2022, those sectors generated 22.3 million tonnes of officially recorded waste in the EU. Studies indicate that bioresources produced as by-products and not classified as waste amount to several times more.

In 2025, organic materials, including animal and plant by-products, were the EU’s largest category of imported recyclable raw materials: 30 million tonnes, or 60.3% of total imports. Waste made up only 3.2% of organic material imports.

Up to 35% of global fisheries and aquaculture production is lost each year, according to estimates by the UN Food and Agriculture Organization. The fate of that share is not known: it may be classified as waste or used as a by-product to make animal feed. The same fish can become food, feed, oil, an input for fertiliser or waste, Kerge writes. The material itself does not determine which outcome follows.

Kerge’s doctoral research focuses not on the technology used to turn manure into biogas or fish remains into feed, but on how businesses decide whether by-product bioresources remain economically visible and gain a new use, or are sent for disposal.

As part of the international CIRCLE project, researchers collected 150 circular economy practices from companies in Estonia, Latvia, Lithuania, Norway and Ukraine. In an initial analysis, companies did not necessarily view their residues as waste, but as raw materials for use within their own operations or as inputs for other production. Examples included making fishmeal and fish oil from fish-processing residues, producing energy and fertiliser from manure, turning wood residues into fuel, and using plant by-products to make new products.

A more detailed analysis, however, found that the companies generally lacked formal internal procedures for regularly assessing bioresource by-products.