In my last post, I discussed the largest source of fishmeal and fish oil globally, reduction fisheries (if you didn’t get a chance to read it, catch up here!). Reduction fisheries have been the primary source of fishmeal and fish oil since at least the late 1950s. In this article I’m going to give an introduction to three (mainly) distinct other sources of fishmeal and fish oil. These are important to consider as not all sources of fishmeal are of an equal quality (for when the products are used, such as lower protein content or a lack of some important amino acids), or of equal environmental and ecological impact. This second point is much more nuanced and will be the subject of many future posts, but I’ll give an introduction to some of the considerations here. The four main distinct sources are: reduction fisheries, by-products of human consumption fisheries, by-catch of human consumption fisheries, and biomass fishing.
- Reduction Fisheries
Reduction fisheries are fisheries for the dedicated purpose of landing fish for the production of fishmeal and fish oil. They are the largest producers of fishmeal and fish oil globally (65% of global production according to the UN’s Food and Agriculture Organization; FAO 2014), and are also some of the largest fisheries globally including Peruvian anchoveta and Atlantic herring. These fisheries set out to target specific fish for their characteristics and the resulting quality of fishmeal and fish oil they can produce. As these fisheries generally catch only their target species (with small amounts of other by-catch), they can be managed as individually which distinguishes them from two other sources described below.
Fishmeal is often made from the processing by-products of direct human consumption fisheries and, according to the Food and Agriculture Organization, accounted for 35% of fishmeal production in 2012. This is a huge increase from recent years and predictions are that fishmeal from by-products will surpass fishmeal from reduction fisheries over the next 50 years. These products come from using the parts of the fish that humans often do not eat. Once the desired part of the fish is removed (often the fillet, other muscle tissue, or roe for herring and sturgeon fisheries), the remaining portion (often called trimmings, carcasses, or by-products) is processed
into fishmeal. The amount of fishmeal produced from these by-products (historically mainly derived from ‘whitefish’ including Atlantic cod, pollock, and hake) is less than the yield when whole fish from reduction fisheries are used, and the resulting fishmeal is often of a lower protein content and lower quality of amino acids present.
Recently, there has been a developing body of work to quantify the environmental and ecological impacts of fisheries and aquaculture such as in ecological footprint analysis or live cycle assessment. When accounting for the environmental and ecological impacts of using these by-products, there is a debate over whether these products are inherently ‘free’ because they are not the main purpose of these fisheries and they would theoretically go to ‘waste’ after. However, this ignores the physical reality that energy was expended by the fish (or other organism) to grow these parts that humans have decided are undesirable, and that the catching and transporting of this mass requires the same amount of energy regardless of the value to the fishers. The ‘by-products’ therefore cost energy to acquire, but also represent usable energy in the form of potential food or feed products. They therefore share the environmental and ecological costs associated with their source fisheries, which becomes important when comparing different sources of fishmeal and fish oil.
By-catch is often caught along with the targeted species in fisheries, and the use of this catch is mixed. Some by-catch, often being low-value catch, is discarded back into the water with a fairly high likelihood of mortality. However, some by-catch is landed due to economic value or legal requirements. Norway, for instance, requires all by-catch to be landed in its no discard policy for its fisheries. Much of this by-catch that is not marketable for human consumption is sold to fishmeal factories. Under this system, fishers are incentivized to reduce their by-catch as it is less valuable than their target species, but they are also effectively subsidized for landing fish with no market value for human consumption. While this system reduces by-catch and increases transparency of by-catch and discards, the effect of harvesting individuals that may have survived being discarded has not been fully examined. The major source of fishmeal from by-catch is from shrimp fisheries in Southeast Asia and China where all the catch is landed but only a small fraction was targeted shrimp. The majority of the catch is sold for fishmeal production.
- Biomass fishing
The distinction between using by-catch for fishmeal production, and biomass fishing is the lack of a target species. Biomass fishing occurs mainly because the former target species (in highly non-selective fisheries like shrimp trawling) is now present in such a low abundance, that there is no incentive to sort through the catch for the former target species, and there is an option of selling all of the catch to fishmeal producers. This non-selective fishing thus becomes for ‘fish’ biomass as a source of protein. This raises concerns separate from reduction fisheries as reduction fisheries intend to target 1 or possibly 2 species whose populations can be managed in fisheries stock assessments. However, targeting all species that can be caught by a bottom trawl fishery means that no species or population is being managed individually and that some are likely to have their populations depleted at a faster rate than others. Many of these concerns apply to sourcing fishmeal from by-catch, as the non-target species populations are often not being managed.
While these forms of sourcing inputs for fishmeal production are fairly distinct, there is obviously some overlap. By-catch and biomass fishing sources both rely on non-targeted species to a certain extent, in that they are not the target species. Some consider by-catch to be the by-product of fishing where the method is not 100% selective for the target species, which encompasses most fishing methods (more to come on gear and gear selectivity in future posts!). While by-products have been playing a larger role in global fishmeal production, some of my current research will uncover more on the large role of by-catch and biomass fishing in Southeast Asia and China, which until now has not been distinguished completely from by-products. It is important for researchers to distinguish these different sources of fishmeal as they each have their own costs and benefits associated with them. This is part of my work, and what I will delve into deeper here.