Interpreting “Blue Loss” and Measuring the Hidden Animals in Our Food System
EXECUTIVE SUMMARY
This report examines the issue of “blue loss,” or how many aquatic animals are unaccounted for in the human food chain each year. Aquaculture is often touted as the solution to overfishing, yet our study has found that up to half of all animals caught at sea are fed to fish on farms. This poses serious questions about aquaculture’s animal welfare paradigm. Listed below are our main findings:
● Approximately 1.2 trillion aquatic animals are fed to other aquatic animals each year. This is approximately one-third to one-half of all animals fished.
● In order to produce the billions of fish that end up on the human plate, trillions of fish are processed, or fed live, as fish feed.
● Many of the fish we feed Salmon have similar welfare needs, thus creating a ‘welfare pyramid’ effect, as each farmed salmon must eat the biomass equivalent to 9 herring, or 120 anchovies, to be brought to harvest weight.
● In terms of welfare, this means that each farmed fish we produce under welfare scrutiny carries with it a vast amount of welfare issues that are invisible to the consumer.
● Possible interventions include several market developments that have the potential to severely disrupt the industry. Plant-based fish feeds could remove trillions of animals from the food system.
INTRODUCTION
The purpose of this paper is to provide a primitive estimate for the number of caught fish which are killed in order to be fed to farmed fish. These animals, which are used in the production of human food but are not used for direct human consumption (DHC), are hidden from view in the supply chain. The method outlined below produces the estimate that around 1.2 trillion aquatic animals constitute the ‘blue loss’ every year.
Estimates for total fish caught vary, with Fishcount’s Alison Mood providing a range between 0.97-2.74 trillion. The comparison heuristic between these estimates is limited, because this paper’s model includes several industry practices that Mood does not (i.e. bycatch, discard, live feed), but if our estimate is close to the true value, up to a third of all caught fish could be fed, directly or indirectly, to other animals.
The sheer scale of this issue is remarkable. It would mean ten times more fish are used as feed than Compassion in World Farming estimates are farmed for DHC every year. This number of blue loss fish would be 17 times more than the number of the terrestrial animals farmed annually around the globe. Even if this estimate is wrong by an order of magnitude, the number of animals in the invisible blue loss category could be greater than DHC animals currently receiving attention from animal advocacy campaigns.
The majority of caught fish which are not eaten directly by humans are fed to farmed fish. Teleost fish, such as Atlantic salmon, are the only obligate carnivores that we farm at any scale, and due to current cost and nutritional factors, fish products are an essential part of their diet. Much of the rest ends up in the food chain, either as terrestrial animal feed, or fertilizer.
Many of the fish we feed Salmon are in the same infraclass, meaning they have similar welfare needs. This creates a ‘welfare pyramid’ effect, as each farmed salmon must eat the biomass equivalent to 9 herring, 4 or 120 anchovies, to be brought to harvest weight. These secondary and tertiary fish are similar in biology to the salmon crop, but because they are caught rather than farmed, their welfare is held to a much lower standard. This calculation shows that, In order to produce the billions of fish that end up on the human plate, trillions of fish are processed, or fed live, as fish feed. The reality is that each farmed fish we produce under welfare scrutiny carries with it a vast amount of welfare issues that are invisible to the consumer.
This estimate makes the best use of the scarce data available, and the reader should assume the margin for error is very large.
Every effort has been made to annotate the model used.
