19 Jan 2024 --- A marine food production systems study reveals an alarming trend where the global number of fishers has steadily risen since the 1990s despite considerable technological advancements. Led by researchers from the University of Bergen, Norway, the results indicate a decline in productivity per labor unit in the fishing sector, specifically fish per fisher, which can have extensive consequences for food production efficiency, marine ecosystems and fishing communities.
“That the ocean provides us with less fish despite the fact that we spend more energy on catching it is concerning and indicates that many fisheries worldwide are being overfished,” Kim Scherrer, a postdoctoral researcher at the University of Bergen and corresponding author of the study, tells Nutrition Insight.
“Overfishing undermines the resilience of food production in fisheries. Overfished fish stocks have a much lower capacity to contribute to global food security in the event of a climate shock or food emergency than well-managed fisheries do.”
“They are also much more vulnerable to shocks. Keeping fish stocks healthy and abundant through good management, on the other hand, creates a natural ‘storage’ of large amounts of nutritious fish. This is a great side effect of effective fisheries management, both for our food security and for the resilience of marine ecosystems.”

Late last year, the World Wildlife Fund US launched its landmark Oceans Futures platform, which pinpoints the global seascapes forecasted to experience climate-driven fisheries migration, potentially resulting in conflict, nutrition and food insecurity. The system provides early warning signals, allowing authorities to take conservation action and prevent conflict.
Buttoning up fisheries management
The current research findings, published in Nature Sustainability, detail significant labor challenges in marine food production systems and analyze changes in the activity of the numbers of fishers from 1950 to 2015.
The increases are mainly visible in low and middle-income countries, while there has been a steep decline in high-income countries. The trend has reduced catch per fisher compared to the rapid growth of food production per farmer.
The research findings are valuable for policymakers and stakeholders in fisheries and environmental management. The researchers highlight the need for a balanced approach to resource management and technological advancement in this sector.
“Generally, policymakers need to make sure that the combination of inputs in a fishery — like fishing boats, fuel, fishing time and labor — are adjusted so that the amount of fish caught annually is sustainable in the long run,” Scherrer stresses.
“Acknowledging that there’s an upper limit on the sustainable catch in every fishery, the political decisions should come down to how the amount should be caught.”
Working closely with stakeholders to find solutions is crucial to working around current trade-offs. “If the priority is to maintain high employment, the fishing technology and fishing time per person might have to be reduced,” she says.
“If the goal is high efficiency, the number of fishers will have to be reduced. We see indications of such priorities in our data. High-income countries, for example, have had declining fisher numbers throughout the period, but in return maintained a high labor productivity.”
“A concrete measure is to remove subsidies that contribute to overfishing. We find it concerning that capacity-enhancing subsidies, which amount to about 20% of the value of global catches, are being given to a food industry with declining production both per laborer and per unit energy,” Scherrer explains.
The actual cost of overfishingPoor marine resource management is threatening the resilience of food production in fisheries.
The current research expands on previous global fishing estimations by delving into how projections have changed between 1950 and 2015.
“We find that the number of fishers formally employed in fisheries grew globally in the period. The trend varies between countries, and in high-income countries, the number of fishers has instead decreased continuously,” says Scherrer.
A significant part of the trends being observed are in overfishing. “Overfishing is a large food security concern since it reduces the amount of seafood available in the long run. Fish and many other blue foods are both nutritious and have a relatively low carbon footprint, and therefore, have a role to play in achieving healthy and sustainable diets.
“When fish stocks are overexploited, their contribution to food security and nutrition is undermined.”
The researchers are convinced that reformed and strengthened fisheries management is the key to addressing overfishing and the consequent decline in labor productivity that it causes. Furthermore, previous studies have found that countries with higher-quality governance have less overfishing.
“We found that countries with strong governance systems and low corruption had higher catch per fisher. A high GDP per capita was not sufficient, indicating that good governance is more important than economic conditions,” she says.
Labor productivity projections
Wild-capture fisheries data showed striking trends in labor productivity. While the food production per agriculture worker increased by about 70% from 1990 to 2015 — and production per fish farmer grew slightly — the catch per fisher decreased by about 30%.
Scherrer notes: “This trend is driven by a combination of decreasing catches and growing fisher numbers, especially in middle-income countries. Here, especially, it seems like too many fishers have been chasing too few fish recently. This finding indicates very different performance for marine and terrestrial food production systems.”
The differences in performance should be considered in context with other food systems. The amount of fish “produced” annually in wild-capture fisheries depends on the natural ecosystem, unlike agriculture and aquaculture, where the production relies on added fertilizers, water, feeds and pesticides.
“Therefore, we expect fish catches to stagnate much earlier than other food production. But since excess fishing effort and labor in fisheries can cause overfishing, it is important to keep track of how these different “inputs” to marine food production evolve,” Scherrer explains.
Meanwhile, the latest climate model projections identifying the drivers for non-uniform Indian and Arabian ocean warming could facilitate better marine resource management. However, researchers warn that nutrient deficits could sweep across regions highly dependent on fish for daily survival.
By Inga de Jong