Reveal the environmental impact of Nile tilapia farming by harvest weight

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By Milthon Lujan

Tilapia farming cage. Source: UNAL Agency.
Tilapia farming cage. Source: UNAL Agency.

Nile tilapia is a popular and versatile fish, making it a cornerstone of aquaculture. But how does harvest size impact the environmental footprint of tilapia production? A new study sheds light on this important question.


Researchers from the Federal University of Bahia (UFBA) and the Federal University of Maranhão (UFMA) assessed the energy and environmental performance throughout the life cycle of Nile tilapia production for harvest at different weights.

Weight Matters: Smaller Fish, Lower Environmental Impact

Researchers employed the Life Cycle Assessment (LCA) technique to analyze a product’s environmental footprint throughout its life cycle. LCA is a powerful tool for evaluating the environmental impact of a product from “cradle to grave.”

The researchers evaluated the environmental impact of producing 1 ton of Nile tilapia harvested at various weights: 0.6 kg (1.32 lb) to 2.0 kg (4.4 lb). They analyzed the entire life cycle, from fingerling production to adult fattening in cages. They assessed various environmental factors, including:

  • Land use
  • Water consumption
  • Energy use
  • Global warming potential
  • Acidification
  • Eutrophication (nutrient pollution)

Surprisingly, researchers found that smaller fish tend to have a lower environmental footprint in several key areas.

Why Smaller Fish Have a Lower Impact

Smaller Nile tilapia have a better feed conversion rate, meaning they require less feed to reach their target weight. This translates to a lower environmental footprint because feed production contributes significantly to the overall impact.

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Here’s why:

  • Feed Conversion: Smaller fish require less feed to reach their target weight compared to larger fish. This results in lower energy consumption in feed production, which greatly contributes to the environmental impact of tilapia farming.

Breakdown of Environmental Impact

The study evaluated factors such as land use, water consumption, energy demand, and greenhouse gas emissions. While raising smaller fish required more fingerlings (young fish) to reach the final goal of 1 ton, the overall environmental impact was lower due to the improvement in feed conversion rate.

Key Contributors to Environmental Impact


The research identified the main culprits of the environmental footprint of tilapia production:

  • Feed production: This stage consumes the most energy and resources, highlighting the importance of sustainable feed ingredients and efficient production practices.
  • Rearing and fattening: These stages contribute more to acidification and eutrophication (nutrient pollution) of water bodies. Optimizing these processes can minimize this impact.

Strategies for Sustainable Tilapia Farming

The study points out several strategies to reduce the environmental footprint of Nile tilapia production:

  • Sustainable feed ingredients: Sourcing feeds from ecological sources can significantly reduce environmental impact.
  • Improved feed conversion: Optimizing feeding practices to minimize waste can make a big difference.
  • Control of feed loss: Preventing unconsumed feed from entering the water reduces nutrient pollution.
  • Treatment of production effluents: Proper management of fish farm wastewater can help protect water quality.


By adopting the recommended strategies, tilapia producers can contribute to a more sustainable aquaculture industry. Consumers can also play a role by choosing responsibly sourced tilapia raised with practices that minimize environmental impact.

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The research highlights the importance of considering harvest weight and production practices when assessing the environmental footprint of aquaculture. It paves the way for more sustainable tilapia production, ensuring a healthy future for both our environment and our seafood supply.


The study was funded by the Fundação de Amparo à Pesquisa do Estado da Bahia – Brazil (FAPESB) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).

Lívia Paola Silva Petroski
Graduate Program in Animal Science (PPGZ), School of Veterinary Medicine and Animal Science, Federal University of Bahia (UFBA), Milton Santos Avenue, 500, Ondina, Salvador, BA 40170-110, Brazil
Email: lpspetroski@gmail.com

Luiz Vítor Oliveira Vidal
Graduate Program in Animal Science (PPGZ), School of Veterinary Medicine and Animal Science, Federal University of Bahia (UFBA), Milton Santos Avenue, 500, Ondina, Salvador, BA 40170-110, Brazil
Email: vidal@ufba.br

Petroski, L. P. S., Medeiros, D. L., & Vidal, L. V. O. (2024). The fish weight at slaughter influences energy and environmental performance of fish farming: The case of Nile tilapia production in cages. Aquaculture, 740757. https://doi.org/10.1016/j.aquaculture.2024.740757