Shrimp Welfare and Sustainability

Many thanks to the Aquatic Animal Alliance and Fish Welfare Initiative for the ideas that inspired this post.

Can improving shrimp welfare lead to greater sustainability?

When animal welfare isn’t taken into consideration in shrimp production systems, the results include poor health, more disease, need for antibiotic use, higher mortality,
environmental and ecosystem impacts, and ultimately lower resource efficiency and productivity. Looking after the welfare of shrimps can mitigate many of the most pressing issues created by the industry as it stands today.

Water Pollution

Oxygen and ammonia levels, temperature, salinity and pH are key to the welfare of all aquatic animals, including shrimps [1]. Poor water quality can lead not only to compromised immune systems in shrimps [1] (and in extreme cases, to death by suffocation or poisoning [2]), but also to the contamination of nearby bodies of water, as well as salinization and acidification of the soil [3]. Water pollution can cause large spillover events if best management practices are not followed. For example, algal blooms can deplete oxygen levels in the water [4] and produce harmful toxins that may kill animals and cause human illness [5].

Disease Prevention

Diseases that exist within the normal microflora of shrimps can thrive under high stocking densities (with density depending on the intensity of the production method [6]), enabling pathogenic outbreaks [7]. 

Poor shrimp health can often lead to inefficient production. For example, diseased shrimps have higher mortality rates and reduced yields [8]. Keeping suffering and stress to a minimum protects animal welfare while also ensuring high quality shrimps [9]. Since farmed shrimps are ultimately raised for human consumption, diseases in shrimps directly (and negatively) affect food safety. Benchmark, an aquaculture research institute, has identified disease as one of the top sustainability challenges facing the shrimp industry today [10]. 

In order to combat bacterial diseases suffered by shrimps, antibiotics are used extensively in shrimp farming [11]. The indiscriminate use of antibiotics to stop diseases promotes the emergence of antibiotic-resistant bacteria [12]. This has the potential to hinder the overall effectiveness of antibiotics in the future, which could affect not only shrimps but also humans and other animals. One of the best ways to minimize the need for antibiotics is to rear shrimps under greater welfare conditions, promoting better immune systems, thereby lowering the susceptibility of disease outbreaks [13]. 

Ecosystems

Many consumers shift their consumption from wild-caught aquatic animals to those raised in aquaculture, under the assumption that such a shift will eliminate the impact that their diet has on aquatic biodiversity. Unfortunately, this is not the case. Feed for carnivore and omnivore aquatic animals such as shrimps still requires a significant amount of wild fish in its composition [14]. 

Another way in which shrimp farming can hurt the environment is by spreading diseases in their surrounding areas. The densely stocked ponds, teeming with immunocompromised shrimps are the ideal breeding grounds for pathogens and parasites to flourish. This, combined with poor biosecurity measures, can wreak havoc on the local wildlife as wastewater is discharged back into the rivers. On the contrary, in small quantities (for example from less intensive operations), water effluent from shrimp farms can be beneficial due to its nutrient content and organic load [15].

​Many shrimps are wild-caught using bottom trawlers [16]. This process includes trawling for animals to feed shrimp with fish meal. Bottom trawling releases a gigaton of carbon dioxide from the seafloor each year (almost as much as the emissions of the whole African continent in 2010) [17], leads to a significant amount of bycatch [18], and results in ghost fishing [19].

​Shrimp farms are frequently built on the site of mangrove forests which are cut down to make way for ponds, which causes significant carbon losses. The carbon intensity of shrimp farming from deforested mangroves is 10 times greater than that of beef grown in deforested Amazonian rainforest [20].

Livelihoods

Local communities often rely on fisheries for employment, food and health. However, poor management and unsustainable fishing can result in overfishing and excessive bycatch [18]. This threatens the future viability of family businesses and employment opportunities, while worsening food insecurity and public health issues.

​Local and indigenous communities rely on mangrove forests for food, income and other resources. Shrimp farms can privatise and destroy this resource and when communities fight back, repercussions can be tragic, including loss of livelihoods, rapes and murders [21]. Shrimp processing facilities [22] and fishing for shrimp feed [23] are practices that have both included human trafficking and slave-like working conditions.

​Finally, people increasingly care about animal welfare and where their food comes from [24]. Raising higher welfare shrimps enables producers to remain viable in a changing marketplace and more sustainable seafood can sell for a price premium, increasing revenue [25].

References

  1. Wiyoto et al., 2016 - Water Quality and Sediment Profile in Shrimp Culture with Different Sediment Redox Potential and Stocking Densities Under Laboratory Condition

  2. Allan et al., 1991 - Lethal levels of low dissolved oxygen and effects of short-term oxygen stress on subsequent growth of juvenile Penaeus monodon

  3. Thi Anh et al., 2010 - Water pollution by intensive brackish shrimp farming in south-east Vietnam: Causes and options for control

  4. National Ocean Service: National Oceanic and Atmospheric Administration - What is a dead zone?

  5. National Ocean Service: National Oceanic and Atmospheric Administration - What is a harmful algal bloom?

  6. Shrimp Welfare Project - The Shrimp Supply Chain

  7. Le Moullac et al., 2000 - Environmental factors affecting immune responses in Crustacea

  8. Wang et al., 2021 - A convenient polyculture system that controls a shrimp viral disease with a high transmission rate

  9. Yu et al., 2020 - Growth and health responses to a long-term pH stress in Pacific white shrimp Litopenaeus vannamei

  10. Benchmark Insights - Technologies shaping the future of shrimp production

  11. Holmström et al., 2003 - Antibiotic use in shrimp farming and implications for environmental impacts and human health

  12. Global Seafood Alliance, 2019 - Why are antibiotic residues in farmed shrimp a big deal?

  13. Millard et al., 2021 - How do abiotic environmental conditions influence shrimp susceptibility to disease? A critical analysis focussed on White Spot Disease

  14. Aquatic Life Institute, 2021 - Interpreting “Blue Loss” and Measuring the Hidden Animals in Our Food System

  15. The Fish Site, 2021 - How to manage water effluent from shrimp farms

  16. Transform Bottom Trawling - Trawling Impacts

  17. Smithsonian Magazine, 2021 - Seafloor Trawl Fishing May Release as Much Carbon as Air Travel

  18. Davies et al., 2009 - Defining and estimating global marine fisheries bycatch

  19. Marine Conservation Institute - Help Us End Destructive Fishing

  20. Science.org, 2012 - The Carbon Footprint of a Shrimp Cocktail

  21. Forest People Programme, 2010 - Global Shrimp Network meeting in Khulna, Bangladesh, February 2010

  22. Associated Press, 2015 - Enslaved in Shrimp Sheds

  23. The Guardian, 2014 - Revealed: Asian slave labour producing prawns for supermarkets in US, UK

  24. Buller et al., 2018 - Towards Farm Animal Welfare and Sustainability

  25. Asche et al. 2021 - The value of responsibly farmed fish: A hedonic price study of ASC-certified whitefish