Evolving Challenges: Recent Mortality Events in Aquaculture
From Newfoundland to Ecuador to Scotland, recent mortality events show how environmental shifts, disease pressures, and operational challenges can combine in complex ways. This is not new, nor are these events isolated. They highlight the biological vulnerabilities inherent in aquaculture systems and emphasize the importance of solutions that integrate climate adaptation, operational efficiency, and animal health.
When Aquaculture Losses Share a Common Thread
Environmental stress, husbandry practices, and disease often combine in cascading ways that weaken animals and destabilize production. Recent incidents around the world illustrate how climate variability or seasonal changes can push systems beyond their limits, especially when management or disease control is already under pressure.
In Newfoundland, Mowi reported nearly 475,000 salmon deaths, about 30 percent mortality at two sites. The company attributed the losses to unusually warm water and low dissolved oxygen. These stressors disrupt fish physiology, weaken their immune systems, and increase their susceptibility to parasites, such as sea lice. Decades of studies have shown that fluctuations in temperature or oxygen can trigger metabolic stress and systemic inflammation, which reduce survival (Barton, 2002; Iversen et al., 2021).
Similar patterns are being observed elsewhere. In Ecuador, The Fish Site reported that cooler waters during La Niña periods slow shrimp growth, delay harvests, and raise the incidence of White Spot Syndrome Virus (WSSV) and Early Mortality Syndrome (EMS) in shrimp farms. (thefishsite.com) Rainfall and salinity fluctuations further stress the animals, creating conditions that favor pathogens. In Scotland, Fish Farming Expert warned that warming waters will likely intensify gill diseases and sea lice pressure in salmon, with more frequent marine heatwaves linked to mortality events. (fishfarmingexpert.com) Even bacterial pathogens are responding to environmental change. The Global Seafood Alliance Advocate highlighted how warming temperatures can increase the virulence of Aeromonas hydrophila, a major pathogen in finfish aquaculture, making outbreaks more severe even under good management conditions. (globalseafood.org)
Meanwhile, Bakkafrost's freshwater operations in Scotland experienced a disease outbreak, resulting in a £26 million loss and prompting a restructuring of its management approach. The episode illustrated that even controlled environments such as hatcheries face systemic risks. In this case, the challenge appeared to stem from the complex interplay between disease pressure and operational stress, underscoring the multifaceted nature of resilience-building, even in enclosed systems.
Taken together, these cases demonstrate that whether the trigger is climate, disease, or management, the underlying vulnerability remains the same: biological fragility that leaves farms vulnerable to compounding stressors.
Resilience Requires More Than One Fix—Nutrition Included
These mortality events underscore that aquaculture resilience can't hinge on any single solution. Success requires a systems approach, one that recognizes the interplay between environment, management, genetics, disease control, and nutrition.
Nutrition, in particular, is a powerful but often underleveraged tool. Research indicates that feed additives enriched with bioactive compounds, such as antioxidants, immunostimulants, and prebiotics, can enhance gut barrier function and modulate inflammatory responses, thereby improving animals' ability to withstand stress (Gomez et al., 2015; Dawood et al., 2019). Paired with proactive health protocols, selective breeding for stress resilience, and real-time environmental monitoring, nutritional strategies can significantly reduce mortality risk and improve overall farm performance.
The Path Forward
Aquaculture challenges are not accelerating; they are evolving, and so are the tools available to meet them. Keeping pace with new science, shifting conditions, and emerging solutions is no small task, especially when day-to-day operations demand constant attention. However, advances in nutrition, genetics, biosecurity, and environmental monitoring are providing producers with more options than ever to build resilience into their systems. Each farm's context is different, but the opportunity is the same: to combine these tools in ways that fit their operations, strengthen their stock, and stabilize their outcomes. The future of aquaculture isn't about doing more; it's about continually adapting with the best science and strategies available.
Knip can help with advanced nutrition solutions that support resilience and consistent production in an evolving ecosystem. Reach out to learn more at info@knipbio.com
References
Barton, B. A. (2002). Stress in fishes: a diversity of responses with particular reference to changes in circulating corticosteroids. Integrative and Comparative Biology, 42(3), 517–525.
Iversen, M. H., Finstad, B., and Nilssen, K. J. (2021). The physiology of salmonids exposed to stressors in intensive aquaculture. Reviews in Fish Biology and Fisheries, 31, 935–957.
Gomez, D., Sunyer, J. O., and Salinas, I. (2015). The mucosal immune system of fish: the evolution of tolerating commensals while fighting pathogens. Fish and Shellfish Immunology, 35(6), 1729–1739.
Dawood, M. A. O., Koshio, S., and Esteban, M. Á. (2019). Beneficial roles of feed additives as immunostimulants in aquaculture: a review. Reviews in Aquaculture, 11(4), 1–24.
Trade and Industry Reading
The impact of climate variability on Ecuador’s shrimp farms, The Fish Site (link)
Warming climate will not stop Scottish salmon farming, say scientists, Fish Farming Expert (link)
Aquaculture and Aeromonas hydrophila: A complex interplay of environmental factors and virulence, Responsible Seafood Advocate (link)