El Niño 2026 and Its Implications for Aquaculture: The Need for Climate Responsive Monitoring Systems

A recent study published in Nature Communications finds that Super El Niño occurrences can cause sudden and long-term shifts in the climate regime, impacting important factors like surface air temperature and sea surface temperature. Using observational datasets and climate model simulations, the study shows that these extreme El Niño events significantly increase the likelihood of long-lasting climatic transitions compared to regular ENSO events. The impacts vary dramatically by region. Across the Indian subcontinent, El Niño has historically weakened monsoon rainfall and increased temperatures by altering atmospheric circulation patterns that normally carry moisture from the Arabian Sea and Bay of Bengal. In contrast, southern regions of the Americas and southern United States experience increased rainfall, along with associated hazards like mudslides and flash flooding. 

These disturbances affect aquatic ecosystems that sustain fisheries and aquaculture production systems globally, going beyond atmospheric processes with many studies finding that the global fish production typically reducing during extreme El Niño (World Organisation for Animal Health, 2023) . Blue Foods such as  fish and crustacean biological processes are closely linked to environmental factors like temperature, dissolved oxygen, and nutrient dynamics; aquatic ecosystems are especially vulnerable to changes in the climate.. Changes in the distribution of species, variations in primary productivity, a rise in the frequency of marine heatwaves, and modifications to the hydrological cycles impacting aquatic ecosystems are common ways that these effects show up. 

Climate Sensitivity of Aquaculture Production Systems

Aquaculture has emerged as one of the world's fastest-growing food production sector, making a substantial contribution to rural lives, nutrition, and food security is still heavily reliant on environmental stability. Aquaculture has seen geographical shifts as a result of rising temperatures; species that were formerly restricted to particular thermal niches are now migrating to cooler waters. Since fish and shrimp are ectothermic organisms, meaning their physiological functions, such as growth, feeding behavior, and metabolism, are strongly regulated by external environmental conditions, particularly water temperature and water chemistry.

1. Metabolic Responses

For every 10°C increase in water temperature, ectotherms increase their metabolic rate by two to three times. However, when temperatures exceed thermal threshold level, species' metabolic rate decreases due to physiological stress. Hyper-thermal stress induces the reallocation of metabolic energy needed to sustain growth and reproduction to the restoration of physiological equilibrium. The aquatic species cease feeding during this phase until the temperature returns to their optimum thermal range.

2. Oxygen Availability

Aquatic species' immunity, metabolic rate, and oxygen requirement are all directly impacted by temperature. Rising water temperatures alter the solubility and availability of oxygen which limits the synthesis of ATP to support metabolic alterations and hinders aerobic metabolism, ultimately resulting in physiological stress and reduced growth (Mugwanya et al., 2022). 

3. Osmoregulation and Ionic Balance

Fish maintain a dynamic equilibrium of water and ions between the external environment and their internal body fluids, called “osmotic regulation”. The control of this ionic balance is regulated by gills, kidneys, and intestine. Fish osmoregulation is hindered by high temperatures, which results in osmotic stress, failed ion regulation, and increased mortality. Heat stress reduces gill Na+-K+-ATPase activity and increases gill tissue permeability, ultimately causing electrolyte imbalances and reduced metabolic efficiency. In contrast to marine species, freshwater species experience a net loss of ions when water temperature increases. In order to compensate for ion loss and ion gain in freshwater and marine species, respectively, fish increases the activities of Na+–K+-ATPase and Na+–K + -Cl- cotransporter (NKCC) in the gills, intestine, and kidney. Additionally, freshwater species' epithelial permeability reduces to slow down ion loss, while marine species' permeability rises to accelerate ion efflux. When a species is subjected to both osmotic and hyperthermal stress, it usually suffers heavily and eventually may die (Vargas-Chacoff et al., 2018).

4. Temperature-driven Disease Dynamics

Temperature fluctuations also influence fish immunity, reproductive cycles, and disease susceptibility. Growth rate, sexual maturity, and spawning cycles are also greatly influenced by temperature fluctuations. Higher temperatures favor the growth and spread of disease-causing pathogens, which are an emerging threat to global aquaculture production. Moreover, rising water temperatures enhance the severity of infectious diseases, which could result in large economic losses if improperly treated. For instance, disease outbreaks in tilapia caused by Streptococcus agalactiae typically happen at temperatures higher than 26°C. Fish vaccination efficacy is also impacted by high temperatures. When Nile tilapia were vaccinated against S. agalactiae and raised at high temperatures (29 and 33°C), the vaccine's effectiveness was halted, and the fish's immunity was suppressed (Wang et al., 2020). Similarly, studies have shown that a 1°C increase in water temperature can raise mortality rates due to viral infections by 1.47-8.33% in oysters and 2.18-5.37% in fish (Combe et al., 2023).

5. Algal Bloom and Water Quality Instability

In open-loop aquaculture systems, rising temperatures often stimulate phytoplankton proliferation, which may lead to dense algal blooms. Although moderate phytoplankton growth enhances the productivity of the system, excessive blooms can destablize water quality by causing diurnal fluctuations in dissolved oxygen and pH levels. For instance, a harmful algal bloom of Pseudochattonella cf. verruculosa coinciding with a strong El Niño event killed nearly 12% of Chilean salmon production in early 2016, the worst mass mortality of fish and shellfish ever recorded in coastal western Patagonia, generating huge economic losses over US $800 million (León-Muñoz et al., 2018).

6. Economic Implications

El Niño represents a systemic risk to global food security. Normally, aquaculture production changes by less than 1% compared to long-term averages. However, during extreme El Niño events, production drops by about 2.1% overall and around 3% for marine and brackish water aquaculture (FAO, 2020). For every degree Celsius increase in water temperature, operational costs may increase by 10-15% due to the necessity for extra cooling systems and treatments for heat-related diseases and stress (Ma et al., 2021).

The Need for Climate-Responsive Aquaculture Management

Current evidence suggests that a comprehensive understanding of the long-term effects of climatic events is still not fully understood. While the scientific knowledge of climate systems like El Niño is quite advanced, there is still limited practical knowledge on how these events directly impact aquaculture systems and the communities who depend on them. In aquaculture, climate change and ENSO-driven variability primarily manifest through fluctuations in key water quality parameters, including temperature, salinity, dissolved oxygen, and ammonia. These factors directly influence immune responses and metabolic rates,ven short-term deviations can induce physiological stress, Beyond these direct impacts, climate variability alters the ecological balance within culture systems. Changes in primary productivity, microbial dynamics, and water chemistry can destabilize culture ecosystems, often triggering disease outbreaks and mass mortality events. Such impacts may lead to lasting shifts in sustained declines in aquaculture productivity. Addressing these pain points requires a transition from reactive to proactive management, driving the necessity for predictive models capable of assessing climate-driven changes over multi-decadal time scales.

Adaptation and coping strategies in aquaculture can be differentiated across multiple dimensions: spatial scale (international, national, and local), temporal scale (short-, medium-, and long-term), sector (small-scale, medium-scale and large-scale), actors (fishers, fish farmers, fish workers, companies, and management authorities), and type of impact (such as changes in production, disease outbreaks, and environmental stressors). Climate-resilient aquaculture requires the integration of environmental monitoring, geospatial data, and field-level information. Such systems enable aqua-producers to anticipate early signs of environmental stress and implement preventive or corrective measures before conditions translate into major production risks. 

Bridging the Gap between Climate Science and Aquaculture Decision Making 

The escalating severity of ENSO events, combined with the systemic vulnerabilities of aquaculture production systems, demands a fundamentally different approach. Traditional management approaches primarily based on observational experience are no longer sufficient to address the rapid environmental shifts associated with climate variability.

The AI-native aquaculture intelligence platform Twingills, developed by NatureDots, represents this next generation of climate-responsive aquaculture production management. Functioning as an advanced environmental intelligence system powered by 6 billion data points and over 30 AI- and science-backed models, it integrates real-time water quality monitoring with climate-risk forecasting to help aquaculture systems anticipate environmental shocks rather than merely react to them. Its foundational architecture is the digital twin, a continuously updated virtual replica of the physical farm environment, that integratesthe TwinOrbix AI-sensors on water health with other multi-data sources such as satellite data, sensors, into a single unified decision-support system.

At the macro-environmental level, Twingills provide a broader environmental and climatic perspective that includes regional climate indicators such as precipitation, air temperature, humidity and other key atmospheric variables, to track  early insights into ecosystem dynamics that influence aquaculture systems, and deduce factors such as heat stress, and hydrological variability.

At the farm level or production unit level, the platform integrates site-specific information in real time, to spot deviations from optimal environmental ranges before they translate into physiological stress for cultured species. 

Through the integration of macro-environmental climate signals and farm-level environmental monitoring, the Twingills platform  forecasts climate and water risk 7-90 days in advance to provide specific recommendations like adjustments in feeding, aeration management, water exchanges, or preemptive disease measures, while optimizing operational efficiency by up to 30%.

In the context of increasing climate variability and the high-confidence forecasts of El Niño conditions this year, the ability to anticipate environmental stress events will become increasingly critical for safeguarding aquaculture productivity and the livelihoods of the millions who depend on it.

References

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