8. Enhancing Stress Resilience in Marine Environments Through Probiotics and Prebiotics

Various marine animal health issues have been linked to environmental stress. One of the most well‐understood effects of climate change on aquatic diseases is the impact of rising temperatures. Higher temperatures can negatively affect parasites and pathogens, especially if they are exposed to temperatures outside their normal range. This can lead to increased growth of harmful bacteria and heightened pathogenicity, driven by changes in the expression of virulence factors. Temperature changes can also disrupt the microbiomes of marine hosts, potentially leading to immune suppression and increased susceptibility to diseases. Warmer winter sea surface temperatures may allow pathogens to thrive year‐round, potentially causing new diseases or expanding the range of infectious agents. Research has shown that probiotic bacteria could play a crucial role in enhancing the immune system of marine aquatic animals and preventing harmful bacteria from infiltrating the GIT [178]. Probiotic supplementation has been shown to strengthen the immune system and mitigate the negative effects of stress, thereby reducing the likelihood of adverse outcomes (Table 4) [179]. This can be achieved by maintaining a stable digestive system and promoting a healthy gut microbiota through probiotic intervention in water. Numerous studies have highlighted the potential importance of probiotics in the marine environment, particularly in challenging environmental conditions. Probiotics offer a promising solution to combat the detrimental effects of environmental stress on marine animals and enhance their overall health and resilience. Figure 8 illustrates how probiotics and prebiotics can be implemented in marine environments to alleviate the harmful consequences of environmental stress. Table 5 presents research on probiotic supplementation in marine environments to reduce stress levels. Figure 8, on the other hand, illustrates the implementation of probiotics and prebiotics in marine environments to alleviate the harmful consequences of environmental strain (the pressure human activities exert on natural systems, pushing them beyond their regenerative capacity and jeopardizing the ecological balance).

Figure 8: Implementation of probiotics and prebiotics in marine environments to alleviate the harmful consequences of environmental strain.

Species name | Probiotics | Stress type | Mitigation | References
Coral Pocillopora damicornis | Beneficial microorganisms for corals (BMCs or coral probiotics) | Thermal stress (30°C) | The effects of the pathogen Vibrio coralliilyticus can even improve calcification at high temperatures at the skeletal levels | [180]
Pocillopora damicornis | Putatively beneficial microorganisms for corals (pBMCs) | Thermal stress (26 and 30°C) | Vibrio coralliilyticus | [179]
Litopenaeus vannamei | Bacillus subtilis |  | Opportunistic pathogens (two strains of Vibrio cholerae, V. owensii, two strains of V. rotiferianus, V. fluvialis, Photobacterium damselae subsp. damselae, one strain of V. campbellii, V. vulnificus, and V. parahaemolyticus) | [181]
Olive flounders (Paralichthys olivaceus) | Lactococcus lactis WFLU12 |  | Alleviate stress levels in fish | [182]
Hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) | Bacillus subtilis strains |  | Vibrio harveyi stress resilience | [183]
Litopenaeus vannamei | Bacillus sp. and Lactobacillus sp |  | Vibrio harveyi bacterial stress resistance | [184]