medicinal plants in aquaculture health management: a systematic review of their efficacy for disease prevention and control

The exponential growth of global aquaculture, crucial for sustaining the world s seafood supply, is perpetually threatened by infectious disease outbreaks that cause staggering economic losses. the conventional dependence on chemotherapeutants, including antibiotics and synthetic chemicals, has led to severe repercussions such as the proliferation of antimicrobial resistance (amr), residual accumulation in tissues, and environmental degradation, compelling the industry to seek sustainable, eco-friendly alternatives. medicinal plants, repositories of diverse bioactive compounds like alkaloids, flavonoids, tannins, and essential oils, present a highly promising solution due to their broad-spectrum antimicrobial, immunostimulant, growth-promoting, and antioxidant properties. this systematic review synthesizes a global body of evidence, with significant contributions from both international and iranian research, to critically evaluate the effects of various medicinal plants on the health, disease resistance, and productivity of farmed aquatic species. the consolidated findings robustly demonstrate that dietary supplementation or immersion baths with extracts from plants such as garlic (allium sativum), nettle (urtica dioica), thyme (thymus vulgaris), and asian medicinal herbs can significantly enhance innate and adaptive immune parameters, improve growth performance and feed utilization, and confer substantial protection against bacterial, viral, fungal, and parasitic pathogens. the mechanisms are multifaceted, encompassing direct pathogen inhibition, modulation of cellular and humoral immune responses, enhancement of antioxidant capacity, and improvement of gut health. this review concludes that phytogenic compounds are viable, natural, and effective alternatives to synthetic chemicals in integrated aquaculture health management. however, challenges regarding standardization, optimal dosage, delivery methods, and large-scale application must be addressed through future research to fully integrate these natural products into sustainable aquaculture practices.