fa عمومى General پژوهشي Research <span style="font-size:11pt"><span style="line-height:82%"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:82%"><span new="" roman="" style="font-family:" times="">Intensification in aquaculture has increased challenges related to infectious diseases, prompting the search for alternatives to traditional antibiotic treatments, which often result in chemical residues, environmental pollution, and antimicrobial resistance. This review evaluates marine macroalgae and terrestrial plant extracts as sustainable antimicrobial agents, focusing on their extraction methods, phytochemical composition, and efficacy. Marine algae, particularly brown and red species, contain unique bioactive compounds such as sulfated polysaccharides, phenolics, and pigments. These extracts demonstrate potential as growth promoters and immunostimulants; however, safety is paramount, as studies on zebrafish have revealed teratogenic effects at high concentrations. Research confirms enhanced growth performance in tilapia and shrimp fed diets supplemented with algal extracts, including improved feed conversion ratios and specific growth rates. The immunomodulatory properties of these extracts activate defense mechanisms, such as increased lysozyme activity and elevated hemocyte counts. Additionally, macroalgal extracts help preserve post-harvest seafood quality by inhibiting spoilage and oxidation. Key challenges for commercial application include standardizing extraction procedures, establishing safety thresholds, and determining optimal dosing levels. Overall, plant and seaweed extracts present a promising alternative to antibiotics by enhancing growth, immunity, and disease resistance in aquaculture species. Their efficacy depends on extraction techniques, bioactive compound profiles, and precise dosing to avoid toxicity. Further research is necessary to standardize protocols and evaluate long-term effects, representing a sustainable strategy to improve aquaculture productivity while mitigating the risks of antimicrobial resistance.</span></span></span></span></span></span> &nbsp; Phytogenic feed additives, Marine macroalgae, Immunostimulation, Antimicrobial resistance, Sustainable aquaculture 89 98 http://injbir.com/browse.php?a_code=A-10-1-41&slc_lang=fa&sid=1 S. Pourmozaffar 1003194753284600617 1003194753284600617 Yes Persian Gulf Mollusks Research Station, Persian Gulf and Oman Sea Ecology Research Center, Iranian Fisheries Sciences Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Bandar Lengeh, Iran S. Tamadoni Jahromi 1003194753284600618 1003194753284600618 No Persian Gulf and Oman Sea Ecology Research Center, Iranian Fisheries Sciences Research Institute (IFSRI), Agricultural Research Education and Extension Organization (AREEO), Bandar Abbas, Iran R. Nahavandi 1003194753284600619 1003194753284600619 No Animal Science Research Institute of Iran (ASRI), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran M.K. Pazir 1003194753284600620 1003194753284600620 No Iranian Shrimp Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education & Extension Organization (AREEO), Bushehr, Iran Z. Amini Khoei 1003194753284600621 1003194753284600621 No Off-shore Fisheries Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Chabahar, Iran S.B. Setufe 1003194753284600622 1003194753284600622 No Department of Fisheries and Water Resources, University of Energy and Natural Resources, Sunyani, Ghana