Laminaria digitata Supplementation as a Climate-Smart Strategy to Counteract the Interactive Effects of Marine Heatwaves and Disease Outbreaks in Farmed Gilthead Seabream (Sparus aurata)
2025
Isa Marmelo | Tomás Chainho | Daniel Bolotas | Alícia Pereira | Busenur Özkan | Cátia Marques | Iris A. L. Silva | Florbela Soares | Pedro Pousão-Ferreira | Elsa F. Vieira | Cristina Delerue-Matos | Zélia Silva | Paula A. Videira | Tiago Repolho | Mário Sousa Diniz | António Marques | Ana Luísa Maulvault
Extreme weather events, such as marine heatwaves (MHWs), pose serious threats to the aquaculture sector, facilitating the occurrence of disease outbreaks and compromising farmed animals&rsquo: welfare and survival. Hence, finding eco-innovative strategies to improve animal immunocompetence is essential to assure aquaculture&rsquo:s sustainability and resilience in a rapidly changing ocean. This study evaluated the immunostimulatory potential of Laminaria digitata powder (0.3% and 1.5%) and extract (0.3%) in juvenile gilthead seabream (Sparus aurata) exposed to a Vibrio harveyi outbreak during a Category III MHW event (T = 25.7 °:C). Overall, L. digitata supplementation did not significantly affect fish immunocompetence under optimal rearing conditions (T = 21.4 °:C: no infection), nor did it induce any adverse effects. However, both the powder (1.5%) and extract (0.3%) forms of L. digitata supplementation effectively mitigated the negative impacts prompted by the MHW and Vibrio harveyi infection&mdash:evidenced by improvements in fish health indicators, hematological parameters, leukocyte viability, granulocyte proportions, and reductions in peroxidase activity and immunoglobulin M levels. From an economic standpoint, supplementation with 1.5% L. digitata powder emerged as the most promising strategy, offering a practical balance between effectiveness and affordability for large-scale applications. These findings highlight the potential of L. digitata as an immunostimulatory aquafeed supplement, with promising benefits for fish health and resilience under adverse rearing conditions.
显示更多 [+] 显示较少 [-]