State Key Laboratory of Marine Environmental Science & College of Ocean and Earth Sciences, Xiamen University, Xiamen 361005, China.
Marine and Environmental Biology, University of Southern California, Los Angeles, CA, United States.
Sci Total Environ. 2024 Oct 15;947:174345. doi: 10.1016/j.scitotenv.2024.174345. Epub 2024 Jul 1.
Seaweed cultivation can inhibit the occurrence of red tides. However, how seaweed aquaculture interactions with harmful algal blooms will be affected by the increasing occurrence and intensity of marine heatwaves (MHWs) is unknown. In this study, we run both monoculture and coculture systems to investigate the effects of a simulated heatwave on the competition of the economically important macroalga Gracilariopsis lemaneiformis against the harmful bloom diatom Skeletonema costatum. Coculture with G. lemaneiformis led to a growth decrease in S. costatum. Growth and photosynthetic activity (F/F) of G. lemaneiformis was greatly reduced by the heatwave treatment, and did not recover even after one week. Growth and photosynthetic activity of S. costatum was also reduced by the heatwave in coculture, but returned to normal during the recovery period. S. costatum also responded to the stressful environment by forming aggregates. Metabolomic analysis suggests that the negative effects on S. costatum were related to an allelochemical release from G. lemaneiformis. These findings show that MHWs may enhance the competitive advantages of S. costatum against G. lemaneiformis, leading to more severe harmful algal blooms in future extreme weather scenarios.
海藻养殖可以抑制赤潮的发生。然而，海藻养殖与有害藻华之间的相互作用将如何受到海洋热浪（MHWs）发生频率和强度增加的影响尚不清楚。在这项研究中，我们进行了单养和混养系统实验，以研究模拟热浪对经济上重要的大型海藻鹅掌菜（Gracilariopsis lemaneiformis）与有害藻华硅藻骨条藻（Skeletonema costatum）竞争的影响。与鹅掌菜混养会导致骨条藻的生长减少。热浪处理大大降低了鹅掌菜的生长和光合作用（F/F），即使在一周后也没有恢复。混养中骨条藻的生长和光合作用也受到热浪的影响，但在恢复期恢复正常。骨条藻也通过形成聚集体对胁迫环境做出反应。代谢组学分析表明，对骨条藻的负面影响与鹅掌菜释放的化感物质有关。这些发现表明，海洋热浪可能会增强骨条藻相对于鹅掌菜的竞争优势，导致未来极端天气情景下更严重的有害藻华。
