Seaweeds account for nearly 30% of global aquaculture production by volume, and their cultivation provides important opportunities for employment and wealth generation, particularly in rural coastal communities. Eucheumatoids (Kappaphycus and Eucheuma spp.) are tropical red algae commercially cultivated as raw material for production of carrageenans, particularly in South-East Asia and the Western Indian Ocean region. Diseases and pests are major limiting factors in eucheumatoid production, particularly a condition known as ‘ice-ice’ disease (IID). IID is characterized by bleaching of the thallus followed by the disintegration of affected tissues, leading to a loss of biomass and reduced carrageenan yield. IID has been associated with unfavourable changes in environmental conditions, particularly an increase in sea water temperature and a decrease in salinity, and infection by opportunistic or pathogenic bacteria. However, given that no single or combined causal agents have been definitely identified, IID may be considered a complex pathobiotic syndrome in which multiple factors contribute to the development of disease signs. Here, we review current knowledge of the abiotic and biotic factors associated with the development of IID, and the strategies employed to mitigate economic losses resulting from disease outbreaks. We discuss syndromic diseases in other marine holobionts, particularly other red algae and corals, in relation to their similarity to IID, and suggest the application of comprehensive and complementary methodologies, including high-throughput sequencing and high-quality microscopy, for enhancing our understanding of the pathological and microbiological processes associated with IID signs.

中文翻译：

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冰-冰病：热带海藻养殖中的环境和微生物驱动综合征

海藻占全球水产养殖产量的近 30%，其种植为就业和财富创造提供了重要机会，特别是在农村沿海社区。Eucheumatoids ( Kappaphycus和Eucheuma )spp.) 是热带红藻，作为生产卡拉胶的原料，特别是在东南亚和西印度洋地区，被商业化种植。疾病和害虫是​​类油菜生产的主要限制因素，特别是被称为“冰-冰”病 (IID) 的疾病。IID 的特征是菌体漂白，随后受影响的组织解体，导致生物量损失和角叉菜胶产量降低。IID 与环境条件的不利变化有关，特别是海水温度升高和盐度降低，以及机会性或病原菌感染。然而，鉴于尚未明确确定单一或组合的致病因素，IID 可能被认为是一种复杂的病原综合征，其中多种因素导致疾病体征的发展。在这里，我们回顾了与 IID 发展相关的非生物和生物因素的当前知识，以及用于减轻疾病爆发造成的经济损失的策略。我们讨论了其他海洋 holobionts，特别是其他红藻和珊瑚中与 IID 的相似性的综合征疾病，并建议应用全面和互补的方法，包括高通量测序和高质量显微镜，以增强我们对与 IID 体征相关的病理和微生物过程。以及为减轻疾病爆发造成的经济损失而采取的策略。我们讨论了其他海洋 holobionts，特别是其他红藻和珊瑚中与 IID 的相似性的综合征疾病，并建议应用全面和互补的方法，包括高通量测序和高质量显微镜，以增强我们对与 IID 体征相关的病理和微生物过程。以及为减轻疾病爆发造成的经济损失而采取的策略。我们讨论了其他海洋 holobionts，特别是其他红藻和珊瑚中与 IID 的相似性的综合征疾病，并建议应用全面和互补的方法，包括高通量测序和高质量显微镜，以增强我们对与 IID 体征相关的病理和微生物过程。