有害的鞭毛藻及其产生的花朵对海洋生物和人类健康构成威胁。然而,到目前为止,全球海洋生物地图经常忽略有害微生物。随着有害藻华(HAB)频率的增加,严重程度,和程度,了解有害鞭毛虫及其驱动因素的分布对其管理至关重要。我们用了MaxEnt,随机森林,和集合模型来绘制亚历山大属中代表性HABs物种的栖息地,包括A.catenella,A.minutum,和A.pacificum。由于先前研究中使用的物种发生记录仅基于形态,可能导致错误识别,我们用分子标准校正了这些物种的分布记录。结果表明,关键的环境驱动因素包括到海岸线的距离,测深,海面温度(SST),和溶解氧。Alexandriumcatenella在温带至寒冷地区蓬勃发展,是由低SST和高氧水平驱动的。Alexandriumpacificum主要居住在温带的北太平洋,更喜欢温暖的SST和较低的氧气水平。Alexandriumminutum普遍蓬勃发展,并广泛适应SST和氧气。通过分析记录有HAB事件的地点的生境适宜性,我们发现,高栖息地适宜性可以作为开花风险的参考指标。因此,我们提出了一种定性方法,根据生境适宜性在空间上评估有害藻类风险。在全球风险地图上,沿海温带海域,比如地中海,西北太平洋,澳大利亚南部,面临更高的风险。尽管HAB目前地理分布有限,我们的研究发现,这些有害藻类具有很高的环境耐受性,可以在不同的栖息地中茁壮成长。如果气候变化或海洋条件变得更加有利,HAB的影响可能会增加。海上运输也可能将有害藻类传播到新的未受影响的生态系统。这项研究开创了基于栖息地适宜性的有害藻类风险评估。
Harmful dinoflagellates and their resulting blooms pose a threat to marine life and human health. However, to date, global maps of marine life often overlook harmful microorganisms. As harmful algal blooms (HABs) increase in frequency, severity, and extent, understanding the distribution of harmful dinoflagellates and their drivers is crucial for their management. We used MaxEnt, random forest, and ensemble models to map the habitats of the representative HABs species in the genus
Alexandrium, including A. catenella, A. minutum, and A. pacificum. Since species occurrence records used in previous studies were solely morphology-based, potentially leading to misidentifications, we corrected these species\' distribution records using molecular criteria. The results showed that the key environmental drivers included the distance to the coastline, bathymetry, sea surface temperature (SST), and dissolved oxygen.
Alexandrium catenella thrives in temperate to cold zones and is driven by low SST and high oxygen levels.
Alexandrium pacificum mainly inhabits the Temperate Northern Pacific and prefers warmer SST and lower oxygen levels.
Alexandrium minutum thrives universally and adapts widely to SST and oxygen. By analyzing the habitat suitability of locations with recorded HAB occurrences, we found that high habitat suitability could serve as a reference indicator for bloom risk. Therefore, we have proposed a qualitative method to spatially assess the harmful algae risk according to the habitat suitability. On the global risk map, coastal temperate seas, such as the Mediterranean, Northwest Pacific, and Southern Australia, faced higher risks. Although HABs currently have restricted geographic distributions, our study found these harmful algae possess high environmental tolerance and can thrive across diverse habitats. HAB impacts could increase if climate changes or ocean conditions became more favorable. Marine transportation may also spread the harmful algae to new unaffected ecosystems. This study has pioneered the assessment of harmful algal risk based on habitat suitability.