Fumo James T, Nichols Patrick K, Ely Taylor, Marko Peter B, Moran Amy L, Powell Brian S, Williams Taylor M, Kosaki Randall K, Smith Celia M, Lopes Keolohilani H, Smith Jennifer E, Spalding Heather L, Krueger-Hadfield Stacy A, McDermid Karla J, Hauk Brian B, Morioka James, O'Brien Kevin, Kennedy Barbara, Leliaert Frederik, Fujii Mutue T, Nelson Wendy A, Draisma Stefano G A, Sherwood Alison R
School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States.
Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States.
PeerJ. 2025 Jun 23;13:e19610. doi: 10.7717/peerj.19610. eCollection 2025.
The cryptogenic marine red alga was first observed in 2016 in subtidal habitats at Manawai (Pearl and Hermes Atoll) in the Papahānaumokuākea Marine National Monument (PMNM), Hawai'i. Without molecular or morphological matches to any known species, it was described in 2020 and declared cryptogenic. This alga has substantially increased in benthic cover and has been discovered on two additional atolls in PMNM: Kuaihelani (Midway) and Hōlanikū (Kure). It exhibits several characteristics indicative of non-native origins including putative prior absence in the region, persistence in high densities over nearly a decade, apparent lack of native herbivore pressure, and strong tetrasporophytic bias. Importantly, it is negatively impacting the culturally and ecologically valuable reefs of PMNM. The geographical origin of this putative invasion is unknown, and there are no published reports of the species occurring anywhere other than PMNM. The central Pacific location of Hawai'i allows a broad range of potential sources for the origin of . Taxonomic ambiguities within the genus and challenges associated with sampling necessitate the development of a narrowed set of search locations and efficient search strategies to detect the species outside of PMNM. Attachment to floating debris is a potential introduction vector for into PMNM, and an oceanographic model was used to identify the most likely source locations for this pathway between 2000 and 2015, including Japan in the western Pacific, Johnston Atoll, the Line Islands including Palmyra Atoll in the central Pacific, and Clipperton Atoll and the Galápagos Islands in the eastern Pacific. We used a recently developed and validated eDNA assay for detecting from three of the regions of interest to screen for with no samples yielding positive detections. We provide a framework for investigating positive eDNA field detections using in-water surveys, microscopy, and DNA barcoding. A parallel sampling effort targeting preserved specimens stored in global herbaria is also presented, which did not yield any detections. Several species remain targets for sequencing from global herbaria. Identification of the native range of is a critical step that will allow for an evaluation of its evolutionary ecology and any shifts that may have occurred that facilitated its putative invasion and subsequent spread, offering insights crucial for the development of mitigation strategies to safeguard PMNM against further risk.
这种隐源性海洋红藻于2016年首次在夏威夷帕帕哈瑙莫夸基亚海洋国家纪念区（PMNM）马纳瓦伊（珍珠和爱马仕环礁）的潮下带栖息地被发现。由于在分子或形态上与任何已知物种都不匹配，它于2020年被描述并被宣布为隐源性物种。这种藻类在底栖生物覆盖度上大幅增加，并在PMNM的另外两个环礁上被发现：库埃赫拉尼（中途岛）和霍拉尼库（库雷）。它表现出几个表明非本土起源的特征，包括该区域此前可能不存在、近十年来高密度持续存在、明显缺乏本土食草动物压力以及强烈的四分孢子体偏向。重要的是，它正在对PMNM具有文化和生态价值的珊瑚礁产生负面影响。这种假定入侵物种的地理起源未知，除了PMNM之外，没有该物种在其他任何地方出现的公开报告。夏威夷位于太平洋中部，这使得 有广泛的潜在起源地。该属内的分类学模糊性以及与采样相关的挑战，使得有必要制定一套范围更窄的搜索地点和有效的搜索策略，以在PMNM之外检测到该物种。附着在漂浮碎片上是 进入PMNM的一种潜在引入途径，一个海洋学模型被用于确定2000年至2015年期间该途径最可能的源地，包括西太平洋的日本、约翰斯顿环礁、中太平洋的莱恩群岛（包括帕尔米拉环礁）以及东太平洋的克利珀顿环礁和加拉帕戈斯群岛。我们使用了一种最近开发并经过验证的用于从三个感兴趣区域检测 的环境DNA检测方法来筛查 ，但没有样本检测呈阳性。我们提供了一个使用水下调查、显微镜检查和DNA条形码技术来调查环境DNA现场阳性检测结果的框架。还介绍了一项针对保存在全球植物标本馆中的标本的平行采样工作，但未检测到任何结果。全球植物标本馆中仍有几个 物种有待测序。确定 的原生范围是关键的一步，这将有助于评估其进化生态学以及可能发生的任何变化，这些变化促进了其假定的入侵和随后的扩散，为制定缓解策略以保护PMNM免受进一步风险提供至关重要的见解。
