December 17, 2024 — A red alga first found by University of Hawaiʻi at Mānoa researchers smothering coral reefs in Papahānaumokuākea Marine National Monument (PMNM) has been detected for the first time by the team outside of the marine monument and more than 2,000 miles away.
The research team detected DNA matching Chondria tumulosa in Majuro Atoll in the Republic of the Marshall Islands in the east-central Pacific Ocean. Papahānaumokuākea is a chain of islands and atolls that extends approximately 1,200 miles northwest of the main Hawaiian Islands in the northern Pacific.
“Our discovery in Majuro suggests that C. tumulosa may be more widespread than we previously thought. This could have significant implications for coral reef ecosystems across the Pacific, potentially requiring broader monitoring efforts and a more comprehensive understanding of the alga’s distribution and ecological impact,” said UH Mānoa School of Life Sciences graduate student Patrick Nichols.
A threat to coral reefs
First detected in 2016 and named in 2020 by UH researchers, C. tumulosa has earned a reputation for smothering coral reefs in PMNM, where it forms dense mats that blanket corals and other native organisms. Its mat-forming behavior, ability to spread rapidly, and unknown origin have posed significant challenges for reef conservation.
Until now, the alga had only been observed spreading throughout the three northwestern-most atolls of PMNM: first at Manawai (Pearl and Hermes), then Kuaihelani (Midway Atoll) and Hōlanikū (Kure Atoll). However, a new detection outside of Hawaiʻi caught the researchers by surprise.