Researchers compared differences in the genes inherited by both parents and those inherited only from mothers to better understand migration differences between males and females. However, this study found that these reef manta rays stay close to home and rarely cross the deep channels between islands. Reef manta rays are strong swimmers and could easily travel the tens of miles to different islands. Each island may need separate management strategies to ensure the rays’ long-term stability. Small and isolated animal populations are vulnerable to disease and extinction.

Their work reveals that Hawaiʻi Island and Maui Nui populations are made up of only a few hundred individuals each and should be considered distinct and separate. The researchers used genome scans to investigate population differences between reef manta rays of Hawaiʻi Island and Maui Nui (the four-island complex of Maui, Molokaʻi, Lānaʻi, and Kahoʻolawe). The results were published in BMC Ecology and Evolution. A team of researchers from NOAA’s Pacific Islands Fisheries Science Center, the Hawai‘i Association for Marine Education and Research, and the University of Miami conducted the first genetic study of reef manta rays in Hawaiʻi. New research shows that manta rays in Hawaiʻi live in isolated, island-specific, and genetically distinct populations.

Pacific manta ray