Here We Go ALGA-in
By: Alyssa Mincer, Seawords Associate Editor

Coral reefs are invaluable ecosystems, providing sustenance and habitats for an array of marine creatures. They are an essential component in fishery health, and act as barriers against the waves, preventing coastal erosion. Unfortunately, coral reefs are especially susceptible to a number of threats, with a major hazard being the presence of invasive species. Marine invasive species, which primarily inflict harm by outcompeting native species, are characterized by rapid growth rates and adaptability to various habitats. Generally, a species is considered invasive if it is a non-native resident within an ecosystem that harms endemic species. 1,200 miles from Oʻahu, researchers from the National Oceanic and Atmospheric Administration (NOAA) in the Northwestern Hawaiian Islands at Papahānaumokuākea Marine National Monument were shocked to discover an obscure species of red alga growing in small patches throughout the reefs. First noticed in 2016, the alga, which at the time was not ubiquitous throughout the reef, did not seem to pose a substantial threat to the health of the coral habitat. In the summer of 2019, upon returning to the same sites, divers noted a substantial increase in the unidentified alga, which exhibited characteristics similar to those of an invasive species; proliferous mats of the algae were spread thick upon thousands of square meters of coral reefs off of Pearl and Hermes Atoll, smothering the corals, altering the structure of the habitat. Alison Sherwood, a Professor of Botany and Interim Associate Dean of the College of Natural Sciences at the University of Hawaiʻi at Mānoa, quickly assumed the role as lead researcher on a study of the alga. Following examinations, scientists decided to name the species Chondria tumulosa. Despite the tendency of the alga to act like an invasive species, denoted by its unusually abrupt emergence and its subsequent spread throughout given habitats, scientists are unable to determine whether or not it is a native species, and are thus deeming it as a “nuisance alga.” If the alga was to advance outside of its current range, coral reefs would likely be substantially impacted. According to NOAA’s Deputy Superintendent of the Papahānaumokuākea Marine National Monument, Randall Kosaki, preventative measures must be taken in order to avoid the expansion of the alga both within the monument as well as to other regions. Divers conducting research on the alga are taking necessary precautions so they can safely gather more information on the red alga and steer clear of a potential ecological disaster for coral reefs down the line.