Research on the application of the Autonomous Reef Monitoring Structures (ARMS) for the change of marine ecosystem and biodiversity diagnosis in Jeju Island

Abstract

Increasing seawater temperatures driven by climate change have negative impacts on marine biodiversity. Jeju Island has been suggested as an area capable of supporting high biodiversity, due to its geographical position and the different water masses influencing the marine environment around the island. Jeju is located within temperate latitudes, but borders to environmental changes, providing an ideal testbed for assessments on life under rapid climate change. However, a major limitation of monitoring programs is the difficulty to compare and quantify results generated by different methods. The MarineGEO program from the Smithsonian Institution's Tennenbaum Marine Observatories Network (TMON) developed a quantitative, standardized method of sampling monitoring data, called Autonomous Reef Monitoring Structures (ARMS) to overcome these problems. This is the first report to provide an inventory of marine biodiversity from Jeju waters in Korea using ARMS. We deployed ARMS units in Jeju (Kangjung, Bomok, and Seongsan) in 2018. After 12 months, the ARMS units were retrieved and a taxonomic analysis determining the marine biodiversity conducted. A total of 191 marine species were identified from ARMS; 109 species from Gangjung, 106 species from Bomok, and 91 species from Seongsan. The most abundant phylum was arthropods, followed by mollusks, annelids, and echinoderms. So far, we found two new species of Osctracoda and one unrecorded species of gastropod from the ARMS units. We expect this baseline data will provide further information to detect “climate refugees”, i.e. newly extended species due to climate change, as well as species new to science of understudied taxa. These “climate refugees“ would disturb marine ecosystems as they compete with indigenous marine organisms. Besides investigating changes in marine ecosystems caused by climate change, and detecting invasive marine species, this standardized monitoring method (ARMS) is applied to understand the role of biodiversity in sustaining resilient coastal marine ecosystems under climate threat.