RESUMEN
The present investigation was aimed to characterize the Ulva blooms and to identify the probable sources for Ulva blooms along the Jeju Island coast for pertinent control measures. Algal isotope signatures (δ13C, δ15N and δ18O) and tissue nitrogen and carbon were analyzed to map nutrient sources around the Jeju coastal areas. The algal δ13C values were ranged from -20.52 to -4.39, while δ15N and δ18O values ranged from 4.26 to 8.29 and 12.80-17.34, respectively. Moreover, site-specific significant differences were observed in algal stable isotope (δ13C, δ15N and δ18O) values. The bi-plot (δ15N vs δ18O) diagram indicated four dominant nitrogen sources along the Jeju coast, with 1) soil organic nitrogen mixed with livestock wastes (spring water samples and E), the 2) synthetic fertilizer input (A3 and B2), 3) sewage discharge (D1, D2 and I3) and 4) aquaculture waste (fish farm samples, A4, A5, B1, G and I2). Present findings revealed the different potential nitrogen sources for localized increase of algal growth along the Jeju coast. Finally, the present findings could be used as baseline data for efficient nutrient management to remediate Ulva blooms along Jeju coastal environment.
