Physiological and Biochemical Responses of the Green Tide-Forming Algae, <i>Ulva</i> Species, under Different Nutrient Conditions on Jeju Island, Korea
2024
Kyeonglim Moon | Sun Kyeong Choi | Seong Bin Ham | Young Baek Son | Yun Hee Kang | Sang Rul Park
In this study, we investigated the physiological and biochemical responses of <i>Ulva</i> species to variation in nutrient availability. Sampling was conducted at two sites on Jeju Island, Korea, namely, Handong, which is close to seven intensive land-based fish farms, and Hado, which has no apparent nearby nutrient sources. We examined the water column nutrient concentrations, nitrate reductase (NR) activity, nitrate uptake efficiency, tissue C, N, and P content, and stable isotope ratios of <i>Ulva</i> species. Water column NH<sub>4</sub><sup>+</sup>, NO<sub>3</sub><sup>−</sup> + NO<sub>2</sub><sup>−</sup>, and PO<sub>4</sub><sup>3−</sup> concentrations were significantly higher at Handong than at Hado. NR activity and tissue N content of <i>Ulva</i> species were significantly higher at Handong than at Hado. Notably, nitrate uptake efficiency was inversely proportional to NR activity and tissue N content. The physiological and biochemical responses of <i>Ulva</i> species were closely related to dissolved inorganic nitrogen, which stimulates <i>Ulva</i> species to regulate growth. Additionally, the δ<sup>15</sup>N values of <i>Ulva</i> tissues at both sites were within the previously reported range for fresh groundwater. Therefore, the main nitrogen source for <i>Ulva</i> growth may be submerged groundwater with high nutrient concentrations. Our results provide invaluable information for estimating dissolved inorganic nitrogen levels in water, which may facilitate development of management policies.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by Directory of Open Access Journals