Work

Physiological Responses and Functional Performance of Eucheumatoid Seaweeds Under Prolonged Low-Salinity Stress

Year: 2026

Type: article

Abstract: Low-salinity events caused by heavy rainfall and freshwater runoff pose significant environmental constraints on eucheumatoid seaweed mariculture in coastal areas. In this study, five eucheumatoid seaweeds, including three strains of Kappaphycus alvarezii (Hn-R, Hn-G, and Ma-R), Kappaphycus striatum, and Eucheuma denticulatum, were exposed to 22, 26, and 30 psu for 36 days. Growth performance, photosynthetic pigments, chlorophyll fluorescence parameters, oxidative damage, and antioxidant responses were determined. To compare the actual physiological performance of different seaweeds under each salinity condition, a functional performance score was calculated using membership function analysis based on relative growth rate, chlorophyll a, carotenoids, photosynthesis, and malondialdehyde. Low salinity generally reduced growth, photosynthetic pigment content, and photosystem II performance, while increasing malondialdehyde content and antioxidant-related parameters, indicating that prolonged low-salinity exposure induced both physiological inhibition and oxidative stress responses. At 22 psu, K. alvarezii Ma-R showed the strongest functional performance, followed by K. striatum and E. denticulatum. At 26 psu, E. denticulatum showed the strongest functional performance, followed by K. alvarezii Ma-R and K. striatum. These results indicate that eucheumatoid seaweeds differ in their functional performance under mild and more severe low-salinity tolerance, providing physiological evidence for selecting candidate eucheumatoid seaweeds for salinity-fluctuating coastal mariculture.

Source: Journal of Marine Science and Engineering

DOI: 10.3390/jmse14131193

Authors: Jianling Zhan, Zhenwei Mo, Fen Cheng, Xianming Tang, Hong Du, Qiong Wu

Institutions: Shantou University, Hainan Provincial Academy of Marine Fisheries and Aquaculture, Hainan University

Language: English

Topic: Marine and coastal plant biology

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Life below water, Zero hunger

Open Access status: gold

Estimated APC paid: $3,137