Effects of pH and Salinity on the Cultivated Brown Alga Sargassum fulvellum and Associated Animals

doi:2006.21.3.317

Algae > Volume 21(3); 2006 > Article

Algae 2006;21(3): 317-321. doi: https://doi.org/10.4490/algae.2006.21.3.317

Eun Kyoung Hwang¹^*, Dong Soo Ha¹, Jae Min Baek¹, Mi Young Wee² and Chan Sun Park²

¹Seaweed Research Center, NFRDI, Jeonnam 530-831, Korea
²Department of Marine Resources, Mokpo National University, Jeonnam 534-729, Korea

ABSTRACT

The effects pH and salinity on the brown alga Sargassum fulvellum were investigated in the context of the removal of two major associated animals, Caprella scaura and Gammaropsis utinomi. Optimum quantum yield (Fv/Fm) of S. fulvellum was also examined in the same experimental conditions as an index of stress. Experiments on pH and salinity tolerances of the two animal species indicated that mortality was more than 80% at extremes of pH (2, 3, 4, 10, 11, 12) and salinity (0, 3.5, 7, 10, 44 psu) after a 5 min treatment. Lethal time (LT50) from pH 2 to pH 4 was less than 90 sec in C. scaura, and less than 70 sec in G. utinomi. From 0 to 10 psu, LT50 was less than 20 sec in C. scaura and less than 60 sec in G. utinomi. The quantum yield of S. fulvellum was not significantly different from controls within the pH range 4~10, and within the salinity range of 7-40 psu. When exposed to pH and salinity conditions outside these ranges, the effect of these factors on the removal of two animal species was higher, but quantum yield was highly reduced. These results indicate that the optimal conditions for removing the animal species without affecting optimum quantum yield were pH 4-10, and salinities 7-10 psu and 44 psu.

Key words: Caprella, Gammaropsis, pH, Salinity, Sargassum cultivation