Detrimental effects of sediment on attachment, survival and growth of the brown alga Sargassum thunbergii in early life stages

Abstract

Sediment loading by human activities has increased in recent years and sedimentation in coastal areas is problematic because it removes seaweed forests. In this study, we examined the effects of different sediment quantities (0, 2, 4, and 6 mg cm(-2)) and particles sizes (<100, 100-250, and 250-600 mu m) on zygote attachment, and germling survival and growth of Sargassum thunbergii, an economically and ecologically important species. Zygote attachment was negatively correlated with increased sediment quantities. However, it was not significantly different among sediment particle sizes. In addition, survival and growth of germlings were significantly inhibited by increased sediment quantity. Smaller particle size (< 100 mu m) had greater negative impact on the survival and growth than bigger ones. Results of the present study suggest that early development of S. thunbergii is significantly inhibited by sediment. This might be a vital factor that results in forest depletion in Korea.