Gradient experiment reveals physiological stress from heavy metal zinc on the economically valuable seaweed Sargassum fusiforme.

Zn is a common heavy metal pollutant in water bodies and accounts for the largest proportion of heavy metal pollutants in many rivers entering the sea. This study investigated the growth and physiological response characteristics of Sargassum fusiforme under different divalent Zn ion concentration gradients. We observed that low concentration Zn treatment (<2 mg L) exerted no significant effect on the growth rate, photosynthesis, and nitrogen metabolism-related indicators of S.