Trace metal spatial patterns and associated ecological toxic effects on phytoplankton in Qinghai–Tibet Plateau lake systems along with environmental gradients

Abstract

Trace metal concentrations in lake systems may inhibit or promote phytoplankton growth and associated community structure factors, subsequently affecting their gross primary production (GPP). Accordingly, this study investigates trace metals and their associated effects on community structure in Qinghai–Tibet Plateau (QTP) lake systems along with elevation and salinity gradients. Results show that Trace metal pollution was found to occur in greater than 65% of QTP lake systems. Saline lake systems were the most heavily polluted, saltwater lake systems were the most moderately or slightly polluted, and freshwater lake systems were unpolluted. Trace metal concentrations decreased and phytoplankton biomass increased as altitude increased. Conversely, trace metal concentrations increased as salinity levels increased, but phytoplankton biomass decreased. High trace metal concentrations were significantly and negatively correlated to phytoplankton biomass. This also indicates that high trace metal concentrations are highly toxic and inhibit physiological, biochemical, and photosynthetic phytoplankton growth processes.