A Comprehensive Assessment of Heavy Metal Contamination in Chinese Lake Sediments and Submerged Macrophyte Responses: Multi‐Scale Impacts, Accumulation Capacity and Tolerance Mechanisms

ABSTRACT Although considerable research has examined the effects of heavy metals on submerged macrophytes, a comprehensive review addressing individual, population and community perspectives is lacking. This review first summarises the current status of heavy metal contamination in aquatic sediments in China. It then provides an in‐depth analysis of heavy metal uptake, transport and accumulation in submerged macrophytes, as well as their broader ecological impacts across multiple scales. Additionally, we investigate the metal accumulation capacities of submerged macrophytes and examine their tolerance mechanisms. The findings underscore the severe contamination of aquatic ecosystems by heavy metals in sediments and reveal their multi‐scale impacts on submerged macrophytes. At the individual level, heavy metals disrupt cellular functions, impairing photosynthesis, respiration and overall metabolic balance. Over time, these effects may influence population dynamics. Species‐specific differences were observed in heavy metal accumulation and tolerance mechanisms, including variations in metal sequestration, antioxidant activation and phytochelatin production. Consequently, heavy metal pollution may further alter the submerged macrophyte community composition. This study identifies heavy metal pollution as a critical global issue, posing threats to submerged macrophytes across multiple ecological levels. Understanding its role in macrophyte decline is essential for ecosystem conservation. Additionally, our findings offer valuable insights into selecting heavy metal‐tolerant species to facilitate both macrophyte recovery and sediment remediation, thereby contributing to the sustainable management of aquatic ecosystems.