The concentration of heavy metals in contaminated water can significantly affect the growth of aquatic plants. Heavy metals, such as lead, mercury, cadmium, and copper, can be toxic to plants at high concentrations, leading to various physiological and biochemical changes that can inhibit their growth and development. The impact of heavy metals on aquatic plants can be summarized as follows:1. Inhibition of photosynthesis: Heavy metals can interfere with the photosynthetic process by binding to essential components of the photosynthetic machinery, such as chlorophyll and photosystem proteins. This can lead to a reduction in photosynthetic efficiency, which in turn affects the plant's ability to produce energy and organic compounds necessary for growth.2. Disruption of nutrient uptake: Heavy metals can compete with essential nutrients for uptake by plant roots, leading to nutrient deficiencies. For example, heavy metals like lead and cadmium can interfere with the uptake of essential nutrients like calcium, magnesium, and iron, which are crucial for plant growth and development.3. Oxidative stress: Heavy metals can induce the production of reactive oxygen species ROS in plant cells, which can cause oxidative stress and damage cellular components, including lipids, proteins, and DNA. This can lead to a decline in plant growth and even cell death.4. Alteration of enzyme activity: Heavy metals can bind to and inhibit the activity of various enzymes involved in essential metabolic processes, such as respiration, nitrogen assimilation, and protein synthesis. This can negatively affect plant growth and development.5. Morphological changes: High concentrations of heavy metals can cause visible morphological changes in aquatic plants, such as reduced root and shoot growth, leaf chlorosis yellowing , and necrosis tissue death .6. Reduction in reproductive capacity: Heavy metal toxicity can also affect the reproductive capacity of aquatic plants by causing a decline in seed germination, pollen viability, and seedling growth.To mitigate the effects of heavy metals on aquatic plants, it is essential to monitor and manage the concentrations of these contaminants in water bodies. This can be achieved through regular water quality testing, implementing pollution control measures, and using phytoremediation techniques, where specific plants are used to remove heavy metals from contaminated water.