What type of pollutants can accumulate in aquatic organisms?

Heavy metals are a significant concern when it comes to contaminants that can accumulate in aquatic organisms. They have the unique ability to bind to tissues and biomolecules within these organisms, leading to bioaccumulation. This accumulation occurs because metals like mercury, lead, or cadmium are persistent in the environment and cannot be easily broken down. As aquatic organisms ingest these metals through water or food sources, concentrations can build up in their bodies over time, often resulting in higher levels than those present in the surrounding water.

This process poses serious risks to both the organisms themselves and, subsequently, to predators in the food chain, including humans. Understanding the implications of heavy metal accumulation is vital for assessing the health of aquatic ecosystems and ensuring that water quality standards protect both wildlife and human health. Other options, while they can affect aquatic organisms, don't generally lead to the same degree of accumulation as heavy metals. For example, bacteria can cause harm but are typically not bioaccumulated to hazardous levels. Organic matter is part of the natural ecosystem and is decomposed rather than accumulated, while microplastics are ingested by organisms but do not "accumulate" in the same way as heavy metals.