What is a common effect of mercury in wastewater?

Mercury in wastewater is a significant environmental concern primarily because it can lead to bioaccumulation in aquatic organisms. When mercury enters water bodies, it is often converted into methylmercury, a highly toxic form that readily accumulates in the tissues of fish and other organisms. As smaller fish consume this toxic compound, it becomes concentrated along the food chain, leading to higher mercury levels in larger predatory fish. This accumulation poses serious health risks to wildlife and humans who consume these fish, making awareness of mercury pollution critical for both ecosystem health and public safety.

The other effects mentioned, such as algae growth or changes in fluorescence, do not directly address the most harmful consequence of mercury contamination in the aquatic ecosystem, which is the bioaccumulation that has lasting impacts on food webs and human health.