When it comes to fish and the environment they live in, silicates can be a major concern. Silicate is an oxide of silicon that occurs naturally in many types of rocks, particularly granite and quartzite. When these rocks are exposed to water, they erode over time and release silicate into the surrounding environment. While silicates are not necessarily toxic to aquatic life on their own, they can cause harm when present in excessive amounts. High concentrations of silicates can lead to suspended particles forming clumps or “flocs” which can interfere with oxygen levels as well as create additional turbidity which blocks sunlight needed for photosynthesis by aquatic plants. Furthermore, high concentrations of suspended solids (including those from eroded rocks) will reduce the amount of food available for filter-feeding organisms such as mussels or fish larvae. As a result, long term exposure to excessive amounts of silicate could have serious effects on both the physical health and reproduction capacities of fishes living within affected environments.