USGS scientists across the nation are working to understand, predict and prevent impacts from harmful algal blooms to people and wildlife. Algae. If you’ve ever visited a pond, cleaned a fish tank, or eaten sushi, you’ve likely encountered some of these water-living, plant-like organisms. Algae come in many shapes and sizes and play important roles in ecosystems. For one, they make energy from sunlight through photosynthesis, which leads to them being the base of the food web in marine and freshwater communities. … However, unfortunately, an algal bloom can also become a runaway train. When an algal bloom “runs away” from ecological checks and balances, it can create negative consequences and if it does, it’s called a harmful algal bloom. For instance, algal blooms can cause water bodies to become anoxic, meaning they have little-to-no oxygen. That’s a problem for fish and invertebrates, like shrimp, that rely on dissolved oxygen in the water…