An overload of nutrients, called eutrophication (Greek for "good-nutrition"), can be harmful to estuaries. This phenomenon is also referred to as "over-enrichment," or "nutrient pollution". Students will investigate the range of conditions that selected animal and plant species need to survive in an estuary and will model estuaries, artificially enriching freshwater and saltwater samples with different amounts of nutrients and observing the growth of algae over several weeks.