Refer to Infographic 8

Essay

Refer to Infographic 8.Each year a "dead zone" appears in the Gulf of Mexico when oxygen levels in the water drop to levels insufficient to support the fish and shrimp that live there.The drop-in oxygen is due to the decomposition of photosynthetic phytoplankton that grow in huge numbers,die,and sink to the bottom; they are then decomposed by bacteria that use up oxygen in the process.Use the infographic to describe what the limiting factor to phytoplankton normally is and how that factor is removed each spring when rains wash runoff from Midwestern farm fields into rivers that empty into the Gulf.What could be done to help prevent this from occurring?