The main problem in Minamata bay is that the factory does not properly dispose of their mercury waste. This effects the organisms in the water which are eaten by the people who are also effected by large amounts of mercury. Mercury is a hazardous element that causes health issues such as pneumonia or extreme kidney damage. It also affects the habitats of the animals and bacteria living in the water near the factory. All this leads to a slowly decreased population of organisms and people.
This case study is a prime example of Bioaccumulation. This example displays how when a very small element or substance is released into an environment, the smallest organism ingests it accumulating a very small amount of said element. However, when this small organism is ingested along with many others by a larger organism, this element concentration grows. Exponentially, this leads to the top consumer, and in this case, the human, where the element has grown to such an amount that it is hazardous to the top consumers since it eats the most concentrated amount of said element, mercury.
Therefore, when the mercury waste infiltrated the fishing environment of Minamata, it created a cycle that slowly began to poison the people of Minamata due to bioaccumulation of the mercury.