Human Impact on the Ecosystem
Over the last 140 years, humans have had major impacts on the ecological structure of the aquatic ecosystem in Crater Lake. Humans added over 5 different species of trout and salmon to the lake in the 20th century. Of those species, only the Rainbow trout and Kokanee salmon were able to find niches and survive (ranger). Not only did we add fish, we were worried about them having an adequate food source, so freshwater shrimp were also stocked. Runoff from the national park lodge may cause some petroleum pollution, but it hasn't become significant.
In the 1940's, there was a large increase in the amount of visitors to the park(CLi). This came as a shock to the sewage system. There was a sewage leak into the park's drinking water that made over 100 employees sick. This was presumed to also have an effect on the lake down below. If the sewage leak had gotten into the lake, it would have affected the Biogeochemical Cycle of Nitrogen. The sewage rich in Nitrogen could have spiked growth in algae and phytoplankton, as well as spiked populations in zooplankton like Daphnia.
In the 1940's, there was a large increase in the amount of visitors to the park(CLi). This came as a shock to the sewage system. There was a sewage leak into the park's drinking water that made over 100 employees sick. This was presumed to also have an effect on the lake down below. If the sewage leak had gotten into the lake, it would have affected the Biogeochemical Cycle of Nitrogen. The sewage rich in Nitrogen could have spiked growth in algae and phytoplankton, as well as spiked populations in zooplankton like Daphnia.