As I am doing more research on coral reefs and how the location of the reefs affects their survival, I am learning that humans are the most pressing problem to their survival. Humans are directly, or indirectly causing death of coral reefs around the world. One of the ways humans are killing reefs is by overfishing. Overfishing changes the food web of that particular reef. As a result, the structure of the reef changes as well. The structure changes because fish, especially parrotfish, have specific duties that keep the reef healthy and resilient. Parrotfish and other fish eat the macroalgal that are trying to grow on the coral, munch on dead and live coral which will make it easier for new coral to grow and flourish, and transport sediments and nutrients to different parts of the reef and elsewhere. These duties are important for coral to have quick recovery time when facing a disaster. This journal article is about how strongly does human population and their fishing of parrotfish affects coral reefs. These researchers did a natural experiment using detach observation and reports of acts and behaviours to see the impact humans have on 18 coral reefs from the Indian Ocean to Tahiti. Human population differs from zero and reefs protected from fishing to overpopulated cities that overfish. Surprisingly, they found no correlation between the overfishing of parrotfish and human population. Also, that there is a strong relationship between human population and the population structure of reef fish because humans want the big parrotfish so then the smaller parrotfish populate the reefs. Which means coral reefs are sensitive to human activity regarding bioerosion and coral predation but not sensitive with eating dead and live coral, and transporting sediments. Overall, human activity indirectly affects coral reefs.

Bellwood, D. R., Hoey, A. S., and Hughes, T. P. (2012) Human activity selectively impacts the ecosystem roles of parrotfish on coral reefs. Proceedings: Biological Sciences 279(1733): 1621-1629.