What was the outcome of removing starfish in the Paine manipulation experiment?

In the Paine manipulation experiment, the removal of starfish, which are considered a keystone species in intertidal ecosystems, led to a significant decline in species richness and diversity. Starfish feed on mussels, which compete with a variety of other species for space and resources. When starfish were removed, mussels were able to dominate the space and outcompete other organisms for resources, leading to a decrease in the overall diversity of the community. This highlighted the critical role that keystone species play in maintaining the structure and diversity of an ecosystem. The decline in species richness is a direct result of the competitive exclusion of less dominant species when predators are removed from the environment.