Final answer:
The removal of starfish from an ecosystem can lead to population explosions of their prey, such as mussels and sea urchins, causing a cascade of negative effects throughout the food web. As a keystone species, their absence can disrupt fisheries, economies, and biodiversity, potentially leading to the collapse of the marine ecosystem.
Step-by-step explanation:
If starfish were removed from an ecosystem, particularly a marine ecosystem like a coral reef, there would likely be significant ecological consequences. Starfish often function as keystone species, meaning they have a disproportionate effect on their environment relative to their abundance. For instance, sea stars commonly prey on mussels and sea urchins which, in the absence of this predation, may experience population explosions. These unchecked populations can overgraze and decimate algal populations, leading to a loss of biodiversity. Other species that rely on the algae for food or habitat could decline or disappear, causing a cascade of effects throughout the food web.
This disruption may also affect fishery dynamics. With the reduction in species complexity and loss of habitat, harvested fish populations could crash, adversely affecting human economies and food sources. Over time, the entire aquatic system could be compromised as a source of ecological services, sustenance, and employment.