In Chile, a marine reserve led to a rapid increase in adults and young of an overfished species, restored key ecological interactions, and provided useful information for management.

 

Before the marine reserve was established at Las Cruces, Chile, a large, predatory snail, called the Chilean abalone, or loco, had become rare because of intensive harvesting. In the absence of locos, nearly 100% of the shore was dominated by mussels, loco's favorite prey.

 

Exclusion of human harvesting greatly changed the ecological community. After establishment of the marine reserve in 1982, locos quickly became abundant and grew much bigger in the reserve. Only 4 years later, their mussel prey covered less than 5% of the shore. As mussels decreased, locos competed for fewer prey, leading to a decline in locos.