Interactions between sharks and humans in Costa Rican waters are extremely rare, particularly when compared to other global hotspots. Official data collected by international marine organizations provides the clearest picture of the frequency of these encounters. By examining the historical record and classifying the nature of these incidents, a less sensationalized picture emerges. This information provides context on the rarity of these events, the specific locations where they happen, and the species involved.
The Historical Record and Official Statistics
Documented shark incidents in Costa Rica are remarkably low, with official data tracking fewer than 20 total incidents. The International Shark Attack File (ISAF), which tracks worldwide statistics, confirms this low frequency across the country’s extensive coastline. These incidents are categorized to distinguish between two main types of encounters: unprovoked and provoked.
An unprovoked incident is defined as a bite on a live human in the shark’s natural habitat without any human initiation. The vast majority of confirmed incidents in Costa Rica fall into this unprovoked category. A provoked incident occurs when a human instigates the encounter, such as by attempting to feed, touch, or handle a shark, or by being bitten while spearfishing.
While the number of total incidents is small, the rate of fatal encounters has historically been reported as higher than the global average. This is skewed by the extremely low total count, as one or two severe cases can dramatically alter the statistical fatality percentage. Overall, the probability of an encounter remains minuscule for anyone entering the water.
Geographical Distribution and Shark Habitats
The geographical distribution of shark incidents in Costa Rica is heavily concentrated on the Pacific coast, with the Caribbean coast having a nearly negligible recorded history. The Pacific coastline features the turbid river mouths and surf breaks where most near-shore incidents have occurred. The warm, shallow waters of the Pacific side, particularly in the Guanacaste Province, are the primary areas for such activity.
The most notable location for shark-human interactions is the remote Isla del Coco, or Cocos Island, a National Park situated over 300 miles off the Pacific mainland. This oceanic island is a destination for deep-water scuba diving, which places humans in close proximity to large pelagic sharks. The island’s unique marine ecosystem attracts large aggregations of sharks that are accustomed to divers.
On the Pacific mainland, many incidents have been reported near river mouths and estuaries, such as those found near Playa Grande and Playa Tamarindo. These areas feature lower visibility and brackish water, which are habitat preferences for specific species. The country’s Caribbean coast sees significantly less offshore diving and appears to host fewer of the species historically associated with human encounters.
Species Commonly Associated with Incidents
Two species primarily account for the documented incidents in Costa Rican waters: the Bull Shark (Carcharhinus leucas) and the Tiger Shark (Galeocerdo cuvier). Bull Sharks are frequently found along the mainland Pacific coast, often in the shallow, warm waters near estuaries and river mouths. Their ability to tolerate fresh water allows them to venture into brackish environments where they may encounter surfers and swimmers.
Bull Sharks are known for their robust build and opportunistic feeding behavior in these turbid, coastal zones, contributing to their involvement in near-shore incidents. They utilize the sheltered conditions of river mouths as nursery grounds, making them a common presence in areas frequented by coastal water users. Incidents involving this species have historically been linked to surfing activity.
Tiger Sharks are the other species of concern, particularly in the deep-water environments surrounding Isla del Coco. These large, solitary predators are highly mobile and opportunistic feeders. The fatal 2017 incident at Cocos Island involved a Tiger Shark, highlighting the potential for serious interactions in this remote, diving-focused habitat. Tiger Sharks are drawn to the island’s abundance of prey.