From time to time, we get asked about sharks in the Galapagos Islands and the types of sharks that visitors to the national park might expect to see. One shark species that may sometimes be observed in the archipelago is the tiger shark. The Latin name for tiger shark is Galeocerdo cuvier. While they are not endemic to the Galapagos Islands, they are regular visitors to the waters around the islands. Let us look at how to recognize tiger sharks and better understand their behavior, where to see them and the threats that they face.
Tiger sharks are very distinctive to look at when compared with other species in the shark family. They have vertical dark strips that are similar to those of a tiger, running down the top of their bodies. The head shape is also very recognizable. The tiger shark’s head is blunt and square shaped. Their teeth are curved and serrated and they have very large eyes.
The dark stripes on the back of the tiger shark tend to fade over time in older individuals. Younger tiger sharks have dark blotches rather than stripes and their coloring is often blue or green gray through to black looking.
Tiger sharks are among the largest types of sharks. When they are born, tiger sharks tend to be between around 1 to 1.5 feet (51-76 centimeters in length. When fully grown, in length, they vary from 10 to 14 feet (325 to 425 centimeters). Weight when fully mature is generally somewhere between 850 to 1,400 pounds (385-635 kilograms).
The Galapagos Islands offers a good source of food for tiger sharks, which is a key reason they may be observed in the archipelago from time to time. Fish diversity attracts this species to the islands. They are predators at the top of the food chain, and tiger sharks in the Galapagos Islands seem to particularly like eating green sea turtles. They may very often be found staying near to green turtle nesting sites for ease of food access. Aside from sea turtles they will also eat other shark species, fur seals, fish, sea birds, sea lions and even dead whales.
While the more mature individuals tend to hunt on shorelines, juveniles and younger tiger sharks are bottom feeders, most active at night. They are excellent hunters in the dark, using electroreceptors found on their snouts to pinpoint and hunt prey. Some evidence points to tiger sharks using group hunting techniques.
Tiger sharks in the Galapagos use the seas around the islands for nursing and rearing their young. Mothers birth juveniles that are live.
There is still more than can be learned about tiger shark behavior. This is one of the reasons that some scientists from the Charles Darwin Foundation have been tagging sharks to find out more about their movement, biology, and populations. The aim is that through gaining a better understanding of their behavior and movements, decisions can be made to better protect these graceful beasts. The tracking program tracked one individual all the way from the Galapagos Islands, nearly 700 miles north to a site close to the Cocos Islands off Costa Rica! The study has also shown that some tiger sharks stay in the Galapagos Marine Reserve for a lot of their time, even more than 90% of the time in some cases. Other individuals may reside in the reserve for a long time but also visit deeper waters beyond the reserve at times as well.
Seeing a tiger shark while on Galapagos Island cruises or Galapagos land-based trips is a relatively uncommon occurrence, but it does happen sometimes. Most commonly they may be seen by divers on liveaboard diving trips in the direction of Darwin and Wolf Islands. These are tiny, uninhabited islands that can be found to the north / north west of Isabela Island. Wolf Island is approximately 100 miles away from Isabela Island and both are very remote, outlying islands. No cruises go out to these islands, only dive ships.
Another location in the Galapagos Islands where the tiger shark can sometimes be seen is on the Itabaca Channel. This runs between Santa Cruz Island and Baltra Island much more centrally in the archipelago when compared with Darwin and Wolf Islands. They may also sometimes be seen to the south of Isabela Island.
There is no guarantee of seeing a tiger shark while on a visit to the Galapagos Islands. This is because the species is migratory and so is not always present in the area. That makes getting to see a tiger shark a very lucky experience. The most likely time of the year to spot this species is during the warm and wet season, and particularly between the months of February and June. They can be present during other months but there are usually higher numbers in these months. This is in part due to the mating season of green sea turtles.
The tiger shark has a conservation status of near threatened. Despite the fact that it is at the top of the food chain, it faces a variety of threats to its survival.
A key threat to this species is harvesting. Tiger sharks have several elements that they are harvested for. These include their flesh (meat), their skin and their fins. Fins are thought of as a delicacy in some countries. Tiger livers are stores for a lot of vitamin A, which some people harvest to produce vitamin oil. Trophy hunting is yet another unfortunate and disappointing reason why this species is under threat.
Sometimes tiger sharks also get caught up in fisheries or being caught by fishers who are out catching other species. Tiger sharks can get snared in nets, or on long lines that were not designed to catch them. A positive, is that if caught on a long line, research shows that up to 95% of tiger sharks can survive when released. Trawling is a method of fishing that can put sharks such as tiger sharks at risk.
Tiger sharks are also threatened due to overfishing. This can lead to their food sources being depleted.
Many people worry about shark attacks and fear that they are threatened with such an attack. The reality is that these graceful creatures are much more at threat from humans than humans are of them. It is estimated that 80-100 million sharks are killed by humans each year. Yet fewer than 50 people were attacked unprovoked across the globe in 2024. Only around 70 are injured by a shark every year.
