82 Zebra Shark Pups Released in Indonesia's Marine Sanctuary

An international consortium called ReShark has released 82 captive-bred zebra shark pups into a 46,000 square kilometer sanctuary in Raja Ampat, Indonesia. This project is the first attempt to rewild a species that has seen its numbers collapse due to habitat loss and overfishing. For these endangered sharks, the release into the protected waters of the shark and manta ray sanctuary is a vital step toward recovery.

Known for their distinctive stripes, zebra sharks—or Indo-Pacific leopard sharks—typically inhabit shallow coastal waters. While rewilding is more common for land animals, this marine initiative follows three years of preparation by a network of 60 aquariums across 15 countries. Together, they have shown that it is possible to breed these sharks in captivity specifically for release into their natural habitat.

Before their release, the pups were raised in controlled environments by specialists known as "shark nannies" who monitored their health and development. Once the sharks reached about one meter in length, they were moved to the sanctuary in Raja Ampat. They have already begun foraging on their own within the protected zone. Mark Erdmann, executive director of ReShark, noted the urgency of the work, pointing out that by 2019, the adult zebra shark population in Raja Ampat had dwindled to an estimated 20 individuals.

Beyond restoring the population, the project works with local communities to encourage sustainable fishing and explain the ecological role these sharks play. If these individuals successfully reproduce, the model could be applied to other threatened shark species around the world. ReShark is currently using satellite tags to track the pups, gathering data on how they adapt and behave in the wild. Full results from the study are expected by 2028, providing a clearer picture of how this approach might help preserve marine biodiversity.