Finless Porpoise Conservation
Have You Heard of the Finless Porpoise, Korea's Native Dolphin?
Every finless porpoise cared for at SEA LIFE Busan Aquarium has a heartbreaking story. They were accidentally caught in fixed fishing nets used for commercial fishing, leaving them unable to escape. Some became stranded after losing their strength, while others were rescued with injuries sustained as they struggled to break free from the nets. Fortunately, after receiving dedicated care and recovering their health at SEA LIFE Busan Aquarium, they are safely returned to the ocean.
The finless porpoise belongs to the porpoise family and is a small marine mammal measuring approximately 1.5–1.9 metres in length and weighing up to 45 kilograms. It is one of the smaller cetaceans and is easily recognised by its rounded head and the absence of a beak. As its English name, Finless Porpoise, suggests, its most distinctive characteristic is that it has no dorsal fin, unlike most other whales and dolphins. It inhabits the warm coastal waters and freshwater regions of the Indo-Pacific, with the waters around Korea's West Sea and South Sea known as one of its largest habitats. The finless porpoise has long been an important part of Korea's marine ecosystem and was even described in Jasan Eobo, a renowned marine life encyclopedia written by Jeong Yak-yong during the Joseon Dynasty, as "a mermaid resembling a human."
Today, however, the finless porpoise faces serious threats to its survival. Although it has rarely been hunted directly, dozens are accidentally caught and killed in fishing nets every day as bycatch. Some are even illegally sold in markets after being falsely labelled as minke whale meat.
Discover how SEA LIFE Busan Aquarium is helping protect the finless porpoise through rescue, treatment, rehabilitation, and release back into the wild.
1. Rescue
A Rapid Response for Finless Porpoises in Need
Finless porpoises often become trapped in fishing nets while following schools of fish, and many suffer serious injuries as they struggle to escape. As soon as a report is received from local fishermen or the Korea Coast Guard, SEA LIFE Busan Aquarium works together with the Cetacean Research Institute to respond at the scene.
After safely rescuing the stranded animal, its condition is assessed as the highest priority. If the porpoise is healthy enough, it is released back into the ocean immediately. If intensive care is required, it is urgently transported to a government-designated marine animal rescue and treatment centre for specialised care.
2. Treatment
Specialist Care for a Healthy Recovery
Finless porpoises transported to SEA LIFE Busan Aquarium, a designated marine animal rescue and treatment centre, receive comprehensive health assessments under the care of veterinarians and marine animal specialists. Blood tests, diagnostic imaging, and endoscopic examinations are conducted to assess external injuries and internal conditions. Based on the results, each animal receives individualised treatment, including wound care, infection management, fluid therapy, and medication.
Minimising stress is the highest priority throughout the treatment process. Each porpoise is closely monitored and cared for around the clock until it is able to feed independently and maintain a stable physiological condition.
3. Rehabilitation
Preparing for a Return to the Ocean
Once a finless porpoise has recovered its health, it begins the rehabilitation process in preparation for its return to the wild. Rehabilitation is not only about physical recovery—it is about restoring the skills needed to survive independently in its natural habitat. Human interaction is kept to a minimum to preserve natural behaviours, while the porpoise is cared for in an environment that closely resembles its natural habitat, allowing it to readapt to life in the ocean.
The porpoise is then transferred to a sea pen in an area similar to its original habitat, where it undergoes approximately one month of rehabilitation. During this period, it learns to hunt live prey, rebuilds its strength and survival skills through natural feeding and regular exercise, and gradually regains the ability to live independently. Throughout the rehabilitation period, aquarists closely monitor the porpoise's behaviour and overall health to assess its readiness for release back into the wild.
4. Release
Returning Home to the Ocean
After approximately one month of rehabilitation, a final assessment is carried out to determine whether the finless porpoise is ready for release. Its overall health, blubber thickness, seasonal conditions, and sea temperature are carefully evaluated. Before release, the porpoise must also demonstrate that it can successfully hunt live prey on its own.
Once all assessment criteria have been met, the net of the sea pen used during rehabilitation is opened to minimise stress, allowing the porpoise to swim back into the open ocean at its own pace. Watching it return safely to the wild marks the culmination of our conservation efforts.
| Year | Rescue Location | Rescue & Treatment | Notes |
| 2003 | Namhae, Gyeongsangnam-do | A bycaught finless porpoise was transferred to Busan Aquarium for treatment before being transferred to 63 SeaWorld. | - |
| 2011 | Tongyeong, Gyeongsangnam-do | A finless porpoise entangled in a fixed fishing net was rescued, treated, and released. | Released in July 2013 |
| 2012 | Isudo, Geoje | A finless porpoise entangled in a fixed fishing net was rescued and immediately released after examination, as no injuries were found. | - |
| 2013 | Isudo, Geoje | A finless porpoise entangled in a fixed fishing net was rescued, treated, and released. | Released in October 2014 |
| 2014 | Isudo, Geoje | A finless porpoise was rescued from a fixed fishing net but later died from inflammation caused by injuries sustained during the entanglement. | - |
| Gijang, Busan | A finless porpoise entangled in a fixed fishing net was rescued, treated, and released. | Released in October 2015 | |
| 2016 | Neungpo, Geoje, Gyeongsangnam-do | A finless porpoise entangled in a fixed fishing net was rescued and treated. | Released in February 2017 |
| Sibang Village, Geoje, Gyeongsangnam-do | A stranded finless porpoise was found after being washed ashore and guided back to deeper waters before being released. | Released at the rescue site |
