The Bitan Dam's unique three-row, four-bend fishway effectively creates a smooth ecological corridor for various fish species to migrate. The clear waters of Xindian River not only provide sufficient dissolved oxygen for fish survival but also facilitate the upstream migration of many migratory species. Recently, a significant presence of the sensitive and precious Japanese Bullhead Shark (also known as the monkfish) has been reported, marking its third consecutive year of sightings, showcasing the ecological benefits of the Bitan Dam.

Director of the Water Resources Bureau, Song Deren, stated that underwater cameras have captured rare footage of schools of Japanese Bullhead Sharks. Observers are invited to witness these adorable creatures as they traverse the fishway through observation windows. This not only adds another ecological record to the fishway but also proves the overall improvement of the Xindian River's aquatic environment and validates the fishway's functionality in facilitating the migration of various fish species.

Ecological survey teams noted that the Japanese Bullhead Shark, which migrates between rivers and seas, is more common in eastern Taiwan and less so in the west. Their presence indicates the high dissolved oxygen levels in the river, signifying that the upstream water quality of Xindian River is excellent. In 2010, the Environmental Protection Administration announced that the Japanese Bullhead Shark, thought to be extinct for over 20 years, had reappeared in Bitan, confirming significant improvements in the quality of the freshwater ecosystem. Furthermore, during construction in May 2022, multiple Japanese Bullhead Sharks were spotted migrating upstream, showing interesting behaviors of climbing and feeding on algae along smooth surfaces. Thanks to their unique suction cup-like pectoral fins, they can easily climb up smooth surfaces, making waterfalls no obstacle for them.

The 132-meter-long fishway at Bitan Dam, operational since August 2023, is about to enter its third year. Initially, it was designed as an ecological compensation strategy, but its successful construction has reconnected the fragmented ecological corridor of Xindian River after 46 years. A total of 36 native fish species have utilized the fishway to migrate upstream. The Bitan Dam fishway has evolved from a mere water facility into an important ecological milestone, fulfilling the 'four-in-one' goals of water resources, tourism, ecology, and environmental education, creating a diverse and inclusive aquatic environment.