Taijiang National Park is located in the southwest side of Taiwan. It is the first national wetland park in Taiwan. Its southern boundary is the Yanshui River and its northern boundary is the Jiudingshan Salt Pan. There are numerous important rivers in the local area, such as Tsengwen River, Luermen River and Qigu River. Numerous companion plants for coast wetlands grow around these rivers, such as black mangrove, lumnitzera, four-petaled mangrove and milky mangrove. The mangrove reserve at the estuary of Qigu River is a terrestrial wetland reserve belonging to Taijiang National Park. It is one of the few wetland reserves located in the sea area. It has an area of about 5.63 hectares.
The Taijiang National Park Headquarters entrusted experts and scholars to study the Qigu Lagoon for the research of lagoon waters. There are many fish species in this lagoon. It is estimated that there are 150 to 200 types of fish in this area. The dominant fish species in Qigu Lagoon changes between the Japanese gizzard shad, red-mouthed tigerfish and rabbitfish from season to season. Qigu Lagoon is a great place for fish larvae. 17 families, 17 genera and 19 species have been recorded. Chanidae and Engraulidae are the dominant species in spring and summer. Numerous giant mud crabs, flower crabs and mangrove swimming crabs are common in this area.
The Qigu Estuary Mangrove Lookout is about two stories high. It is surrounded by fish farms and wetlands, and they are all below sea level. The mangrove mass in this area is the best nocturnal roosting site for many Ardeidae birds. Skewers of great egrets, little egrets and black-crowned night herons fly by in the dawn and dusk. The sight is very beautiful. At least five Ardeidae species breed here. The sight of orange sunset, green trees and egrets is one of the most beautiful views at Taijiang.