The wedgefish is listed as critically endangered on the International Union for Conservation of Nature and Natural Resources (IUCN) Red List, but data on this fish still scarce in Taiwan. To understand the ecology and habitat utilization of the migration and movement of wedgefish, the Fisheries Research Institute of the Ministry of Agriculture released one Rhynchobatus australiae and one Aetobatus flagellum through satellite trackers attached in the waters off Penghu and Yunlin. This was the first successful labeling of the release of wedgefish in Taiwan, and the data obtained in the future will be used as a reference for resource management strategies.
According to the Fisheries Research Institute, some fishermen refer to the wedgefish as a shovelnose shark, but it actually belongs to the family Rhinidae in the order Characiformes (note: the previous family has been merged into the family Rhinidae). The wedgefish has a large body size, and its fins (dorsal and caudal) are expensive. Due to fishing pressure, their numbers have declined. In addition, their habitat environment overlaps greatly with human activities, making it easy for the population to deteriorate due to habitat destruction and loss. Therefore, the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) included all species of wedgefish in the list of trade controls in 2019.
The Fisheries Research Institute has further explained that Taiwan's wedgefish is mainly found in the waters of Taichung, Yunlin, Chiayi, and Penghu. In the past, due to the large number of catches, wedgefish were not only consumed in Taiwan but also exported or transported live to aquariums for display. However, detailed statistical data are not readily available. To master the resource information of Taiwan's wedgefish, the Fisheries Research Institute has been commissioned by the Ocean Conservation Administration to conduct relevant research since 2023. In addition to strengthening the investigation of its catch size and reproductive season, in June of this year, one Rhynchobatus australiae and one Aetobatus flagellum were successfully identified by trackers and released in the waters off Penghu and Yunlin. The Institute hopes to further understand the migration ecology and habitat utilization of endangered cartilaginous fish through the transmission and analysis of satellite data, which can serve as a reference for formulating management strategies and contribute to the conservation of endangered cartilaginous fish.
Photo 1. Rhynchobatus australiae caught in the waters of Penghu
Photo 2. After the Completion of Satellite Identification, Rhynchobatus Australiae Was Released in the Waters off Penghu
Photo 3. Aetobatus flagellum released in the waters off Yunlin