Escalating Threat to Marine Wildlife from Trade Demand for Croaker Fish Swim Bladders

Vaquita and tototaba on a totoabera net. Photo: O. Vidal


The CSG has a long history of engaging in efforts to save the vaquita porpoise from extinction due to bycatch in gillnets targeting the totoaba croaker for its swim bladder or maw. Earlier this month, a letter was sent to the CITES Standing Committee expressing our concern about Mexico’s compliance with its “Action Plan to Prevent Fishing for and Illegal Trade in Totoaba, their Parts and/or Derivatives, to Protect the Vaquita”. Also this month, Brian Smith, Cetacean Specialist Group Asia Co-coordinator and Director of the Wildlife Conservation Society’s (WCS) Marine Wildlife Bycatch Reduction Initiative, together with co-authors from Bangladesh, published a journal article pointing out that the heightened value of croaker swim bladders is contributing to the endangerment of numerous other marine species, including globally threatened dolphins, porpoises, sharks, rays, marine turtles, and other croakers with valuable maws. One of the co-authors, Elisabeth Fahrni Mansur, is Regional Vice-Chair for the Indian Ocean of the IUCN Shark Specialist Group.

Irrawaddy dolphins are frequently bycaught in coastal gillnet fisheries in Bangladesh that also catch Black-spotted croakers with maws selling to international traders for up to several thousand USD each. Photo credit: WCS Bangladesh


Gillnet fisheries and other coastal fisheries that catch croakers with high-value maws are intensifying in several areas, driven by the enormous demand, primarily in China, for croaker maws as a luxury or status food and a profitable financial investment. This is exacerbating a conservation crisis already facing cetaceans and other marine wildlife due to fishery bycatch. An IUCN motion on monitoring and controlling trade in croaker swim bladders was approved at the 2021 IUCN World Conservation Congress. This motion called on member nations to support the establishment of trade regulations on croaker fish maws through national laws and CITES regulations.

To further investigate the link between the trade demand for croaker maws and fisheries that bycatch threatened marine wildlife, including cetaceans, an online survey will soon be circulated to the CSG and members of other relevant IUCN specialist groups. Information from this survey will enable the CSG and others to address this rapidly growing threat more effectively.


Smith, B.D., Mansur, E.F., Shamsuddoha, M. & Billah, G.M.M. (2023). Is the demand for fish swim bladders driving the extinction of globally endangered marine wildlife? Aquatic Conservation: Marine and Freshwater Ecosystems, 1–6.