Increasingly in recent years, Hong Kong has demonstrated its role as a key trade hub for innumerable wildlife products, including ivory, pangolins (both the animal and their scales) and agarwood, to name just a few. Among marine wildlife products, shark fin and live reef food fish are perhaps the most salient given the prevalent media coverage on their plight. There are a few, however, that have not been given as much attention, yet still represent serious conservation issues worthy of discussion. Fish maw is one such example.
Fish maw is the dried swim bladder of some species of fish and holds a prominent place in many of Hong Kong’s dried seafood markets. Although inconspicuous and unappealing in appearance – they resemble wrinkled, half-deflated and brownish-yellow balloons – a high quality fish maw can fetch up to HKD $96,700/kg, earning it the nickname among fishers of ‘soft-gold’.
These high quality fish maws conventionally came from two specific fish species, one of which was once prevalent in Hong Kong waters. The Chinese bahaba or Giant yellow croaker (Bahaba taipingensis) is just as plain-looking on the outside as on the inside. They are naturally distributed in the waters around Hong Kong, mainland China, and Macau, but have largely disappeared from here. Price of the fish maw will depend on the fish’s size (they can grow up to 200cm in length, weighing 100kg), its sex and the season in which it was caught,.
A curious characteristic of the Chinese bahaba is its ability to generate sound, using a very strong muscle to stimulate vibrations in the swim bladder, an ability that is relatively rare among fishes. The Chinese bahaba uses these calls to attract mates and during spawning aggregation, their calls can be heard by waiting fishermen. Targeting aggregations is a particularly efficient and devastating method of fishing, wiping out entire populations in one catch. As a result, the species is now classified as commercially extinct and is categorized as “Critically Endangered” under the IUCN Red List of Threatened Species.
Though local populations have been largely extirpated, consumer demand is fed by more than one source or species, as with many other wildlife products. The totoaba (Totoaba macdonaldi) is closely related to the Chinese bahaba, although they live in different areas. The totoaba is endemic to the Gulf of California and, like the Chinese bahaba, were once abundant in local waters.
Fish maw of totoaba can also be found in the Hong Kong market, continuing to stimulate local demand. In 1996, the species also became “Critically Endangered”. Then, in 1976, the totoaba was listed on Appendix I of CITES (Convention on the International Trade in Endangered Species), meaning that all international trade in the species is prohibited.
As if the situation could not be worse, the totoaba fishery has also put a third species at risk: the vaquita (Phocoena sinus), the world’s smallest porpoise. Despite there being little demand for this species, the vaquita unfortunately also lives exclusively in the Gulf of California and its populations have been decimated simply by being caught in nets intended for totoaba. As a result, there are now only 30 vaquita left in the wild.
Scientifically, very little is known about the Chinese bahaba, totoaba, and vaquita, and they are likely to disappear altogether from our waters before more can be known. Once again, the demand for a single commodity has both directly and indirectly driven three unique species to the brink of extinction.
The problem of bycatch has long been under the radar, and comes under one of the assessment criteria for several sustainable seafood assessments,. When buying seafood, do we know how many species we might be putting at risk?
It never hurts to question the source of what we put in our mouths. As responsible consumers, we must equip ourselves with knowledge of where our food comes from and how our choices may be affecting communities and ecosystems at the source and along the supply chain to your plate.
Author: Stan Shea and Kathleen Ho
 Personal observation, 2017
 Ng Wai Chuen & Cheung, W. (2006). Bahaba taipingensis. The IUCN Red List of Threatened Species 2006: e.T61334A12463147. Retrieved from http://dx.doi.org/10.2305/IUCN.UK.2006.RLTS.T61334A12463147.en.
 Sadovy, Y. and W.L. Cheung, 2003. Near extinction of a highly fecund fish: the one that nearly got away. Fish Fish. 4:86-99.
 Findley, L. (2010). Totoaba macdonaldi. The IUCN Red List of Threatened Species 2010: e.T22003A9346099. Retreived from http://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T22003A9346099.en.
 WWF Global. (2017). Sustainable seafood guides methodology. Retreived from http://wwf.panda.org/how_you_can_help/live_green/out_shopping/seafood_guides/methodology/
 Marine Stewardship Council. (2014). MSC fisheries standards and guidance v2.0 (extracted from annexes SA, SB, SC and SD of the Fisheries certification requirements v2.0). Retrieved from https://www.msc.org/documents/scheme-documents/fisheries-certification-scheme-documents/fisheries-standard-version-2.0