Aphrodisiacs are Bad for Sustainable Fisheries, by Don Orth

Why are some fish and some fish products more valuable than others?  While the news media focuses on trade bans in shark fins, and seahorses, the swim bladder (or fish maw) is also a prized fish part.  Selling fish maw may initially appear to be a win for the fishers.  However, when fish maw is believed to possess mystical qualities, the swim bladder becomes the target of a global trade network. 

Swim bladder of the Rudd Scardinius erythrophthalmus. Photo by Uwe Gille.  CC-BY-SA-3.0. Source. 

Swim bladders (also called a gas bladder) are flexible-walled, gas-filled sacs that control fish buoyancy and may aid in hearing.  Swim bladders are only present in bony fishes and are rarely saved in most fisheries. Fish swim bladders are high in collagen and can be turned into glues. Nutritionists maintain that collagen can reduce joint pain and treat skin ailments. Sturgeon swim bladders were turned isinglass for clarification of beer before other alternatives emerged.  In some Asian cultures the swim bladder, or maw, of fishes is considered a delicacy, and dried fish maw may sell from between $20,000 and $80,000 per kilogram.  Why is the price so high?  Does it have special medicinal or aphrodisiac qualities?   Fish maw is eaten to strengthen one’s qi, or internal energy.  However, there is no evidence that fish maw is an aphrodisiac. 

Display of fish maw at Singapore festival. Photo by Too Yut Shing,  Flickr

It’s difficult to study trade in fish swim bladders because of the global nature of trade and lack of reporting. The fish species harvested for the maw product is also challenging to identify. Since 2015, the fish trading in Hong Kong introduced a new commodity code, called “maw.”   Between 2015 and 2018, 3,144–3,882 tonnes of dried fish maw was imported annually to Hong Kong (Sadovy de Mitcheson et al. 2019).  These dried imports had a declared value of $264–394 million US dollars.  

Largest fresh specimen of Chinese Bahaba, caught on 30 December 1993, outside Castle Peak Bay, western Hong Kong, as incidental trawler by‐catch (Sadovy and Cheung 2003). 

Fish maw is used more for its unique texture and ability to soak up other flavors. It is almost tasteless in itself.  Consequently, fish maw is used in many soup recipes and often substitutes for shark fins. As a delicacy, demand for fish maw means that many fish stocks around the world may be at risk to overfishing in order to meet this demand. Depending on the fish, it may take 25-35 pounds of fish to yield a pound of swim bladder.  Therefore, the most prized fish maw often comes from large fish, many of which are croakers (Sciaenidae). The Chinese Bahaba Bahaba taipingensis is a critically endangered species due to unregulated fishing and harvest of immature individuals (Sadovy and Cheung 2003).  

A porpoise, vaquita (bottom) captured as bycatch along with a totoaba in Sonora, Mexico. Image by NOAA.

Among the imports to Hong Kong, most fish maw were large croakers (Sciaenidae), Nile Perch Lates niloticus, pufferfish (Tetraodontidae), catfishes (Siluriformes), and pike conger (Muraenesocidae). In many of these fisheries, the harvest of fish maw is unregulated.  Nile Perch Lates niloticus in Lake Victoria were harvested since first introduced in the 1950s (Ogutu-Ohwayo 1990) and locals ate fried maw until the lucrative Chinese market emerged.  In 2017, Uganda, Kenya, and Tanzania earned $86 million from trade in fish maw from Nile Perch.  Declines of fish harvested for their swimbladders have occurred in French Guyana and the Gulf of Mexico.  Without regulations, foreign fleets off Guyana throw back the fish and take only the profitable bladders. The Totoaba (Totoaba macdonaldi), a large marine fish that lives only in the Gulf of California, Mexico, is one of the most highly prized fish maws on the market. Like the Chinese Bahaba, the Totoaba can attain 2 meters and exceed 100 kg.  Consequently, Totoaba is critically endangered because of the high prices. Fishing for Totoaba has been banned since 1975 but illegal fishing continues.  The Totoaba fishery threatens a small porpoise, the vaquita Phocoena sinus, with extinction as it is captured as bycatch in gillnets (Bessesen 2018; Martinez and Martinez 2018).  

Bowl of fish maw soup.  from Soupbelly.com

High-valued fish may provide a lucrative revenue stream.  Unfortunately, the rarity of certain fish such as the Chinese Bahaba, makes its swim bladder even more valuable. The solution may lie in raising awareness of the status of rare fishes, and the illegal and unregulated fishing to produce fish maw.  Should there be a ban on trade in fish maw? That's likely overkill because of lower valued fish maw products.  The maw of the most highly valued species is valued at over $1,000 (US) per kg, and often much higher (Sadovy de Mitcheson et al. 2019). Bans do not eliminate fishing when the price for the produce is so high to produce a “gold rush” mentality.  The fisheries for the Chinese Bahaba and the Totoaba are easily overfished because the combination of high value of individual fish, restricted range, and spawning aggregations make fishing more of a gold rush than a sustainable enterprise.   

References

Bessesen, B. 2018.  Vaquita: Science, politics, and crime in the Sea of Cortez.  Island Press, Washington, D.C.  320 pp.

Martinez, I.A., and E.R. Martinez. 2018. Trafficking in Totoaba maw.  Pages 149-170 in I. Arroyo-Quiroz, and T. Wyatt, editors. Green Crime in Mexico. Palgrave Studies in Green Criminology. Palgrave Macmillan, Cham

Ogutu-Ohwayo, R. 1990. The decline of the native fishes of lakes Victoria and Kyoga (East Africa) and the impact of introduced species, especially the Nile perch, Lates niloticus, and the Nile tilapia, Oreochromis niloticus. Environmental Biology of Fishes 27:81-96.

Sadovy, Y., and W. L. Cheung. 2003.  Near extinction of a highly fecund fish: the one that nearly got away.   Fish and Fisheries 4:86-99.

Sadovy de Mitcheson, Y., A.W. To, N.W Wong, H.Y. Kwan, and W. S. Bud. 2019. Emerging from the murk: threats, challenges and opportunities for the global swim bladder trade. Reviews in Fish Biology and Fisheries   29: 809-835. https://doi.org/10.1007/s11160-019-09585-9

Fish Bladders Worth More Than Cocaine, by Jordan Wheatley

In Mexico, a man was stopped at a checkpoint. Police discovered in this man’s tires that there were a bunch of black, little plastic bags rolled up. According to Mexican police, they believed this was just a normal drug bust of cocaine, marijuana, heroin, and other illegal substances (Lah, 2016). However, what was within the black bags was something very fishy… actual fish! Well fish swim bladders to be exact. There were 121 fish swim bladders that came out of these plastic bags! This kind of product retails on the Hong Kong black market for around $750,000. A separate bust of fish bladders contained 600 bladders that the Mexican police had stopped from crossing into Asian countries (Lah, 2016). 

Dried gas bladder of the Totoaba.  Photo Greenpeace Asia.

These bladders are all coming from mature totoaba Totoaba macdonaldi that were cut up and left to die. A fish uses its swim bladder in order to control its buoyancy in the water by inflating and deflating the bladder. According to certain Chinese traditions, consuming the dried swim bladders from totoaba will make you beautiful. These bladders are sold in fish markets all across China along with other preserved fish product that claim to have curable powers. The tradition that the Chinese hold on to is that fish bladders contain collagen and therefore when eaten will give you more youthful looking skin. But what makes the totoaba swim bladder different? According to the Chinese, it’s because the totoaba is a rarity and is strongly distinguished by the two tentacles on both sides of the swim bladder and it’s only present in the Gulf of California. The totoaba once supported an important commercial fishing industry (2,260 tons of Totoaba fillets were exported to the United States in 1942).  Yields fluctuated based on climate and Colorado River inflows (Lercari and Chávez 2007).  However, illegal fishing now threatens its existence.

Fresh totoaba bladders found hidden under a car’s floormats by Mexican and US border agents in 2013. Photo: Department of Justice

One of its neighbors would include the rarest marine mammal in the world, the endangered vaquita Phocoena sinus. This kind of elusive trade sadly threatens to wipe out both species. This creates a problem because when fishermen are catching totoaba they use large nets, called gill nets. Because the vaquita and totoaba are similar in size and in the same area it makes them more susceptible to be caught in the gill nets accidentally. Causing the population of both threatened species to decrease even more.

Approximate range of the Totoaba.  NOAA Fisheries

This is an issue for the ecosystem because the totoaba are critically endangered (Findley, 2010). In the Sea of Cortex in Mexico, these fish count as one of the top predators. Sardines, anchovies, and crustaceans count as the majority of their diet (Juarez et al., 2016). Considering this species’ place in this ecosystem it is essential to maintain the population here. If the population is not maintained then the area’s food chain will change. If the totoaba population declines than this will cause their prey to have a mass increase and result in primary producers to decrease. Overall, this results in a decline for all other organism that rely on primary producers.

Totoaba caught from coastal waters off San Felipe, Baja California, ca. 1954. Weight ca. 91 kg (200 pounds). Photo courtesy of Tony Reyes, San Felipe

Currently, the fines and arrests made for the smuggling of totoaba animal products have been extremely light (Joyce, 2016). This is unfortunately not a big deterrent for smugglers compared to the large sum of money they will receive from the job. The totoaba swim bladders bring smugglers the same amount of money as cocaine would! Therefore to the smugglers, the cost outweighs the consequences at this moment. This is the reason for swim bladders becoming the “new cocaine” because of their high demand. And to take into consideration that the annual funding for the US environmental law enforcers is around $76,000 for the Department of fish and wildlife and $6.5 million for the US Coast Guard (USFW, 2005). Whereas, the Drug Enforcement Administration receives around $3 billion annually (DEA, 2000). This is interesting because currently the demand for illegal animal products is just as high as the demand for illegal drugs.

Fish caught from a kayak within coastal waters of the northern Sea of Cortez off Baja California, April 2018. Length: ca. 90 cm (35 inches).      photo courtesy of Ben Cantrell, San Diego, CA.

On the other hand the Mexican government is making an effort to protect this species. They have turned the popular spawning areas for totoaba into marine protected areas. A marine protected area is an area in which animals are given a place to take refuge and human activity is highly limited. However, this 400 miles of coastline is under surveillance only twice a day by the Mexican military. This area is also the only habitat under surveillance out of the 5,000 square miles that the totoaba use to nurse and spawn. This is allowing for the rest of the area to be vulnerable for any poachers that can get their hands on the totoaba swim bladders. Altogether, there should be more assistance on the enforcement of this issue.

           

Currently, there have been efforts to solve this issue as well. In the years between 2007 and 2010, two small-scale companies started a trial involving totoaba farming (Juarez et al., 2016). The goals of this trial were to grow juvenile totoaba in captivity and then release them as stock into their natural habitat. This trial was moderately successful at first due to limited temperature control that reduced spawning capabilities. However, this provided insight and influence for other organizations to breed the totoaba eventually turning it into a very successful aquaculture program. Unfortunately, this program collapsed due to habitat degradation and overfishing of the stock. If the totoaba population is to be restored, then aquaculture is currently the best option. However, this is dependent off of the regulation of overexploitation and enforcement to maintain the population. Without this kind of regulation then the introduced stock will just decline and all efforts will go to waste. Therefore, enforcement similar to the United States Game and Inland Conservation Officers will be useful to regulate how many fish are being taken from the population. In order to apply this type of system then fisherman, stockholders, governments, private corporations, and environment organizations will need to come together in order to solve this problem for the common good. (Juarez et al., 2016)

References

DEA Staffing and Budget. 2000 [accessed 2019 Apr 8]. https://www.dea.gov/staffing-and-budget

Findley, L. 2010. Totoaba macdonaldi. The IUCN Red List of Threatened Species 2010: e.T22003A9346099. http://dx.doi.org/10.2305/IUCN.UK.2010-3.RLTS.T22003A9346099.en.

Joyce C. 2016. Chinese Taste For Fish Bladder Threatens Rare Porpoise In Mexico. NPR. Accessed 2019 Apr 8 https://www.npr.org/sections/goatsandsoda/2016/02/09/466185043/chinese-taste-for-fish-bladder-threatens-tiny-porpoise-in-mexico

Juarez LM, Konietzko PA, Schwarz MH. 2016. Totoaba Aquaculture and Conservation: Hope for an Endangered Fish from Mexico’s Sea of Cortez. 2016 Dec 15 [accessed 2019 May 6]. https://www.was.org/articles/Totoaba-Aquaculture-and-Conservation-From-sea-of-cortez.aspx#.XNBg3etKjOR

Lah K. 2016. 'Aquatic cocaine': Fish bladders are latest Mexican smuggling commodity. CNN. Accessed 2019 Apr 8 https://www.cnn.com/2016/05/23/health/aquatic-cocaine-totoaba-bass-smuggling/index.html

Lercari, D., and E.A. Chávez. 2007.  Possible causes related to historic stock depletion of the totoaba, Totoaba macdonaldi (Perciformes: Sciaenidae), endemic to the Gulf of California. Fisheries Research 86(203):136-142.

Rojas-Bracho, L. & Taylor, B.L. 2017. Phocoena sinus. The IUCN Red List of Threatened Species2017: e.T17028A50370296. http://dx.doi.org/10.2305/IUCN.UK.2017-2.RLTS.T17028A50370296.en.

U.S. Fish and Wildlife Service. 2005. Accessed 2019 Apr 8 https://www.fws.gov/budget/