Thursday, November 21, 2019

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

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.   


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.

Tuesday, November 5, 2019

In Search of Monster Fish: Angling for a More Sustainable Planet, Book Review by Don Orth

Mark Spitzer’s latest book, In Search for Monster Fish: Angling for a More Sustainable Planet, will appeal to all types of anglers and adventurers. Mark Spitzer is an Associate Professor of Creative Writing at the University of Central Arkansas and author of over twenty-five books.  His previous forays into fish writing include three non-fiction books: Season of the Gar: Adventures in Pursuit of America’s Most Misunderstood Fish (2010, Return of the Gar (2015), and Beautifully Grotesque Fish of the American West (2017).  He has also written fishy fiction, e.g., Garapaima: A Monster Fish Novel (2015).     

In Search of Monster Fish is a series of stories in which Spitzer seeks out a new monster fish.   Although he doesn’t formally define “monster” fish, it is apparent that size matters and big teeth add to the mystique. The term was popularized by National Geographic’s Monster Fish show.  But there are so many monster-fish stories to tell, we cannot get enough. The author’s purpose goes beyond showing off his fishing skills.  It’s more about the search. 

Book cover of In Search of Monster Fish shows Mark Spitzer with a Doitsu variety koi carp. 
Fishing is often a never-ending series of quests. Many serious observers have identified 5 stages of an angler’s life, stated simply as Any Fish, Many Fish, Big Fish, No Fish, and finally Give Back Fish (McKenna 2013).  Each monster fish was something new for Spitzer to pursue.  Each quest required new skills and a new place. Every story contains some daily conversation with himself about why he's here. He asks "What was I put here to do?This is a deep and difficult philosophical question to pose in a book entitled In Search of Monster Fish. It is those daily conversations that make this book most interesting.  In the first chapter, “Demythologizing Demonologies,” we join Spitzer, guide Wilson, and Lea the fun-loving poetry professor, in the Amazon in pursuit of monster fish myths. Their first fish, which the guide called dormelinas, was captured by swinging a machete. He begins the conversation about the monster fish mystique as they learn to catch and eat local fish (piranha fritta) from their guide. 
In “Catfishalonia,” Spitzer seeks to catch a Wels Catfish, Siluro or Silurus glanis.  This is the biggest freshwater catfish which can exceed 200 pounds and 7 feet. It is an opportunistic catfish and in the Ebro River it’s referred to as "The Ebro Monster.”  Like other catfish, it feeds at night on fish, ducks, voles, and the misplaced American red crayfish (Procambarus clarkii).   In 1974, a German fisheries biologist named Roland Lorkowsky introduced young Wels Catfish to the Ebro River to create a recreational fishery. The Ebro is no pristine river; rather, it’s a working river with hydroelectric dams, nuclear plants, chemical plants, orchards, and animal agriculture. By the late 1980s, anglers were boasting of catches of catfish over 90 pounds, which led to guiding industry for tourist anglers. While I was reading this book, a British angler caught an 8-foot albino catfish that weighed 194 pounds. Spitzer does not exaggerate about monster fish. Watch Spitzer vs Wels Catfish to see the outcome.
In “Cuda Chaos in the Dominican Republic,” Spitzer and his now fiancĂ©e are beaten by ocean waves in search of barracuda, in particular small ones because the largest Barracuda have toxic levels of the ciguatoxin. Nothing prepares one for rough waters, but Lea and Mark eventually catch and eat Barracuda in a Cuda creole. In “Sportfishing Gar,” Spitzer explores his local fishing water, Lake Conway, which contains three species of gar. Spitzer is experienced catching them with jug lines and trot lines, but this adventure represents his very first efforts at catching gar with a rope lure.  See Doug Jeffries YouTube video for instruction on making a rope lure.  After initial success, his next trial is to catch a gar on a fly.   But this quest becomes a lesson in learning to fly cast like an experienced fly fisher—not a goal for amateur.

Mark Spitzer with Alligator Gar.  (c) Mark Spitzer
After a honeymoon in Borneo, he is jet-lagged while “Monster-fishing shark off Montauk,” the eastern end of the Long Island peninsula in New York.  He solicits the help of Captain John Krol aboard the Let’s Go Fishin. Captain John has been fishing these waters since the 1980s.  Montauk is the site of an annual shark tournament with big money prizes and donation of shark meat to food pantries. Spitzer opens a brand new bucket of chum, and raises questions about shark hunting. Captain Krol tells him “it used to be all about tuna out here, but when the tuna thinned due to the mushrooming markets, something else had to take its place.  Shark then became the thing.” According to the experienced Krol, everything is down compared to the past.  Before tuna were completed fished out, “there was only shark hunter in these waters...Frank Mundus. After trying to kill everything in the ocean, he became a conservationist…then tried to save everything in it.”   True, “Monster Man” Mundus is well-known in the region and was the inspiration for the character Quint in the book and movie, Jaws. 
After a Great White Shark terrorized a New England town in the movie, Jaws the interest in shark fishing grew and shark tournaments incentivized shark harvest.  Shark are extremely vulnerable to overfishing due to low reproductive output, high extinction risk, and intrinsic vulnerabilities to overexploitation.  Recreational fishing for sharks is a global management concern (Babcock 2009; Shiffman 2014; Gallagher et al. 2017).  Frank Mundus was responsible for calling shark fishing “monster fishing,” which gained notoriety when he harpoon-captured a massive white shark off Montauk that he estimated at ~2000 kg in 1964 (4500 pounds) (Mundus and Wisner 1971). It’s true that Mundus became a shark hunter turned conservationist.  He was promoted circle hooks, initiated a shark tagging program, and advocated for catch and release. Today there is a one shark per day limit with 54-inch minimum regulation. 
Shark hunting is very controversial, and Spitzer gets his facts straight.  Worm et al. (2013) estimated that the total number of sharks killed by fisheries each year is between 63 and 273 million, with an average of approximately 100 million. The problem is overfishing and as Spitzer writes “monster fish have a lot to teach us, but to learn from them we need to keep them around.” While chumming for sharks, he observes large fishing trawlers and reflects on his fishing quests for monster fish.   Spitzer writes “…I was heading in the right direction, but if this monster-fish thing is really more than just an excuse for me to go fishing, then I need to look even harder. Way harder!” 
In Monster carp in France, Spitzer tries a week of extreme carp angling.  Carp know no borders and the Itkus fishing lake is designed to make carp anglers respect their borders.  Each section of the fishing lake is called a ‘swim’ and anglers reserve their swims. If you get skunked in your assigned swim, no wandering to other areas of the lake is permitted.  Spitzer must admit his ignorance in order to catch a monster carp. Specialized carp rigs include hair rigs, boilies, long carp rods, and pop-up rod alarms. These are extreme carp anglers who drive and survive during a long week of carp angling. Fish are caught, photographed, and released to bite againbut only after the extreme angler applies first-aid cream to damaged carp lips.  Anything that helps reduce the ingress of bacteria into open wounds is likely to benefit the carp.  However, this technique has not been transferred to North America.  Carp are a learned preference for monster fishing.  Clearly, in managed waters they can reach monster sizes, as long as one practices catch and release.  Mirror carp, a genetic mutation with scattered scales covering only part of the body, were a target here. Spitzer was skunked on some days, but did land the Doitsu variety Koi which is pictured on the book's cover. It remains a great paradox that carp are such a highly desired species in some places while reviled for its dominance and damages in lake ecosystems in other places. 
“Bananas from Tarpon” is Switzer’s quest to catch tarpon and supersize stingrays in Gambia.  With his “boss lady” Lea, his guides Farmara, Junior, and Fabu, he eats his first stingray, complete with gelatinous skin and cartilage.  Although he was thrilled to catch a “large” tarpon, it was barely large enough to qualify as an adult specimen.  His conversation gets back to his development as an angler and what he can put back. Food security in Gambia depends on catching and keeping fish.  The old saw “Game fish are too valuable to only by caught once” really doesn’t make sense here. Humans are a species that looks out for itself first. His thinking is turning as he travels to Senegal with thoughts of monster billfishes, Zane Grey, and Ernest Hemingway.  Here near the heart of the world’s richest fishing areas, the local fishers were harvesting Skipjack Tuna Katsuwonus pelamis with handlines from small boats, called pirogues.  But larger vessels and foreign trawlers are threatening the livelihoods of Senegalese artisinal fishers. Spitzer casted for small tuna and used them as bait for his pursuit of billfishes including the Blue Marlin Makaira nigricans, a species threatened by overfishing.  Before long, he switches his target to the Dorado, or Mahi Mahi Coryphaena hippurus, and he reflects again on putting back.
In the “Italian Zander” the conversation continues with twenty ways to put back more. His interest in Monster Zander peaked after a story of monster fish terrorizing swimmers in a Swiss lake. It’s very unusual for Zander Sander lucioperca to attack humans, but the strange story initiated his quest. The Zander is closely related to the Walleye Sander vitreus. In fact the world record Zander at 25.3 pounds, is only slightly larger than the world record Walleye at 22.7 pounds, from Greer’s Ferry Lake in Arkansas. With his guide, Fabrizio, he fishes Lake Como in northern Italy.  This natural lake has a fish fauna that is altered by widespread stocking of non-native fishes (Volta et al. 2018).  After catching a Zander, European chub, European Perch, Northern Pike, and a North American favoritea Largemouth Bass, he returns to the conversation before traveling to the boot heel of Italy to pursue Conger Eel.   You see there is a myth about a 130 pound Conger Eel landed off the coast of Devon. The European Conger Conger conger reaches a maximum size of 3 meters though more typical big ones are 1.5 m. I suspect this trip was more about the seafood. His guide, Antonio, had a mis-shapened finger from a Moray Eel encounter and spoke only Italian.  The longline they fished encountered several species, including some Conger, but mostly the longline caught immature fish.  While his reward was buona murena fritta, the reminder of overfishing immature fish troubled him.

The concluding chapter is “Solutions for  Disenlightenment” where Spitzer finishes his conversation about giving back.  Without giving away the ending, he examines why monster fish are so sacred to him.  What is a man without monster fish?  What are reasonable solutions?  We need scientists and discovery and more types of FishLove.  No single, simple answer exists “to sustain the terrifying beauty of this mind boggling, mind blowing, and mind altering monster fish world.” (Spitzer 2019, p. 180).  I recommend that you join Mark Spitzer on his expeditions in this fun- and monster-filled book and plan your next fishing quest.


Babcock, E.A. 2009. Recreational fishing for pelagic sharks worldwide.   Pages 193-204 in I.-M.D. Camhi, E.K. Pikitch, and E.A. Babcock, editors. Sharks of the open ocean: Biology, fisheries, and conservation.  Blackwell Publishing, Oxford.
Gallagher, A.J., N. Hammerschlag, A.J. Danylchuk, and S.J. Cooke. 2017 Shark recreational fisheries: Status, challenges, and research needs. Ambio 46(4):385-398. doi: 10.1007/s13280-016-0856-8
McKenna, M. 2013.  Five stages of a fisherman’s life.  Sun Valley Magazine   March 18, 2013.  Accessed 7 February 2019 from
Mundus, F., and W.L. Wisner.  1971. Sportfishing for sharks. Collier Books, New York.
Shiffman, D.S. 2014. More large sharks were killed by recreational anglers than commercial fishermen in the US last year. Retrieved November 3, 2019. Available:
Spitzer, M. 2019. In Search of Monster Fish: Angling for a More Sustainable Planet. University of Nebraska Press, Lincoln, Nebraska. 189 pp
Volta, P., E. Jeppesen, P. Sala, S. Galafassi, C. Foglini, C. Puzzi, and I.J. Winfield. 2018.  Fish assemblages in deep Italian subalpine lakes: history and present status with emphasis on non-native species.  Hydrobiologia 824:255-270    Worm, B., B. Davis, L. Kettemer, C. Ward-Paige, D. Chapman, M. Heithaus, S. Kessel, and S. Gruber.  2013. Global catches, exploitation rates, and rebuilding options for sharks. Marine Policy 40: 194-204.