Those sliced from smaller species on the croaker family tree were commonly used in cooking, while the much larger specimens that came from the giant yellow croakers cost many times more and were consumed typically for specific medical benefits. Nonetheless, until a few decades ago, croaker populations held steady. The 40 or so boats that hunted them when they swarmed the mouths of the Yangtze and other southern Chinese rivers to spawn usually landed a few dozen fish a day.
But the use of mechanical engines, which took off in the s, changed things dramatically. Suddenly boats were returning with hundreds—sometimes even a thousand—giant yellow croakers a day, according to research by Yvonne Sadovy, an expert on the bladder trade at the University of Hong Kong. This over fishing decimated the croaker population. In the late s, boats hauled up 50, tonnes of giant yellow croaker a year; three decades later, it was as little as 10 tonnes.
Another effect was to sharply reduce the average size of the croakers caught. As a result, the price of large bladders soared. In real terms, that means the price multiplied nearly fivefold in a mere three decades. What drove the demand was that in times of strife, Chinese households have been known to stockpile the more valuable bladders as speculative investments , on some occasions even trading them as currency.
The Chinese government reacted with a stimulus package that sent easy money sloshing around the economy—adding up to Though the trade in bladders is illegal, Hong Kong customs authorities are very lax about screening for them, traders told Greenpeace. Since the late s, catching the endangered totoaba has technically been illegal. When the crisis hit, tourism—a leading industry in the upper Gulf of Mexico and the major alternative to shrimping and fishing—foundered.
Totoaba bladders, however, offered a quick profit. The swimbladder is a crucial organ in successful osmoregulation, so supporting it gives your fish the best chance of recovery. Learn why tonic salts help fish in a freshwater aquarium. Fish affected by swimbladder issues struggle to stay buoyant. They can get exhausted trying to stay upright, or trying to feed.
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Recommend AccessScience to your librarian. There is a commonly kept fish species where swimbladder disorders are unfortunately common; goldfish.
The root cause of swimbladder issues within fancy goldfish is down to artificial selection. Artificial selection is the human process of choosing animal breeding stock to promote a particular trait within the offspring. With fancy goldfish, their internal organs that evolved within wild goldfish are now contained within a body that is shorter and more egg shaped than the original body shape.
When presented with a wobbly goldfish, it can be very difficult to determine what the best course of action is. We can sometimes fix this. Temperature Shock - Sudden changes in temperature can affect the swim bladder. This is because both air and water have different densities at different temperatures.
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