Tuna mania
Tuna mania is the name given to a social and economic phenomenon that occurred in Kur'zhet and Valle Crucis and, to a lesser extent, other western Teudallic countries such as Azmir, Berique and Cadenza, in the mid-sixteenth century. It was an unprecedented event that saw an exponential increase in demand for tuna, a large oceanic fish, in the affected countries. Following a slow reintroduction of the fish to Kur'zheti markets in the late 1540s, prices suddenly rose dramatically in 1553, but demand did not drop proportionately, despite the difficulty in bringing catches north from the remote island of Valle Crucis. Tuna mania is sometimes considered the first economic bubble known from Astyria, as it saw futures being sold in tuna, speculative financing of fishing fleets and widespread and untenable inflation in the prices of tuna before the market abruptly collapsed in 1558.
Historical background
Tuna are large saltwater fish. The most common species found off the western Teudallic coast is the Jajexan tuna (Thunnus tenedoi), which grows to a maximum length of c. 2 metres (6.6 ft) and can weigh up to 190 kilograms (420 lb). Because of their size, weight and agility, they are challenging to catch in the open ocean. This, combined with the quality of their meat, means that they have always commanded a premium in fish markets. Several medieval Ethlorek authors spoke highly of tuna dishes, and a handful of poems in Kur'zhet's rich maritime literature describe the tuna as a particularly elegant and admired fish. A stone carving on the thirteenth-century Cadenzan cathedral in Laeryt that depicts Jesus and His disciples as fishermen, a motif commonly associated with the Siresian Order, is thought specifically to show tuna as the fish being caught.
Access to tuna in this area greatly increased from the late twelfth century. In 1191, the Azmiri volcano Kaië Ryio'qi experienced a dramatic eruption that is thought to have introduced tremendous quantities of minerals and nutrients into the coastal waters, including through undersea geothermal vents. Environmental historians attribute to this a substantial algal bloom that led to an explosion of plankton populations and knock-on multiplication up along the oceanic food chain. As west Azmir's rivers continued to carry ash and volcanic sediment to the sea in the aftermath of the eruption, this unusually rich environment was sustained for over a century. Tuna moved in-shore in large numbers, and coastal communities were able to catch them in large numbers in fish traps. This caused a significant improvement in these economies, enriching their eastward trade in particular and evidently leading to a surge in patronage of Catholic churches, Thaerine temples and other institutions. It is thought that this bloom was, ultimately, a contributing factor behind the Azmiri Crusade.
Oceanic temperatures dropped marginally c. 1400 in the Sea of Jajich during the Little Ice Age. At the same time, the volume of nutrients entering the sea from riverine deposition tapered off. Contemporary commentators noted the decline in tuna catches, and by c. 1450, where once large nets had been full of mature tuna, many coastal traps were abandoned and tuna were only found far out at sea. They were no longer a commercially viable catch in this region.