The Mudwallow Oyster Burrow is an underground biological structure stretching 900 meters from the small fishing village of Mudwallow to the WasteWorks Mudwallow filtering station. It was designed by M.K. Corral under contract for Shellard's Seafood to save on pearl harvesting costs, by centralizing the operation and slowly feeding the output back into the market under the pretense of natural generation. The burrow was eventually discovered and partially destroyed in a botched sabotage by local pearl fisherman.
As rising pollution levels devastated the local oyster population, both local and corporate pearl harvesting operations were forced to make expensive trips to deeper and cleaner water. Shellard's Seafood, having previous worked with M.K. Corral to develop fish breeding channels, contacted the facility to create an efficient and self-sustaining method of generating pearls. The resulting organism was capable of consuming calcium carbonate and converting it into pearls that were indistinguishable from their natural counterparts.
The site for the oyster burrow was chosen due to Mudwallow's geology and climate, being situated on a large limestone outcrop on the temperate western side of Ivykeep. The organism was initially placed in a natural cave underneath Shellard's existing Mudwallow offices, and guided into the limestone vein using rebar. The burrow grew at a rate of approximately 175cm/day and produced around 800 pearls/week, lower than the company's usual output but with almost no overhead costs.
The burrow was kept secret throughout its operation, and Shellard's kept up pretenses of regular operation by deploying cheaper, one-man vessels on “harvesting” trips. Pearls were collected from the burrow and fed back into the market slowly to avoid outpacing demand and driving down prices.
After 17 months of operation, workers were alerted that the burrow had breached the underground holding tank of Wastework's Mudwallow filtering station, which contained over fifty thousand cubic metres of liquid waste (primarily sewage). The waste poured down the tunnel, reaching the Shellard's offices and overflowing into the streets of Mudwallow. After the last of the waste had flown through, the burrow began to show signs of sickness and dropped the majority of its pearls onto the tunnel floor.
Over the next few hours the existence of the burrow was revealed through various reports and investigative journalists, sparking outrage from local pearl farmers. Despite efforts from Shellard's to suppress the riot, locals stormed the filtration system in an attempt to destroy the burrow with small explosives. Their actions, however, ignited the gasses left behind from the waste flow and caused a shockwave which blasted an estimated 80,000 loose pearls down the tunnel and out into the streets of Mudwallow.
The cleanup effort was monumental, and was obstructed by the volume of pearls in the streets which enticed locals and visitors to scavenge. Thousands of these pearls began flooding markets around the Kingdom, and prices plummeted to a fraction of their pre-incident value. Both Shellard's and local farmers were forced to abandon the industry.
The burrow, although now dead and devoid of pearls, remains intact. Some locals use it for emergency transportation but the foul odor prevents any major developments.
It is unknown why the burrow was allowed to come so close to the filtering station. Some speculate that workers were trying to “thread the needle” between the station and a nearby granite vein in an attempt to reach and destroy some kind of Utopia Project communication center, but there is little evidence supporting this.
Later testing revealed traces of unidentifiable tissue in Shellard's “Everything in the Sea” Chowder. Shellard's denies that they used meat from the burrow in the product, as it was “not from the sea”.