The field was used as a hunting ground by Osaarian pirates, who would attack and raid any ship which was disabled by the anomalies. In 2153, they attacked Enterprise in this manner, stealing a number of resources and supplies from the Starfleet vessel. The next year, subsequent to the destruction of the entire sphere network, the field was returned to normal space, along with all of the spatial distortions in the Expanse. (ENT: "The Xindi", "Anomaly", "Zero Hour")