Paravars; it is uncertain as to what period this refers or the cause of the poverty. Xavier had recorded that the oyster beds seemed to have an uneven cyclical pattern, with a few good years of production alternating with a rather longer period of poor production. Similarly, around 1490 Ahmad ibn Mājid wrote that the fisheries "flourish in some years, but appear dead in others." One contemporary explanation for these changes was that the beds became covered by the shifting sea sands. A study of the period 1666–1916 showed that while the good harvests did tend to alternate between the Indian and the Sri Lankan sides of the Gulf, the latter side was more than twice as productive. Control of the fisheries passed from the Portuguese to the Dutch from 1658, along with sovereignty over the Paravars. The new rulers, who were Protestant, tried unsuccessfully to convert the Paravars to their own faith. One example of this attempt was the banning of the feast of Our Lady of Snows as a consequence of the Dutch taking over all the Catholic churches, many of which were turned into warehouses. This event had originated when a wood statuette of the Virgin Mary was moved by the Portuguese to the church of Our Lady of Mercy at Tuticorin in 1582, its installation being celebrated with a nine-day feast which was subsequently repeated annually and much enjoyed by the Paravars. The feast halted with the Dutch takeover but was reinstated from 1709, and three years later permission was granted for the building of a new church. It was the right of the jati thalavan always to make the first tug of the rope which was attached to a chariot containing the statuette and which marked the start of the festival. The veneration of the statuette has been called a "cult" and continues into modern times, although few outside the caste have such regard for it. During the period of Catholic repression the Dutch East India Company also expelled all Catholic priests and outlawed Catholic baptisms and other rituals. Indeed, there are no surviving records to suggest that there was any evangelism at all, although they did build Tuticorin's first Protestant church in 1750. During their period of control the Dutch also established a cloth factory in Tuticorin and this was a much appreciated venture — at some point the Paravars had also become traders