History of Figgs Marsh

Having been born in Tooting Junction and schooled at Gorringe Park Middle School, I have many memories of Mitcham. However, until recently I was unaware that my ancestors lived on Figgs Marsh back in the 1840s, something I found out via the 1841 census. Does any one have any knowledge about what would have been there around this time and why a large group of people would have been living communally there, as many other people were listed on this cenus as also living on Figgs Marsh. I am aware that the area has long had a prominent travelling community and wondered if this could hold any clues. If any one has any information that they feel could shed some light on this, it would be much appreciated. As I child I would often walk across the Marsh, stopping to play on the swings on my way to school and on the way back, completely unaware that my ancestors had lived there over a hundred years before! By the way, I remember my father telling me that a live lobster was found in the Three Kings pond many years ago- does any one know if this is true or whether it is an urban legend?