We're sorry to hear about the male parent. Unfortunately, the rest of the family is going to be in jeopardy if you do not get them out of the stagnant water. They can be poisoned or become extremely ill from the dirty water. Please contact Wendy Hermon at Swan Lifeline in Eton. She may be able to help relocate the family to a healthier area. Should the family, especially the mom gets sick, there is also the chance, especially the cygnets that they can be attacked by the fox and other predators. The Regal Swan