I'm working with fish data from several reservoirs inserted in different watersheds. I want to do a spatial analysis with the composition of non-native species in these environments, and for that I need to decompose my space into PCNMs. I want to use the hydrologic distances from my reservoirs to build the spatial matrix, but I do not know how to handle my data from non-connected reservoirs. Because if I put distance 0 in the cell, it will consider one point on top of the other.