Two stable states

high algae or high aquatic plants
can be caused by P loading or the decrease in humic input

Each state has a degree of resilience

how far that state has to be pushed or perturbed to "flip" to the other state
i.e. MSS have two thresholds, one on the way up and a different one on the way down
this is good news if you're in the low state and want to stay there
it's bad news for recovery

more bad news

results in lakes shows that there may be additional perturbations required to overcome a blockage
such as a biological manipulation to destabilize the resident community
dutch lakes - killed the birds, the benthivorous fish and added zebra mussels