Scientists from the University of East Anglia have found that a quarter of the UK's rare species live in the Fens.
Thirteen creatures, including otters, white-clawed crayfish and Desmoulin's Whorl Snail are at risk on a global scale.
Water buffalo have been brought in to graze the land and create the right conditions for the smaller species.
Today there is just 1% of the Fenland that originally existed here. Two thousand of the UK's rare species can be found here but in the past 25 years more than 500 of those have not been spotted.
This survey will help future schemes to stop more species from disappearing. In this ecological audit - the bottom line is survival.