by Jason Baumsteiger and Peter Moyle In part I of our blog, we projected a bleak future for many freshwater fishes, especially in California.
What if it no longer exists in its natural habitat or in the wild?
In our recent paper (Baumsteiger and Moyle 2017), we attempted to tackle these questions and provide an honest, although imperfect, way to assess extinction.
This is an area between formal threatened/endangered status and global extinction, where a species is in limbo – it is partially extinct.
Categorizing “grey extinction” Mitigated extinction- This category represents the many ways that a species can become dependent on humans for its existence.
Native-range extinction – As the name implies, this is a species which no longer exists in its natural range but may exist elsewhere (say a reservoir somewhere).
Wild extinction – This category is one step further than native-range extinction.
Apparent extinction – This category is the final “holding pattern” category when we think the species is globally extinct because we cannot find it anywhere.
As a species becomes endangered, we start doing everything we can to conserve that species, one species at a time.
When we put these ideas together, we generated a decision tree to help navigate the many categories and approaches that one might take in assessing extinction (Fig.