1) This document discusses using biological traits to assess extinction risk for freshwater fish species since direct estimates of risk are lacking for most species. 2) The author developed a model to predict IUCN Red List status based on 5 traits for over 14,000 freshwater fish species. 3) The model identified species with high "latent extinction risk" - they have traits associated with risk but are not currently considered threatened. These species are priorities for further research, monitoring, and conservation assessments.

1. Latent Extinction Risk of Freshwater Fishes
A traits-based approach to inform conservation ranking schemes
Julian D. Olden
University of Washington

2. Challenge Synopsis
• Conservation biology is faced
with a growing urgency to
identify and protect species
facing the greatest risk of
extinction (Pimm and Jenkins 2005)
• This is a challenging task, in large
part, because direct estimates of
extinction risk for most species
are lacking (O’Grady et al. 2004)
• Species’ traits provide a powerful
currency of investigation that can
help guide conservation efforts

3. Extinction Risk of the World’s Fishes
484 red-listed
freshwater spp.
132 red-listed
marine spp.
* P<0.10
** P<0.05
*** P<0.01 Olden et al. (2007, Global Ecol. Biogeog.)

4. Species Profiling
Biological and ecological traits
provide a basis for species
profiling, which helps:
• identify species threatened
by imperilment and
prioritize resources toward
those with the greatest need
• inform conservation ranking
schemes by quickening the
assessment process

5. Extinction Risk for Desert Fishes
• The American Southwest harbors a
highly endemic fish fauna
• Human pressures are particularly
severe, where over 30 million
people depend on water for
human consumption, agriculture,
hydroelectricity, and recreation
• How do multiple biological traits
interact to predispose desert fishes
to rarity, local extirpation and
global risk of extinction?

6. • Large-bodied species with delayed maturity and specialized diet
exhibited higher probabilities of extirpation
Synergisms among several
traits increasing the
susceptibility of endemic fishes
to multiple stages of the
extinction, from species rarity
to local extirpation to global
extinction
Olden et al. (2008, Ecology)

7. Latent Extinction Risk
• Latent extinction risk is defined as the discrepancy between a
species’ current conservation status (i.e., level of imperilment) and
its expected status predicted by its suite of biological and ecological
traits
• Species with high latent risk represent:
– beacons for future research/monitoring
– priorities for conservation assessments
– potential contributors to future extinction debt
• Given limited resources for conducting detailed species
assessments, identifying trait-based indicators of extinction risk
could be extremely valuable for conservation ranking schemes

8. IUCN Red List # fish
species
Extinct (EX) 90
Extinct in the Wild (EW) 13
Critically Endangered (CR) 278
Adequate data
Endangered (EN) 232
Vulnerable (VU) 633
Evaluated
Least Concern (LC) 1,262
Near Threatened (NT) 58
All species
Data Deficient (DD) 428
Not Evaluated (NE) 11,523

9. IUCN Red List - Challenges
37% of evaluated species are listed as threatened
80% of species have not been evaluated
Substantial taxonomic bias in evaluated species
100%
80%
60%
40%
20%
0%
Cyprinidae Salmonidae Acipenseridae Not Evaluated
(2,752) (164) (26) Evaluated
Family (Ranked order)

10. Latent extinction risk of the World’s fishes
Objective Determining latency
Identify fish species of global
conservation concern according Predicted Risk
to latent extinction risk Low High
Approach Latent
Low
risk
Assessed Risk
• Collate data on 5 biological traits
(max. size, longevity, maturation size,
fecundity, reproductive guild) for
14,517 freshwater species High
• Develop a random forest classifier to
High
recovery
predict IUCN Red List ranking potential
according to species traits
• Identify species that possess
extinction-prone traits but are not
currently considered threatened

11. IUCN Red List Categories
Extinct (EX)
Classifier development
Extinct in the Wild (EW)
and validation
Critically Endangered (CR)
Adequate data
Endangered (EN)
Vulnerable (VU)
Evaluated
Least Concern (LC)
Near Threatened (NT)
application
All species
Classifier
Data Deficient (DD)
Not Evaluated (NE)

12. Model performance Fish species whose traits are
• 75% correct classification symptomatic of extinction risk
(Cohen’s κ=0.51, P<0.001)
Least concern: Species with
potential latent extinction risk
Least concern • Priority for monitoring and re-
evaluation
Near threatened Near threatened: Species that
are currently at-risk
Data deficient • Promote to threatened status
Data deficient
Not evaluated
• Priority for additional research
0% 20% 40% 60% 80%100%
Not evaluated
Predicted at-risk Lower concern • Priority for species evaluation

13. Percidae - Darters
Etheostoma &
Percina spp. (112)
Gobiidae
Luciogobius albus
Heptapteridae Australian lungfish
Pimelodella spp. (55) Neoceratodus forsteri

14. Proposed Revision to Red List Categories
Extinct (EX)
Extinct in the Wild (EW)
Critically Endangered (CR)
Adequate data
Endangered (EN)
Vulnerable (VU)
Evaluated
Least Concern (LC)
Near Threatened (NT)
All species
Data Deficient (DD)
Potential Threatened (PT)
Not Evaluated (NE) Not Evaluated (NE)
Lower Priority (LP)

15. Future steps …
• Trait-based approaches • Species with high extinction
provide an opportunity to latency should be afforded
identify at-risk species and high priority for evaluation via
help inform conservation single-species analysis and the
ranking schemes development of additional
specialist groups
– Salmonid SG
– Sturgeon SG
– Freshwater SG

16. Acknowledgements
Mark Kennard
Kirk Winemiller
Fabien Leprieur
Emili García-Berthou
Pablo Tedesco
Will Darwall (IUCN)
Rainer Froese (FishBase)
Funding:
NSF, NSERC, EPA, USGS, DoD