1. New Use of FishBase Data: Estimating the intrinsic rate (rmax) of population increase
Rainer Froese GEOMAR
14th FishBase Symposium
Amphitheatre Rouelle, MNHN
9 September 2016, Paris, France

2. Question
If you were granted the wish to know one number for every species on Earth, what number would you pick?

3. Answer
For every population, there is one number that summarizes maximum size, longevity, maturity, mortality, somatic growth, and reproductive success: rmax The maximum intrinsic rate of population increase

4. Thomas Robert Malthus (1766 – 1834, English Economist)

5. World Population Growth
"The power of population is indefinitely greater than the power in the earth to produce subsistence for man"

6. Pierre François Verhulst (1804 – 1849, Belgian Mathematician)
(1844)

7. Logistic Curve Properties
BioDivPopGrowthMSY.xls

8. Importance to Conservation
How fast populations can recover from a depleted state is determined by rmax Doubling time = log(2) / rmax ̴ 0.7 / rmax rmax = 0.7 → 1 year rmax = 0.07 → 10 years

9. Milner Baily Schaefer (1912 – 1970, US Fisheries Scientist)

10. The Schaefer Model
BioDivPopGrowthMSY.xls

11. Life History Correlates of rmax
rmax = 2 Fmsy (Schaefer 1954) rmax ̴ 2 M because M ̴ Fmsy (Gulland 1971) rmax ̴ 3 k because k ̴ 2/3 M (Jensen 1996) rmax ̴ 9/tmax because tmax ̴ 3/k (Taylor 1958) rmax ̴ 3.3/tgen because tgen ̴ 1/k (Roff 1984) rmax = f(Fecundity < 1000) (Musick 1999) These relations were used to predict rmax in FishBase for currently close to 1000 species:

13. Resilience

14. rmax vs Size

15. Differences by Class

16. Climate

17. Freshwater vs Marine

18. Environment

19. Migratory Behavior

20. Phylogenetic Uniqueness

21. Next Steps Include published estimates of rmax in FishBase
Use a Bayesian hierarchical approach to estimate rmax for all species
[ Beware what you wish for…]

22. Thank You