1. Stochastic Transport Generates Coexistence in a Nearshore Multi-Species Fishery Heather Berkley, Satoshi Mitarai, Bruce Kendall, David Siegel, Robert Warner NSF Biocomplexity Project - Flow, Fish and Fishing

2. Multi-species Model Stochastic dispersal as a mechanism for coexistence What is impact of stochastic dispersal on interactions? What factors will influence coexistence? Diffusive Dispersal: competitive exclusion Stochastic Dispersal: can coexist

3. Packet Model Larval settlement as arrival of N packets L = domain size l = eddy size (50 km) T = Spawning time t = eddy turnover rate (14 d) eddy size ( l ) N larval packets

4. Modeling 2 Species w/ Different Spawning Times Considering 2 species with similar life histories (Life span, Fecundity, PLD, etc) Differences in when and how long they release larvae will impact where their larvae settle Packets released within 14 days will end up in the same location

5. Spawning Window Overlap Specify how many days of overlap between spawning times for both species Makes some packets perfectly correlated for both species and others independent Packets will have same settlement locations Species A Spawning Window Species B Spawning Window TIME

6. 2 2 1 1 Species A Species B Distribution of Packets ~Half of spawning windows overlap

7. 2 2 1 1 Species A Species B Distribution of Packets ~Half of spawning windows overlap ~Half of the packets settle in the same locations

8. Parameters spawning time= 30 days for both –Vary amount of overlap Fecundity of Sp.A = 0.5 Fecundity of Sp.A = 0.45 Adult Mortality = 0.09 Run time = 500 yrs; Patch size = 5 km; Domain size = 500 km; Larvae on larvae DD (total # of both sp) Averaged over 10 simulations

9. Species A Species B Adult Population Single run No overlap in spawning times Packet transport => patchy distribution Coexistence

10. Species A Species B Mean Adult Abundance

11. Species A Species B 0 days of overlap

12. Species A Species B 10 days of overlap

13. Species A Species B 20 days of overlap

14. Species A Species B 25 days of overlap

15. Species A Species B 30 days of overlap

16. Summary Coexistence breaks down as settlement events become more correlated between species Increasing the number of independent packets accomplishes the same result –By chance more packets => more concurrent settlement between species

17. Future Work Quantify how much overlap in spawning time can occur and still get coexistence Deal with partial correlation at edges of overlap?? Statistics from flow simulations on overlapping spawning windows (Satoshi)