Title: THE PERFECT STORM: MATCH-MISMATCH OF BIOPHYSICAL EVENTS DRIVES LARVAL FISH CONNECTIVITY BETWEEN PULLEY RIDGE MESOPHOTIC REEFS AND THE FLORIDA KEYS

Abstract: Mesophotic coral reef ecosystems are remote from coastal stressors and may be the key to resilience. While they remain for the most part exposed to fisheries overexploitation, nothing is known so far about larval fish connectivity between mesophotic and shallow ecosystems. We use a biophysical model to test the hypothesis that Pulley Ridge, a mesophotic reef in the Gulf of Mexico that hosts a variety of shallow-water tropical fishes, may replenish shallow fish populations in the Florida Keys. To identify spatio-temporal patterns of vertical connections we developed a 3-D coral reef habitat module for the open-source Connectivity Modeling System and simulated larval transport of a demersal spawner, the bicolor damselfish Stegastes partitus. Virtual larvae were released daily between 60-80m from Pulley Ridge over 60 lunar spawning cycles, and tracked until settlement within a high resolution (900 m) regional hydrodynamic model. These probabilistic simulations reveal mesophotic to shallow connections with large, yet sporadic pulses of larvae settling in the Florida Keys. Modal and spectral analyses on the spawning time of settled larvae, and on the position of the Florida Current front along Pulley Ridge, demonstrate that specific physical-biological interactions modulate these “perfect storm” events. This study demonstrates that mesophotic coral reef ecosystems can also serve as refugia for coral reef fish and suggests that they have a critical role in the resilience of shallow reef communities.

Authors: Ana CV, Paris CB, Olascoaga MJ, Kourafalou VH, HeeSook K, Reed JK

Presentation: Oral

Session: 15

Date: 06/23/16

Time: 15:15

Location: 317 A/B

Back