Location Isn't Everything: Timing of Spawning Aggregations Optimizes Larval Replenishment.

Area of Science:

• Marine Biology
• Ecology
• Oceanography

Background:

• Reef fish form predictable spawning aggregations.
• These aggregations may offer fitness benefits beyond mating, linked to oceanographic features.

Purpose of the Study:

• To model larval dispersal and fitness landscape for reef fish.
• To investigate the influence of spawning timing and location on larval success.
• To understand the trade-off between reproductive risk and reward.

Main Methods:

• Developed a probabilistic biophysical model of larval dispersal.
• Coupled the model with a high-resolution hydrodynamic model of the Florida Straits.
• Tracked virtual larvae from release to settlement, incorporating ontogenetic changes in behavior.

Main Results:

• Larval success was highly sensitive to spawning timing, not release location.
• Propagules released during the observed spawning period showed higher success rates.
• Minimum larval survival was maximized during the observed spawning period, reducing recruitment failure risk.

Conclusions:

• Spawning timing is a critical factor for reef fish reproductive success.
• The observed spawning period likely represents a strategy to minimize recruitment failure.
• Spawning period length may reflect a trade-off between reproductive risk and reward.