Multiscale flow between the branches and polyps of gorgonians

Area of Science:

• Marine Biology
• Fluid Dynamics
• Biophysics

Background:

• Gorgonians, or sea fans, possess intricate branching structures influencing ocean currents.
• These structures are hypothesized to optimize feeding by altering flow velocities and prey capture.

Purpose of the Study:

• To quantify gorgonian morphology across multiple scales (branches, tentacles, pinnules).
• To analyze fluid dynamics and flow patterns around gorgonians using computational methods.
• To determine how gorgonian structures affect plankton capture efficiency.

Main Methods:

• Quantification of gap-to-diameter ratios at branch, polyp tentacle, and pinnule scales.
• Computational fluid dynamics (CFD) simulations to model flow patterns.
• Agent-based modeling to simulate plankton capture.

Main Results:

• Gorgonian branches and tentacles can function as leaky rakes or solid plates based on flow parameters (Reynolds number, gap-to-diameter ratio).
• Pinnules primarily obstruct flow.
• Plankton capture rates are highly sensitive to gorgonian morphology and flow conditions.

Conclusions:

• Gorgonian morphology significantly influences flow dynamics at various scales.
• The interplay between morphology and flow conditions is critical for gorgonian feeding and nutrient exchange.
• Findings provide insights into the ecological roles of gorgonians in modifying marine environments.