Modeled Population Connectivity across the Hawaiian Archipelago

Area of Science:

• Marine Biology
• Oceanography
• Ecological Modeling

Background:

• Coral reefs are vital marine ecosystems facing threats.
• Understanding connectivity is crucial for conservation and management.
• Previous studies lacked comprehensive connectivity estimates for the Hawaiian Archipelago.

Purpose of the Study:

• To provide the first comprehensive estimate of passive pelagic particle connectivity across the Hawaiian Archipelago.
• To identify areas of limited connectivity within the archipelago.
• To compare modeled connectivity with existing genetic data for coral reef species.

Main Methods:

• Utilized a Lagrangian particle transport model.
• Coupled the particle model offline with ocean currents from the MITgcm model.
• Analyzed connectivity matrices to determine dispersal patterns and breaks.

Main Results:

• Revealed a high degree of self-recruitment within coral reef habitats.
• Observed directional dispersal of passive particles towards the northwest, from the Main Hawaiian Islands (MHI) to the Northwestern Hawaiian Islands (NWHI).
• Identified three predicted connectivity breaks in the archipelago, particularly in the central and northern regions.

Conclusions:

• Modeled connectivity patterns align well with genetic structure in the uninhabited Northwestern Hawaiian Islands (NWHI).
• Passive dispersal alone does not explain genetic breaks observed in the Main Hawaiian Islands (MHI).
• Anthropogenic impacts on the MHI may influence connectivity, suggesting factors beyond passive transport are critical.