SCALLOPED HAMMERHEAD SATELLITE TAGGING MAY 2025

On May 4, 2025, after three years of research and development, Twin Oceans Research Foundation successfully satellite tagged a mature female scalloped hammerhead shark in the coastal waters near Chame, Panama. We named her Shannon Rain in honor of the three rain-soaked nights that culminated in her safe tagging.

From the moment the tag was activated, Shannon Rain began transmitting valuable geolocation data via satellite each time she surfaced. This marked the first time a scalloped hammerhead shark had been satellite tracked along this route from Panama into the Eastern Tropical Pacific Corridor.

Key Movement Data (as of June 8, 2025):

• Total Distance Traveled: Over 1,300 kilometers
• Current Position: Approximately 300 kilometers from the northern Galápagos Islands
• Likely Destination: Either Darwin Island or Wolf Island
• Travel Rate: Averaging ~2.5 km per hour during active migration
• Surface Intervals: Multiple uplink transmissions have confirmed consistent surfacing along the migration corridor

Her trajectory has aligned with known but previously unproven theories of seasonal movement through Cocos Ridge and the underwater seamount corridor leading toward the Galápagos. Her location updates show a clear directional path, strengthening the hypothesis that scalloped hammerheads born in or near Panamanian waters are part of a larger migratory population that returns to offshore aggregation and potential mating sites around Darwin and Wolf Islands.

Behavioral Insight:

Shannon Rain’s route suggests a purposeful and uninterrupted migration—likely instinctual, possibly hormonally driven toward breeding grounds. Surface behavior, as indicated by tag uplinks, shows predictable surfacing patterns every 1–2 days, often during early morning or late afternoon hours. This may reflect resting intervals, navigation behavior, or temperature regulation.

The shark's movement also coincides with seasonal upwelling patterns and plankton blooms, offering insights into possible ecological drivers of migration.

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