How do marine species travel the world? Ocean currents act as “highways” for marine life, moving larvae, individuals, and genetic material between populations.

But understanding these connections on a global scale, and how they shape biodiversity, has been almost impossible. We generated the first-ever global estimates of ocean current connectivity, tracking 204 million particles over 21 years. This new dataset is a benchmark for marine conservation and climate change resilience.

Knowledge gap

Despite its importance, a comprehensive, high-resolution global dataset of oceanographic connectivity has been missing. Traditional studies often rely on overly simple models that fail to capture the complex, variable, and asymmetric dispersal patterns created by real-world ocean currents. This knowledge gap has hindered our ability to understand species’ dispersal and develop effective large-scale conservation strategies, especially for building resilience to climate change.

Main approach

We tackled this gap by creating the first comprehensive dataset of connectivity estimates (both probability and travel time) along all the world’s coastlines. We used a robust biophysical model that simulates passive dispersal, essentially tracking “virtual larvae” carried by ocean currents.

Technological challenge - how we tackle the study

The scale of this challenge was immense. Our model used 21 years of daily, high-resolution global ocean current data (GLORYS12V1). We released particles daily from 26,642 coastal sites worldwide, running Lagrangian simulations to track over 204 million individual particle trajectories. To make this massive dataset (which includes 195 million recorded connectivity events) accessible and useful, we also developed coastalNet, an R package designed to streamline the access, analysis, and visualization of the connectivity data.

Main finding

The result is a new, publicly available benchmark dataset for oceanographic connectivity research. It provides pairwise probabilities and travel times between coastal locations, which can be flexibly combined with species-specific biological traits. Researchers can now filter the data by planktonic duration (from hours up to 180 days) and by seasonality (spawning periods) to create realistic dispersal models for thousands of different marine species.

Main implications

This dataset is a powerful new tool for marine conservation and management. It provides the critical data needed to:
Inform more effective conservation strategies, such as designing and assessing networks of Marine Protected Areas.
Understand and predict species’ resilience and potential for range expansion under climate change.
Enable a deeper exploration of the complex dynamics that shape coastal marine ecosystems.
Calculate multi-generational “stepping-stone” connectivity, identifying crucial pathways for dispersal over long distances.