Hydrodynamic provinces and oceanic connectivity from a transport network help designing marine reserves

TL;DR

This study introduces a network-based approach to analyze oceanic dispersal and connectivity in the Mediterranean, aiding the design of marine protected areas by identifying hydrodynamical provinces and connectivity patterns.

Contribution

It couples Lagrangian transport modeling with Network Theory to delineate hydrodynamical provinces and assess marine connectivity for MPA planning.

Findings

Hydrodynamical provinces match multi-scale oceanographic features.

Connectivity metrics reveal spatial scales influencing larval dispersal.

Network analysis informs MPA design and marine biogeography understanding.

Abstract

Oceanic dispersal and connectivity have been identified as crucial factors for structuring marine populations and designing Marine Protected Areas (MPAs). Focusing on larval dispersal by ocean currents, we propose an approach coupling Lagrangian transport and new tools from Network Theory to characterize marine connectivity in the Mediterranean basin. Larvae of different pelagic durations and seasons are modeled as passive tracers advected in a simulated oceanic surface flow from which a network of connected areas is constructed. Hydrodynamical provinces extracted from this network are delimited by frontiers which match multi-scale oceanographic features. By examining the repeated occurrence of such boundaries, we identify the spatial scales and geographic structures that would control larval dispersal across the entire seascape. Based on these hydrodynamical units, we study novel connectivity metrics for existing reserves. Our results are discussed in the context of ocean biogeography and MPAs design, having ecological and managerial implications.