A diver swimming over a bed of Caulerpa. Credit: Irene Middleton, Biosecurity NZ

Examining the movements of vessels between locations helped to predict where an invasive seaweed spread, researchers led by the Australian Institute of Marine Science (AIMS) have revealed. Invasive Caulerpa species (Caulerpa brachypus and Caulerpa parvifolia) are a major concern in New Zealand's coastal areas, spreading rapidly via boat gear or anchor entanglement, and causing long-lasting ecological and economic damage.

Documented in two research papers, scientists created tools to map how vessel movements connect different parts of the coast, then applied that framework to the spread of Caulerpa.…