A comprehensive review of Gracilaria vermiculophylla invasion along the east coast of the United States—Current knowledge and future directions

Gracilaria vermiculophylla, a red macroalga native to the Northwest Pacific, is now widespread in coastal estuarine ecosystems along the East Coast of the United States. Its broad environmental tolerance, high capacity for asexual reproduction via fragmentation, and ability to alter habitat structure have allowed it to persist and thrive, often outcompeting native macrophytes. This review synthesizes 48 studies on G. vermiculophylla from the East Coast of the United States, categorizing them into nine research areas: (1) Habitat Formation and Alteration; (2) Trophic Dynamics and Grazer Interactions; (3) Impacts on Nutrient Cycling and Biogeochemical Processes; (4) Microbial and Microalgal Interactions; (5) Responses to Climate Change; (6) Population Genetics; (7) Chemical Ecology; (8) Economic Impacts; and (9) Restoration and Management Implications. Although ecological and physiological studies dominate the literature, applied research on management, climate change impacts, and socio-economic outcomes remains limited. Addressing these knowledge gaps will require interdisciplinary approaches that link ecological, social, and economic dimensions to better develop effective management strategies. Effective management of G. vermiculophylla on the U.S. East Coast will require adaptive, context-dependent strategies that account for local habitat conditions, reproductive mode, and trade-offs between localized functions and the loss of native ecosystem services.