Chapter 08: Vulnerability of seagrasses in the Great Barrier Reef to climate change

Abstract

Seagrasses are flowering plants and, along with mangroves, have greater affinities to terrestrial plants than other marine macrophytes such as algae. Approximately 55 species of seagrass occur in five different plant families and represent at least three independent evolutionary lineages. Thus, seagrasses are not a taxonomically unified group but a ‘biological’ or ‘ecological’ group85,149. The evolutionary adaptations required for survival in the marine environment have led to convergence in morphology. Seagrasses evolved under differing ambient CO2 and temperature conditions so may have different tolerances to changing environmental conditions. A wide range of tolerances across marine environments exist amongst the extant diversity of seagrasses, reflecting their substantial adaptive capacity as a group.