Introduced marine macroalgae: new perspectives on species recognition and distribution in New Zealand

Abstract

Abstract The recognition of non-indigenous marine macroalgae in New Zealand and the potential pathways and vectors contributing to their arrival were discussed by Nancy Adams in 1983 along with a list of 14 species she considered to be “possibly naturalised”. In the following 38 years many more species have been identified as non-indigenous, a few of which have become widespread and invasive around New Zealand. We present an updated list of 61 taxa that we consider to have been introduced to the archipelago, and highlight a range of issues associated with the recognition of non-indigenous species, particularly increased taxonomic knowledge, the impact of an expanded collection baseline, as well as targeted investigations in New Zealand, increasing data availability globally, and the role of molecular tools for confirming species identifications and distinguishing cryptic species.