North Pacific Subtropical Gyre 2018–2019 invertebrate biodiversity on macroplastic

We show that the high seas are colonized by a diverse array of coastal
species, which survive and reproduce in the open ocean, contributing
strongly to its floating community composition. Analysis of rafting
plastic debris in the Eastern North Pacific Subtropical Gyre revealed 37
coastal invertebrate taxa in total, largely of Western Pacific origin,
exceeding pelagic taxa richness by three-fold. Coastal taxa, including
diverse taxonomic groups and life history traits, occurred on 70.5% of
debris items. Most coastal taxa possessed either direct development or
asexual reproduction, possibly facilitating long-term persistence on
rafts. Our results suggest that the historical lack of available substrate
limited colonization of the open ocean by coastal species, rather than
physiological or ecological constraints as previously assumed. It appears
that coastal species persist now in the open ocean as a substantial
component of a neopelagic community sustained by the vast and expanding
sea of plastic debris.