Effects of Marine Debris on Open Ocean Biodiversity

Abstract:

Millions of tons of plastic debris enter the oceans each year and affect marine biodiversity by a variety of mechanisms. In recent years, it is increasingly clear that the large-scale flux of floating macroplastic debris across oceans acts as artificial rafts, transporting coastal species to new locales thousands of miles from their native ranges. Following the 2011 East Japan Tsunami, over 300 coastal species survived transit from Japan to western North America and Hawaii, with evidence of some persisting in the open ocean for up to a decade. Our interdisciplinary research combines ecology and oceanography to understand dynamics of this novel floating ecosystem, focusing on the biodiversity, demography, and movement of coastal marine invertebrates on macroplastic debris found within the North Pacific Subtropical Gyre (NPSG) – the area of highest plastic accumulation in the ocean. Here, we present results of sampling biodiversity of benthic invertebrates on floating debris in the NPSG, testing the role of plastic debris as a platform for sustained coastal populations in the open ocean and exploring the implications for invasive species transport and endemic open ocean communities. We highlight the roles of processes of disparate spatial scales (from thousands of kilometers to meters) in transport and community dynamics associated with this floating ocean ecosystem, and discuss the present capability of and future need for in situ observations and satellite products to assist description and predictions of the floating ecosystem.