Plastic rafting: the invasive species hitching a ride on ocean litter

Ocean plastic has become a route for invasive species that threaten native animals with extinction, with Japan's tsunami sending nearly 300 species rafting' across the Pacific

Japan's 2011 tsunami was catastrophic, killing nearly 16,000 people, destroying homes and infrastructure, and sweeping an estimated 5m tons of debris out to sea.

That debris did not disappear, however. Some of it drifted all the way across the Pacific, reaching the shores of Hawaii, Alaska and California - and with it came hitchhikers.