Watch: Nylon, polyester, rayon, and other synthetic plastic fibres are being blamed on microplastics being found at every site tested at Lake Wānaka. Credits: Newshub. Fast fashion is being blamed in part for a shocking discovery in Lake Wānaka. Sampling of the waters of the beautiful South Island tourist spot has found microplastics at all 10 sites and it's prompted a call for Kiwis to be more conscious of their clothing choices.