In this drawing fishes represent marine life and this shows how food chain goes on by small fishes being eaten by big ones. But usage of plastics and throwing garbage into water bodies lead to loss of their lives and also causes imbalance in the biodiversity. 
So, I would say if one cannot stop using plastics at least reduce its usage. Instead of searching life on other planets we should conserve “PLANET EARTH” where life already exists.

Efforts by – Gyana