agua basura bubble can coast debris dumped garbage h2o mar plastic plastico pollution rock sea sea weed seaweed water water pollution dead fish flies fly grass insect polluted rot estuary mudflat pollute rubber rubbish spoil tire tyre waste waterweed weed advice alert appropriate behavior appropriate behaviour avoid black care concern danger dangerous denied directions not allowed not permitted permission denied prohibited prohibition protect protection red rules safety sign signs toxic toxicity warning warning sign water toxicity weathered white worn abandoned boot brown dirty half left lonely Mud water boot circle old rocks round useless Dirt environment environmental conservation environmental protection flowing water lake nature river sand turbulence unhygienic bird dock Heron industry manmade oil pier ship shore