I can see it in a couple of years after the primordial plastigoop sea has filled the void.

Plasticous Perca flavescens laying their long strands of elastic plastic eggs on the cribs.

PVC Micropterus dolomieu guarding their poly predator babies over the inverted plastic mushroom tops.

Lepomis Polyvinylus microlophus crunching on thin polyshell snails with their thermoplastic polymer pharyngeal crusher plates.

Poly Pimephales promelas inside the Brettski logs nesting with their plasticizer tubercles emitting a sticky ooze.

All the while the first polyvinylphibians who through the thermal depolymerization process can safely and efficiently convert PVC into fuel and minerals ,are bravely marching toward the land and being consumed by the poly goop fish on their way. Sounds kinda like someone fishing with a plastic lizard !!