It’s the 1980s and the Teenage Mutant Ninja Turtles franchise has burst onto the scene, scoring millions of young fans.  

Half-human, half-turtle fighters Donatello, Leonardo, Raphael and Michelangelo originated as comic book characters before spawning phenomenally popular films and cartoons.  
But “turtlemania” also inadvertently sparked a pet craze that ultimately led to an invasive species problem.  
Red-eared terrapins were a particularly popular pet. But many people didn’t realise they would grow from a matchbox-sized hatchling to a dinner-plate sized adult that lives for more than 40 years.  
   
As a result a significant number of fres...