Invasive alien species modify entire ecosystems, damage biodiversity, and instigate economic and environmental harm. Due to these impacts and the fact they are often impossible to eradicate once established, they are consequently the second major reason for species extinctions. Dikerogammarus villosus, given the epithet of "Killer Shrimp", are one of the most successful invaders of recent times and were discovered in 2012 to have contaminated the fragile ecosystem of the Norfolk Broads. This study maps their distribution throughout different regions of the Broads to observe their dispersal and examine their effects on the native shrimp Gammarus pulex. This research shows the killer shrimp have established themselves throughout Barton Broad, Turkey Broad, and River Ant overpowering the native shrimp and diminishing their numbers.