The Urchin Invasion (S03E18)
S03E18
The Octonauts journey to the kelp forest to see Shellington's sister, Pearl, and her new baby, Periwinkle. However, they soon discover that the kelp forest is under threat from a swarm of urchins that are munching away at the kelp!
Show
Octonauts
Episode
S03E18
Air Date
Mar 21, 2014
Season 3 Episodes
S03E01
The Siphonophore
S03E02
The Water Bears
S03E03
The Cone Snail
S03E04
The Artificial Reef
S03E05
The Humpback Whales
S03E06
The Pelicans
S03E07
The Sea Pigs
S03E08
The Yeti Crab
S03E09
The Barracudas
S03E10
The Duck-Billed Platypus
S03E11
The Sea Skaters
S03E12
The Mudskippers
S03E13
The Harbour Seal
S03E14
The Lion's Mane Jellyfish
S03E15
The Red Rock Crabs
S03E16
The Sea Sponge
S03E17
The Immortal Jellyfish
S03E18
The Urchin Invasion
S03E19
The Hammerhead Sharks
S03E20
The Loggerhead Sea Turtle