Two children set out to capture a mermaid, but she manages to escape all of their traps.

A shark has been spotted in Trident City! Pearl Swamp is so scared, she needs a shark Guard to escort her to and from school. She doesn't trust anyone who likes these terrifying creatures, especially Kiki Coral, who isn't nearly as frightened as Pearl. And to make matters worse, Pearl accuses Kiki of stealing her precious pearl necklace! Will the sharks destroy the peace of their sparking city? Or will the mergirls have to swim in dangerous deep-sea...

"Traveling home by cruise ship should be a relaxing break after Emily's latest adventure, but things take a turn when the ship is overtaken by a pirate king and his crew. After the pirates collect everyone's riches, they steal something even more valuable: Aaron. The pirate king's eldest son takes Aaron captive, forcing him to help guide the pirates to the mythical Trident's Treasure. So Emily dives into action and joins the younger son's crew in...

Of all the creatures in the ocean, sea horses are Echo Reef's favorite. They're sweet and gentle and they glide through the water so gracefully. When Echo discovers that Rocky Ridge, one of her Trident Academy classmates, has his own pet sea horse, she wants one right away. Not everyone agrees sea horses should be pets, however. Perhaps they are happiest when swimming freely. But Echo thinks that if Rocky can make a sea horse happy, she can too! Can't...

Aqua, the mini-mermaid, takes Pinkalicious and Peter to her favorite seaside spots.

Racing to bring the magic crystals to the Coral Kingdom, the six young mermaids discover a dolphin trapped in a fisherman's net, thanks to the evil Mantora, and Sophie, the fastest swimmer, rushes off to find help.

When the arrival of Jade's first period includes the appearance of scales and a tail, she discovers she's inherited her mermaid tendencies from her late mother, and it prompts her to investigate how her mother died.

Ariel is a mermaid who always wanted to explore life on land. After making a deal with the sea witch, Ursula, Ariel has a chance to go to the human world. There she meets Prince Eric, who takes her on an adventure around his island village. Will Ariel be able to break Ursula's enchantment and find her voice before it is too late?

Misty and five fellow mermaids, on a quest to retrieve six magic crystals that will protect the Coral Kingdom for the next year, face a storm sent by the evil Mantora and are driven off-course to the Kelp Forest, where they find a different kind of trouble.

The six young mermaids are delayed on their vital mission to bring magic crystals back to the Coral Kingdom by an oil spill created by the evil Mantora, as Ellie seeks the special ingredient for a potion that will help save birds caught in the oil.