Hereiti, 17, lives on Rarotonga, the largest of the Cook Islands in the South Pacific Ocean.
The research by The Ocean Cleanup suggests ocean plastic pollution comes from more rivers in the world than previously thought.
Many companies want to exploit deep sea minerals but campaigners warn it could damage fragile ecosystems.
Marine scientist Professor Jessica Meeuwig on her hopes for a new ocean monitoring system.
Covid border closures mean hundreds of thousands of sailors are being prevented from returning home.
In 1960, Jacques Piccard and Lieutenant Don Walsh became the first humans ever to journey to the world's greatest depth, the bottom of the Mariana Trench in the Pacific Ocean.
An officer on board the ship shot at the 8ft-long shark to deter it from attacking the crew members.
Environmentalists are concerned about over fishing of shark and tuna populations
By Victoria Gill
Science correspondent, BBC News
Scientist and ex-astronaut Kathy Sullivan is the first woman to reach the lowest part of the ocean.
By Jonathan Amos
BBC Science Correspondent
By Kelly-Leigh Cooper
By Rebecca Henschke
BBC World Service
By Ben Philip
The USS Nevada was the only ship to be present at both D-Day and the attack on Pearl Harbor.