Crackle, pop, woof, crunch, click. In the ocean, an undersea orchestra is in full swing. Journalist Kate Evans discovers who's playing in it and why, and what happens when human noise drowns out this symphony in the sea.

Kina numbers are exploding on some of our reefs, decimating seaweed habitats. Could this problem be solved by eating them? Kate Evans investigates the potential of kina-nomics.

People and livestock gobble so much fish that the seas soon won't keep up. Is the answer to grow fish on land? Kate Evans meets scientists figuring out the puzzles of how to farm some of New Zealand's iconic ocean creatures.

What roles do our ocean ecosystems play in capturing carbon? Kate Evans speaks to iwi Māori working to improve the health of an estuary in the Bay of Plenty, and to scientists studying the fiords of New Zealand's southwest coast. There's potential for huge amounts of carbon to be locked away, if we don't mess it up. 

The Bounty Islands are tiny in terms of area - just some bits of granite jutting out of the ocean. But they are huge in terms of seabirds. James Frankham joins a team researching the erect-crested penguins who breed in this remote archipelago. Recent counts suggest the penguins of the Bounties are doing fine. But this is not the case on the Antipodes Islands, and the researchers desperately want to know why.

New Zealand once led the world in marine protection. Now it looks like we will fail to meet our international promise to protect 30 percent of our ocean estate by 2030. Why is stopping fishing so politically fraught? How might our ideas about marine protection need to change? And why, when our seas are in need, is it taking us so long to learn to talk to each other?

Journalist Rebekah White meets two people who have been counting albatrosses on remote islands in the subantarctic for more than three decades. Their research shows that at least one species is en route to extinction. A few changes to the way we fish could save it.

Kate Evans visits a passionate team as they carpet a remote volcanic island in Tonga with poisoned bait, hoping to eradicate rats. What does it take to complete this kind of project, what are the chances of success, and what will it mean for the island's ecosystems if they manage to remove the rats once and for all?