An Urchin Matter

Plot:

There's a mega mystery in Megabays - the once-healthy kelp in Big Bay is washing ashore. The CyberSquad must work with Captain Skuttlebutt, keeper of the bays, to get to the bottom of it. They explore the marine ecosystem and discover that there are way more urchins than anything else... but why? Is it nature at work, or is something - or someone - causing the underwater kelp forest's collapse?