Coral reefs thrive on clean, clear, low-nutrient water.
But runoff from the islands contains fertilizers from farms and lawn care, and these excess nutrients cause both naturally occurring and invasive algae to go haywire.
Before you know it, all the available real estate is shellacked with fast-growing algae, and the extremely slow-growing coral can't colonize these surfaces.
Parrotfish keep these blooms in check by beak-biting straight down to the substrate.
Add to this the unfortunate fact that many species of parrotfish are also really heavy sleepers, and you can see there's a problem.
At night, they secrete a layer of mucous across their body that's thought to protect them from parasites and perhaps keep predators from sniffing them out.
"Every living thing is just looking for space, and each bite the parrotfish takes opens up an opportunity for coral larvae to settle in." Those bites are more valuable now than ever.
But it does nothing to prevent unscrupulous night divers from plucking the fishies from the reef like cooling pies off the proverbial windowsill.