Mangrove channels have an amazing amount of marine life. They're very valuable to the health of the ecosystem and surrounding marine life. Mangroves are also what keeps much of Florida from washing away during hurricanes. It's the restoration of the mangrove marshes that surround Tampa Bay that are largely responsible for the overall improvement of the area over the last few decades. There's still a lot of work to be done, but the area has dramatically improved. Almost the entire bay is surrounded by protected Mangrove marshes.
