stephanie schopmeyer, a university of miami marine biologist, is working to save them. >> over the pastyears, we've seen a drastic declines in coral cover, and it's mostly been due to climate change. >> reporter: we set out with schopmeyer to see the "rescue a reef" program in action. scientists, who are certified divers, are replanting parts of the reef with the help of "citizen scientists." >> citizen scientists are members of our local community that are interested in participating and contributing to any type of science program, and in our case it's coral restoration. >> reporter: and you have a waiting list? >> we have a waiting list. >> reporter: the first task is to collect recently grown coral from these so-called trees the group has installed just off key biscayne. once they bring them up, the divers are taught how to secure the harvested coral onto the ocean floor. >>> pull that zip tie as tight as you can. >> reporter: then, it's time to find a spot to re-plant them. and doing that is like underwater gardening. putting down stakes and securing the new coral, all while trying

that reef is disappearing says university of miami marine biologist stephanie schopmeyer. >> over the past 30 to 40 years we have seen them disasically not recovering, changes in the whatter chem cree, overfishing, pollution. >> quijano: . >> reporter: if ten years parts have lost nearly half the coral. they she is with rescue the reef. >> how important is that to what you do? >> it's very important. any time a citizen scientist comes out with us, we are able to put more corals on the reef than we would normally be able to. >> reporter: it's like underwater gardening. they harvest newly grown coral from one part near key biscayne to transplant to another securing them to the ocean floor. planting them is a delicate time-consuming process. >> here we're doing a stress test. >> biologist ross kunning is monitoring the survival rate. >> we're trying to identify which corals are able to withstand warming temperatures. >> reporter: billions of dollars are at stake from fishing to tourism. the reef also helps protect against beach he roques-- erosion and another major threat hurricanes. >>