Photo: Mariko Wallen Survivorship Bleaching Disease This is easy to track with discrete colonies/units like the elkhorn cookies, harder with many staghorn branches. This photo shows ~80% survival of all the out- planted branches, in one ‘rosette’. Keeping track of which corals bleach and which do not is crucial data! Disease, bleaching and predation can be difficult to distinguish. Disease typically has a sharp line between live and dead tissue (unlike bleaching) and often starts from the base up. Coral eating snails look just like dead reef-they can often be found by their predation scar, dead and/or newly dead (white) tissue (center of photo).
Two large snails are on the edge of the dead/live tissue in the photo. Predation-Snails Predation-Snails-Identification Predation-Fire worm There are lots of different snails out there! Only the coral-eating snails have an orange operculum (their ‘foot’). Pictured are adults, they can also be very small, and there is almost never just one, but they are often hard to see/reach under branches. Typically fire worms are nocturnal, but sometimes found in the day. They may prefer staghorn, but eat all three acroporids. DO NOT touch fire worms! You need a tool to remove them (we use salad tongs). Photo: Annelise Hagan Predation-Fire worm Biodiversity-fish surveys? Spawning?
Fire worm scars on staghorn are easy to recognize: they start from the tip of the branch and go down. Either bright white (newly eaten) or algae covered tips are evidence of fire worm predation on staghorn. Fish surveys to date have been modified around the photo- mosaic plots-but this is not the only way to measure biodiversity. Have an idea? Want to know more? Ask your instructor/trainer. Spawning occurs in a short, variable window at night, after the full moon (July-September). It requires additional equipment and experience to monitor and FoH is pursuing affordable ways to use remote cameras. 16