Paddling my way along the Florida Keys during today's kayaking adventure I enjoyed taking in the beautiful scenery of the red mangroves that lined the shores. As I slowed down, though, to observe my surroundings I couldn't help but notice that some of the trees must have been disease ridden. Along the trunk and branches, darkened, almost black lumps with a crackled texture formed on the surface of the bark.
I wondered what could be causing such an awful sight to these once beautiful trees, so out of curiosity I decided to look into this further. Could it be lethal to the tree? Are other surrounding plants likely to become infected as well? What is even causing this to happen? Is it an insect? A fungus? Bacteria?
Red mangroves are one of the most abundant species in southern Florida. Rhizophora mangle are found all along the peninsula, extending from the Gulf coast to the Atlantic coast. They are found along the edges of the water and are known for their complex root systems, consisting of drop and prop roots.
This species is ecologically important, in that it provides other organisms with shelter, food, a place to mature to adulthood, soil stabilization against erosion, and buffers during hurricanes. They are also economically significant because of their direct impact on commercial and sport fishing.
Not much is known about diseases that could infect red mangroves in Florida. There is, however, a study done on a gall disease caused by a fungus called Cylindrocarpon didymum that is very similar to a gall disease that affects Rhizophora spp. of West Africa. It tends to cause galls that range from 1-20 centimeters in diameter along the trunks, branches, and prop roots. Bark on the surface of the galls is usually darkened and rough, especially as the tree ages. Galls that develop are believed to be caused by a type of acid the fungus produces. So far, mortality from the disease has been minimal, however, they could cause trees to be prone to breakage where infections are more abundant and severe.
No control measures have yet to be set. Since this species of mangrove is so significant from both an ecological and economical standpoint, it's important to get the fungal infection under control. Additional research is needed to effectively set a plan to save the red mangroves from becoming disease ridden.
This is very interesting and should definitely be studied to figure out why this is happening and find a possible solution to prevent this from effecting the red mangrove species.
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