UNIVERSITY OF CENTRAL FLORIDA
A number of volunteers work among the pots and children’s swimming pools filled with mangrove seedlings. The plants will stay at this mangrove nursery until they
are ready to be planted along the shores of the Indian River Lagoon.
WINTER 2022: 67
the saline water. Blacks are the tallest of the mangroves,
sometimes reaching 15-20 feet high. Their wood has been used
as a building material.
According to Donnelly, the majority of Florida mangrove loss
in the last 30 years has been due to human activities, but
not all of it. Mangroves thrive in the temperate and tropical
zones, but are intolerant to cold weather. A series of hard
freezes in the 1980s wiped out much of the mangrove cover in
Donnelly says large scale mangrove restoration has occurred in
the last 20 years. But restoring mangrove shorelines can be hard
work. Some restoration projects report less than a 50% success
rate in replanting efforts. Donnelly’s group has come up with a
replanting process that yields a much higher rate of success.
Using Donnelly’s system the shoreline is first protected by
several feet of bagged oyster shells to buffer wave action.
Behind the oysters are wetland grasses Spartina alterniflora,
which further protect the intertidal area. Mangroves are then
planted behind the grasses in different rows. First, the red
mangroves, then the whites and finally the blacks. Donnelly
says their success rate is 85% or higher.
Another mangrove project leader, Caity Savoia of the Marine
Resource Council, reports breakwater efforts work really well in
the replanting process.
“Some sites had zero percent success rates,” she says.
But behind the breakwaters the rate has been up to 100%. She
laments not having enough natural shorelines left to replant,
due to development in the coastal areas along the lagoon. She
estimates 65% of the natural shoreline in Florida’s Indian River
Lagoon in Brevard County has been lost behind seawalls and
The Marine Resource Council is planting mangroves along
the lagoon shore in Palm Bay. It has a nursery for mangrove
seedlings in Palm Bay and another in Vero Beach.
When people think of trees in Florida, palm trees usually come
to mind first. But it is the mangrove that is most important to