Laguncularia racemosa, the White Mangrove.
It would be repetitious to review the background of how two people want to “SHUT SPOONBILL DOWN.”
Click here for background information:
Perhaps their most serious allegation is that White Mangroves from Spoonbill Marsh are causing the growth of White Mangroves in the Indian River Land Trust (Land Trust) salt marsh. We do not believe this to be true and invite you to consider the following.
“White Mangrove (Laguncularia racemosa) is found along the shores of Florida. They grow throughout the Indian River Lagoon well above the high tide line, generally upland of other mangroves and associated species. However, they can be found intermingled with the Black mangrove, Avicennia germinans. Their distribution… predominantly occurs…along the Lagoon, including the spoil islands, tidal creeks and mosquito impoundments.
In the Indian River Lagoon, Laguncularia racemosa, the White Mangrove, is one of three true species of mangroves commonly occurring along shorelines. The other two species are the red mangrove, Rhizophora mangle, and Lumnitzera, the black mangrove.”
According to Jenny Staletovich of the Miami Herald: “It turns out that not all mangroves — coastal trees Florida wildlife managers have taken great pains to protect — are good.
The Lumnitzera, which looks nearly identical to Florida’s native Laguncularia racemosa, white mangrove, invaded nearby Matheson Hammock Park. Botanists suspect the tree’s buoyant seed pods floated down old mosquito ditches beyond garden borders. Eventually, the infestation covered 20 acres, with mangroves popping up in clusters inland and extending north, nearly reaching the main park road that winds along a canal leading out to Biscayne Bay and beyond.”
Another problem with the White Mangrove is that it has a different root structure with no visible aerial root systems like the Red and Black Mangroves that trap and cycle various organic materials, chemical elements, and important nutrients in the coastal ecosystem. Because of their root structure, the Red and Black mangroves provide physical habitat and nursery grounds for a wide variety of marine organisms.
Red Mangrove root structure compared to White Mangrove, shown above.
Now to the allegation that White Mangroves growing in the Land Trust property come from Spoonbill Marsh.
To begin with, where do the seeds actually come from and how do they reproduce?
“Seed pods germinate while on the tree, so they are ready to take root when they drop. If a seed falls in the water during high tide, it can float and take root once it finds solid ground. If a sprout falls during low tide, it can quickly establish itself in the soft soil of tidal mudflats before the next tide comes in. A vigorous seed may grow up to two feet (about 0.6 m) in its first year.” AMNH.org
The little seedlings, called propagules, can be swept away by the ocean current. Depending upon the species, propagules will float for a number of days before becoming waterlogged and sinking to the muddy bottom, where they lodge in the soil.
Here is a map of the Land Trust and Spoonbill Marsh. The horizontal line between the Indian River land Trust and Spoonbill Marsh is the Florida Department of Transportation (FDOT) Ditch #3.
Water from the Indian River Lagoon flows into the ditch, as does storm water from Route 1.
[It so happens FDOT Ditch #3 has not been cleaned in years by FDOT despite repeated urging by the Indian River County Utilities Department.]
Quoting from above, “Their distribution… predominantly occurs…along the Lagoon, including the spoil islands, tidal creeks and mosquito impoundments.”
White Mangrove seeds, propagules, floating in the Lagoon taking root in spoil islands also float up FDOT #3; and particularly with a high-tide, float onto Land Trust property where they take root.
The spoil islands are beginning to be overrun by White Mangroves.
White Mangrove propagule
The reason the White Mangrove propagule are so quick to root is that it already has a built in root as it floats, to hook into the soil.
This process of the White Mangrove traveling up FDOT Ditch #3 to root in the Land Trust is the same way the White Mangroves have invaded Spoonbill Marsh.
The White Mangroves in the Indian River Land Trust didn’t come from Spoonbill Marsh. Their seeds came floating in from the Indian River Lagoon into FDOT Ditch #3.
In conclusion, we believe that even if Spoonbill Marsh didn’t exist, the Land Trust would still be having the same problems from FDOT Ditch #3.