Galveston Island’s residents notice subtle changes to our coast as colder weather moves in: less tourists, less risk of hurricanes and good fishing are some of the things we look forward to. Have you seen the White Pelicans congregating near Pier 19 and the Ferry Landing? They migrate here every year when their breeding grounds near the Great Lakes freeze over to enjoy our mild winters and abundant waters. In this picture you can see one enjoying the bounty of the Flounder run, once he can figure out how to swallow it!.
Our wetlands serve vital ecological functions, and they are getting increased visits from another migratory species, the Black Mangrove, (Avicennia germinans), a species that historically struggled to survive here because of our periodic winter cold snaps. These freezes were often intense enough to kill off young mangroves before they ever had the chance to establish. Now with warming temperatures, AKA tropicalization, these resilient shrubs are beginning to establish themselves.
Sandhill Cranes are another migratory species, a true Snow Bird that prefers open marsh and may avoid mangrove-dominated areas. Some worry that mangroves could outcompete native saltmarsh plants like Spartina alterniflora and alter important wetland habitats. Others argue that a mix of mangroves and saltmarsh plants creates a stronger, more diverse coastal ecosystem.
Ecological Restoration practices are designed to improve the balance between native and nonnative species, oftentime removing invasive species, but what happens on our shifting sandbar of an island when you remove a plant that does a great job stabilizing the shoreline?
We interviewed one of the leading research scientists on this topic, Dr. Anna Armitage, and this is what she had to say, “Our lab studies how mangrove and marsh plants are similar and different … Research from our lab has shown that a diverse mix of marsh and mangrove plant species provides the most benefits for local communities and economies.”
So what do you think? Are black mangroves a welcome addition, or do they pose challenges for local species and marsh communities?
Check out Dr. Armitage’s research here!