The first day of the 7th biennial ASAC meeting has come to an end! Here is a link to the talk about the mangrove die-off in The Marls: A closer look at a mangrove die-off
We will post more talks and posters from ASAC as they come in so stay tuned!
The first inoculation trial was successful in that we were able to re-isolate the fungus (Pestalotiopsis) we infected leaves with from small, developing lesions. The second trial is underway and as you can see from the feature image, we are seeing similar lesion symptoms we see in the field in the lab. We have to re-isolate from this lesion […]
We posted last week about Pestalotiopsis and the role it may play in generating the lesions on Red Mangrove leaves we’ve documented. Here are some photos that show part of the process involved in determining if Pestalotiopsis is the causal agent of the lesions. In short, leaves from Red Mangroves showing no symptoms of lesions were plucked from the seedlings […]
Using DNA sequencing and morphological identification, we have established that a species of Pestalotiopsis could be the culprit behind the lesions. While a handful of different species of Pestalotiopsis have been identified on Red Mangroves in Florida, Bermuda, and China, most of these documentations identified species as saprobes (the fungus lives on decaying material) or endophytes (the fungus lives inside […]
1. This die-back appears to be the result of multiple stressors acting together. Think of it in the sense of our own body- when our immune system is down, we are often more susceptible to getting sick. The same thing is likely happening to the mangroves.
2. It appears as though a fungal disease may be taking advantage of already stressed […]
Here are some photos of our recent course we did with Friends of the Environment focused on shark ecology and conservation. This two day course was inspired to help educate students on the importance of the recent shark ban that prohibits commercial shark fishing and promotes a catch and release recreational program nationwide here in The Bahamas. Further, the course went […]
Last year I set up cages in The Marls to tease apart the role insect grazing could play in the die-off of dwarf red mangrove in The Marls. I have kept the experiment going since last May and hope to keep it running for as long as I can. I will post with an update on what the data […]
With the help of Dr. Chandra Giri of the US Geological Survey, we have begun to map the mangrove die-off in the Marls. Using Landsat images, or high resolution satellite images, and principles based on the optic properties of healthy vegetation we can calculate an index called the Normalized Difference Vegetation Index, or NDVI. NDVI ranges from -1 to 1 […]
Good news! We have likely identified one fungal species that may lead to the lesions we have seen on the mangrove leaves. Preliminary data suggest that a Pestalotiopsis species (an Ascomycete fungus) may be a player in generating the lesions we see on the leaves in The Marls. Interestingly, this species has been found to cause leaf spots in Florida.
Here are some preliminary photos of fungal isolations from mangrove leaves from The Marls. We are working on identifying and generating pure cultures of these samples, but there is certainly fungi present on the leaves exhibiting lesions. We will update you as we find out more!