Ryann E. Rossi of North Carolina State University gave a presentation on, “A Closer Look at the Mangrove Die-Off in The Marls.” Rossi first defined what a mangrove is, and listed the benefits of mangroves in terms of being a nursery habitat for marine life, land accretion and carbon sequestration.
Based on a case study carried out on Abaco, Rossi along with others set out to determine the causes of mangrove die-off from nature and humans in the Marls, which are located on the western side of Abaco.
Without a doubt, the leading cause of mangrove loss is habitat destruction by humans, however, humans have a low impact in this localized region according to the study. Natural factors such as hurricanes result in drastic mangrove loss, and insects also cause their share of damage when they damage or consume the leaves and roots of mangroves.
With dwarf Red Mangroves (Rhizophora mangle) as the focal point, the question was asked whether grazers, disease or multiple stressors contribute to die off. They also looked at the extent of plant disease with the presence of lesions on the leaves that were found in Sandy Point, North Abaco and the Marls.
After the completion of disease incidence surveys, a subset of leaves with lesions present were collected for isolation to determine the cause of the disease. The results were that the pathogen was possibly present after die off starts, and through Koch’s postulates, the testing identified a species of a fungus called Pestalotiopsis that may be the culprit. It was also discovered that leaves that have been chewed on tend to develop more lesions.
In conclusion, Rossi acknowledged all the guides and organizations involved in the research adding that the findings were reported on the Abaco Mangrove Survey, which can be found on the Abaco Scientist Blog for those who are interested in reading more information.