Coastline ecosystems are resilient, and the mangrove species that inhabit them are well-suited to deal with harsh, stresses such as anoxic soils and fluctuating salinity. Mangrove leaves are specialised plant structures that enable them to preserve their photosynthetic capability and functionality despite frequent changes in their habitats. Along the coastline of Guyana, we studied the morphological characteristics and chlorophyll content of 400 leaves taken from Laguncularia racemosa (white mangrove) trees in one degraded and one restored ecosystem. The closest individual sampling method was used to collect leaf samples throughout the wet and dry seasons. Our results demonstrate that L. racemosa leaves are affected by both habitat type and seasonality. The leaves of L. racemosa are mesophyllous, and leaf characteristics such as length, width, area, perimeter, mass, leaf specific area, and relative water content were significantly correlated (p < 0.05, R > 0.75), with the restored ecosystem during the dry season and the degraded ecosystem during the wet season having greater values. Differences in chlorophyll content were seen in the two types of ecosystems, but not seasonally, with the degraded ecosystem showing the most variation. The results of PCA and regression analysis further verified correlations between leaf morphological characteristics and ecosystem type.