The Maldharis, inhabitants of western India, have been using mangroves as a traditional means of livelihood, including the rearing of Kharai camels, whose main food source is mangrove leaves. To obtain basic information on the ecosystem services of the mangrove forests they use, we are using satellite remote sensing data to develop a quantitative description of mangrove biomass since the 1980s. We used Landsat multispectral imagery to study the long-term variability of NDVI in several target grazing forests. The overall NDVI of mangrove forests in the region has increased from 1988 to the present, and the cover has not decreased, suggesting an increase in biomass. This suggested that local pastoralists harvested the leaves and branches of the mangrove forests as a resource, but did not destructively take the trees from the forests. However, it has been decreasing in the late 1990s and early 2000s. The most likely reason for this is the increase in water stress due to the continuous low precipitation (drought) in the late 1990s and early 2000s. On the contrary, the lack of significant changes in NDVI due to a single year of drought suggests that the mangrove forests in this region are drought tolerant.