Water Quality and Trophic State of the Tourism and Agricultural Zone in Lake Yojoa

Abstract

Eutrophication, caused by excess nutrients such as phosphorus and nitrogen, alters the physical, chemical, and biological characteristics of water, negatively affecting biodiversity. This phenomenon, exacerbated by human activities such as agriculture and tourism, poses a growing threat to Lake Yojoa, the only significant freshwater body in Honduras. Population growth and human practices have raised nutrient levels, deteriorating water quality. This study evaluated the state of the lake using the Water Quality Index of the Canadian Council of Ministers of the Environment (WQI-CCME) and other trophic indices. Two analysis zones were established: Zone A, related to tourism, and Zone B, linked to agriculture. During 2023, quarterly sampling was carried out and eight physicochemical parameters were analyzed, such as pH, dissolved oxygen (DO), and total nitrogen (TN). The results showed “poor” quality in Zone A (WQI of 44) and “marginal” quality in Zone B (WQI of 45). According to the Carlson index, both zones were classified as eutrophic, indicating a high presence of nutrients and algae proliferation, confirmed by the attenuation coefficient (K). The T-test revealed significant differences in TN, with higher concentrations in Zone A, suggesting that tourism has a more negative influence than agriculture on the eutrophication of the lake.