A journey by boat on the country’s largest Kaptai Lake is no longer a fun. Boats carrying tourists on a joy ride get stuck up in the middle of the lake, surrounded by hills. Locals commuting by boats complain of wasting productive hours as the journey gets terribly slow. For all their sufferings they blame an unusual culprit: water hyacinths. The ambience of the man-made lake is under threat as it has been covered with the prolific weeds. Read Landslide warning: People urged to evacuate foothills in Rangamati The unabated growth of the invasive aquatic plants is not only hampering operation of water transports (such as launches, speed boats and engine boats) but also threatening fish and marine resources and polluting its water. According to experts and locals the water of Kaptai Lake has been severely polluted with water hyacinths. Local residents are getting infected with various diseases by using the water of the lake, they said. Visiting the area this week UNB correspondent found a large swathe of the beautiful lake clogged by water hyacinths.