By Nudge Sustainability Reporter Trish Nyarumbu
Rivers, dams and lakes play a very important role in the ecosystem as sources of water for all forms of life, habitat and also of aesthetic value to nature. Their importance seems to be undermined assuming the rate at which eutrophication is taking place especially in the urban areas of many cities in Zimbabwe.
It has favored the growth and proliferation of water hyacinth (Eichhornia Crassipes Martius) which is considered as noxious weed in a number of countries. Water hyacinth depletes oxygen rapidly thus is affecting all forms of aquatic life. The increase in hyacinth populations is a clear indication that the water systems are heavily enriched with nitrogen and phosphorous nutrients.
The contribution of agriculture to this matter can not be undermined as it is one of the major activities taking place along river banks and in wetlands (Figure 1) resulting in an increased nutrient load in rivers through leaching of fertilizers and soil erosion.
The construction of residential stands (Figure 2), factories and pavements also destroy the soil affecting the natural mechanism of self purification of wetland areas.
The colonization of water bodies with such water weeds (Figure 3) becomes a challenge for the water system because it leads to poor water quality, obstruction of recreation and loss of aquatic biodiversity.
Whose responsibility is it then?
Communities should be made aware of the need of sustainable utilization of environmental resources and the consequences of environmental degradation. That sense of belonging should be instilled through participatory programs from grassroots level. There are local initiatives in environmental conservation such as Mukuvisi Woodlands which are open to tours from youngsters to older people.