Envisioning Ecosystem Services Scheme for Lake Tana, Ethiopia
Lake Tana is known for its unique ancient cultural heritage and biodiversity. Within the lake’s periphery, there are about thirty-seven islands––twenty of which host Ethiopian Orthodox churches containing different plant and animal species that have local and international significance. It also provides different ecosystem services that have significant ecological value and support livelihood to millions of people. However, external pressures like land degradation, erosion, and the eutrophication of the lake have resulted considerable negative effects on the flora and fauna of the lake resources.
Beyond other anthropogenic factors, recently the lake is under pressure from an invasive species––water hyacinth (Eichhornia crassipes). Since 2011, the water hyacinth (Eichhornia crassipes) has invaded Lake Tana, causing significant damage on the biodiversity and provisions of the lake. The exact cause and source of the water hyacinth infestation are not clearly known, but are probably favored by factors such as sedimentation, extensive fertilizer application in the agricultural parts of the catchment, and pollutants (nutrients) from the surrounding cities (mainly Bahir Dar and Gondar). Its coverage has escalated from 20 ha in 2012 to more than 50,000 ha in 2014. The weed grows rapidly and produces enormous amounts of biomass, thereby covering extensive areas of naturally open water. Displacement of water by water hyacinth is another threat that has reduced the capacity of water reservoirs. It can also have a severe effect on water transport. Fishing in lake Tana is also becoming increasingly time consuming, while physical interference with nets makes fishing more difficult or impractical.
So far, different efforts have been made to contain the spread of the water hyacinth. Previous efforts have focused on removing the weed, either manually or using machines to reduce coverage and to slow down its spread. So far, the local authorities have mobilized an estimated number of 162,000 people to remove the weed by hand. This effort is limited to areas which are accessible to clear the weed in the offshore land mass. There is also an established institutional arrangement to protect and manage lakes in Amhara region, Ethiopia. However, the water hyacinth weed has remained a serious threat and risking the habitat, and biodiversity surrounding Lake Tana. As a result, efforts are being made by different actors to find an alternative, timely, and prudent management options. A new management system like payment for ecosystems services (PES) can save Lake Tana.
Ecosystem services are the many and varied benefits to humans gifted by the natural environment and from healthy ecosystems. Human interference and non-optimal use of resources have led to the degradation of many provisions derived from ecosystems. Tropical rainforests disappear due to illegal logging and extensive slash and-burn practices, river basins are polluted by agrochemicals, and mountain watersheds are degraded by non-sustainable management practices. The case of Lake Tana is not different from this phenomenon. Population pressure and expansion of agricultural practices, and the accompanied economic demand coupled with the Hyacinth weed put Lake Tana under a serious threat.
Recently GIZ, in a feasibility study commissioned by UNESCO, documented the biosphere potential of Lake Tana. Based on FAO classification of ecosystem services and functions, some of the ecosystem services that are derived from Lake Tana include: regulatory function (carbon sequestration and sinks, water supply, and habitat for biodiversity), support agricultural production, and cultural and aesthetic values.
The regulatory functions of Lake Tana are vast and crucial for the population living and dependent upon the healthy functioning of the ecosystem. The regulatory role includes water/hydrological regulation, carbon sink/climate regulation, control of winds and extreme weather events, and regulating the biodiversity. It also regulates hydrological flows and provides us an optimization of extremes in discharge of rivers, maintain of natural drainage and irrigation, and regulation of channel flow beneath to the Lake. Water supply refers to the retention, filtering and storage of water in lakes, streams and aquifers. Lake Tana provides the highest water regulatory functions. It can also regulate the climate by storing greenhouse gases. Water bodies, like trees and plants, can sink carbon and contribute to the carbon sink/climate regulation objective.
Habitat for species, and maintenance for genetic biodiversity, are the nature supporting services of ecosystems. Ecosystems create a suit of environment that is suitable for plant and animals’ reproduction. It also maintains the different genetic resources for a better understanding and discovery of genetic pools for a commercial purpose. Lake Tana is supporting the aquatic animals, birds, and the surrounding offshore inhabitants. It is the home of many (300) birds, fish, and many other aquatic mammals. Recently there are an estimated number of 5,400 fishers in the lake. However, the size and quality of fishing is getting worse mainly because of non-optimal harvest and lack of proper fishing technology.
Cultural and recreational services
Lake Tana is one of the sacred places in Ethiopian Christianity. Around Lake Tana and on 20 of its 37 islands, churches have guarded cultural treasures for many centuries. Culture and nature based attractions plays an important role in the healthy functions of our mind. The recreational values of nature are enormous. People love to visit water shores, hike mountains, boating on lakes and rivers, walking on green areas, and visiting sacred and tourism destine places. Lake Tana has such a prestigious world heritage sites, and attractions within the islands of the Lake attracting millions of local and international tourists every year.
Despite having all these ecosystem services, Lake Tana is being challenged by both human induced and natural uncertainties. Some people preferred to call the current eminent threat posed by the invasive water hyacinth, as “Tana is crying.” Human induced, and other activities which are not environmental friendly, lack of prudent and committed leadership, and the public goods nature of Lake Tana has made interventions challenging.
Towards Payment for Ecosystem Services (PES) for Lake Tana
Payment for ecosystem services (PES) schemes have an objective of changing the behaviors of humans that have led to the degradation of the most valuable ecosystems. PES can help us address market failures, and have proved to show an interesting outcome in environmental conservation and management, especially for ‘public goods’. We propose a PES schemes for Lake Tana in the face of the invasive water hyacinth, and an imminent natural resources degradation in the surrounding environment.
Ostrom have provided us an alternative common pool natural resources management in the presence of market failure and asymmetric information. Ostrom’s cooperative local institutions have showed evidence in avoiding the tragedy of the commons without requiring top-down regulation, with certain conditions need to meet. By localizing Ostrom’s cooperative local institutions into the management and use of ecosystem services of Lake Tana, we propose to establish a distinguished ecosystem service users group, and a cooperative local institutions under PES schemes. In the literature, there are two proposed PES financing options; government/NGOs financing, and user financing options. For Lake Tana, it is possible to consider both financing options. A summary of the different PES schemes implemented in different countries can be found in UNEP.
Table 1. Proposed PES scheme for Lake Tana
The cooperative local institutions, like any other cooperatives in the country can be arranged either by market forces or local government. The cooperative local institutions or individual and communal land owners can be organized as a for profit organization with an objective of maintaining and sustaining the Lake from threats arise from both anthropogenic and natural environmental changes. In turn, the cooperative local institution collect ecosystem service fee from ecosystem beneficiaries. The government, in consultation with researchers, should design a payment vehicle and value for the different ecosystem services. Using environmental valuation methods, economic value of the different ecosystem services can be determined and user fees can then be attached. Appropriation and payment system will then be enforced through the market mechanism, and through annexing the system into local policy and law.
In conclusion, PES in a localized cooperative institutions framework is possible through active government role. First, conducting an environmental valuation of the different ecosystem services of the lake is necessary in order to determine the value and appropriate payment system. Once, the supply side is arranged, supported by appropriate polices and legal frameworks, the government or other concerned bodies can create an enabling environment to establish local cooperative institution, and/or organize communal and individual farmers to manage and conserve the lake’s ecosystem and habitat. This process creates a working market to manage and sustainably use Lake Tana’s ecosystem services.