Freshwater ecosystems are a division of the aquatic systems of the earth and include ponds, streams, rivers, wetlands, lakes, and springs. Freshwater habitats are classified on different factors including light penetration and vegetation. Freshwater can be divided into lotic (if flowing) or lentic (if still) ecosystems. The study about freshwater ecosystem is known as limnology. There have been efforts to help monitor and understand freshwater ecosystem due to threats to human health like cholera outbreaks. This paper will discuss the freshwater ecosystem, how it has been impacted by agriculture, and the effect of a growing population on such an ecosystem. The paper will further discuss a management practice for sustainability and conservation of natural resources in a freshwater ecosystem, risks and benefits associated with use of energy from such an ecosystem and management practices for sustainability and conservation of natural resources.
Agricultural Impacts on Freshwater Ecosystems
Threat to Freshwater Ecosystems
The major threat today to freshwater systems is agricultural activities as carried out by human beings. Agricultural activities involve raising of livestock and crops for food. Of course we have to farm to support our lives but unfortunately this vital activity hurts the earth’s freshwater systems. Agriculture accounts for about 70% of our freshwater use and although freshwater is a renewable resource, it is not unlimited. Crops like cotton, sugar, and rice need a lot of water to grow. For example it can take a whooping 5,000 liters of water to grow just 1kg of rice. To put this into perspective, in 2008 alone, USDA forecast for world rice production was 394 metric tones (Ronca, n.d.).
Water may be indispensible for farming but some countries grow crops that are not suitable for the local soil or climate and when overproduction occurs, the soil salinity increases making it difficult to grow crops anymore. In turn farmers start using pesticides and chemicals to grow their crops. The chemicals are washed down into freshwater sources and destroy the freshwater habitats and species that live there. Another threat to freshwater ecosystems is as a result of construction of dams used for irrigation. Dams are used to divert water flow systems which affect the habitats of local fish and other freshwater animals, reduce spawning, threaten species, and increases flood risk. The poor irrigation and drainage in agriculture also results to squandering of precious water (Ronca, n.d.).
Effects of a Growing Human Population on Freshwater Ecosystem’s Resources
In a world where nearly all the natural ecosystems are under stress, freshwater ecosystems are the most endangered of all. Species especially from freshwater ecosystems are more threatened with extinction, according to the World Conservation Union. In the last few decades, freshwater ecosystems have lost a greater proportion of their species than any other ecosystem mainly because they are in greater danger from pollution, irrigation, overfishing and other threats as a result of overpopulation. Overpopulation of human beings is the biggest threat the freshwater ecosystem.
The majority of the world population lives near freshwater environments and with most inland cities located adjacent to freshwater bodies like rivers or lakes. As the population of the people increases, there is also an increased appetite for freshwater supplies including overfishing, increased construction of irrigation projects and dams to cater for increased demand of food. Building of dams and channelization are some of the most pervasive threats to freshwater bodies today as a result of the growing population. For example, on the Rhine River, after decades of channelization and other developments on the river, the native salmon fish species has run out while the original flood plains are no more. The extent and scale of these human impacts have been rising due to an increasing population in the recent years. An example is the number of channelization of more than 500,000 from less than 9,000 in 1900 (The decline of freshwater ecosystems, n.d.).
According to a report by Ricciardi and Rasmussen (1999), since 1900, a total of 123 freshwater species have been reported to be extinct in North America alone. Hundreds of other species including fishes, amphibians, crayfish, and mollusks are seen as endangered species. The two authors made use of an exponential decay model and arrived at recent and even future extinction rates for North America’s freshwater species. This model unfortunately predicts a 4% extinction rate per each decade. This suggests that the North America temperate freshwater ecosystem is being depleted of its species very rapidly. These alarming trends for freshwater species have been linked to extensive destruction of our habitat by poor land use methods as a result of the ever growing human population. This has resulted to organic pollution from land use activities, toxic contaminants from factories, flow regulation, interaction with some exotic species, and land-use activities. This growing population has exerted unnecessary pressure to freshwater and the human activities have now led to deterioration of the world’s freshwater ecosystem (Ricciardi and Rasmussen, 1999).
In South America for example, The Water Highway Project will result in a 3,400 shipping corridor in a bid to open up landlocked Bolivia and Paraguay as well as parts of Brazil to trade. The project involved widening, dredging, and straightening sections of Paraná and Paraguay rivers passing through Gran Pantanal which is one of the largest wetlands in the world. Unfortunately, the rivers will endanger some 650 varieties of birds, 600 fish species, 80 different types of mammals and another 90,000 varieties of plants (The decline of freshwater ecosystems, n.d.).
Discuss one management practice for sustainability and conservation of natural resources in that ecosystem
The demand for water has been increasing since the population has been growing at an alarming rate leading to fresh water becoming a scarce resource. This has also been contributed by longer periods of drought experienced in the recent times as well as changing climate patterns. Direct regulations are management practices that have been used widely throughout the world to conserve fresh water biodiversity. It involves protection of fresh water areas, legislation that will stop or reduce unnecessary developments of freshwater resources, establishing policies against hunting and provision of incentives and subsidies which will encourage efficient use of water.
Use of direct regulations is an efficient management practices because the regulations are not flexible and hence no manipulation on the fresh water ecosystem since failure to abide by them will attract a high cost on the individual, community or government. They can only be useful if they are well designed, managed and administered. For instance, un-metered water supplies in urban areas a, flat rate of electricity that is consumed in the pumping water and water pricing structures build in the irrigated areas in Balochistan. However, the government’s effort to use legislation measures in curbing the situation has failed due to highly influential social-political forces which pull back these efforts.
In Mexico, the state exercises it authority to regulate the construction of new wells and also the volume of water extracted from the existing wells. Legislation to prevent over-exploitation in Mexico has for over 50 years failed. Due to failed national legislations, it has been suggested that economic measures should be established to complement them as well as those of International Water Management Institute (IWMI) which have equally failed.
In addition to water conservation, biodiversity goods and services requires great control and regulation. This can be done by the governments ensuring efficiency in the provision by markets of goods and services which are non- excludable biodiversity. Mostly used instruments which are better alternatives to direct regulations on improving environmental quality are market-based instruments (MBI) which many countries are now increasingly using. The creation of markets for natural resources, it is possible to communicate the message that there is true scarcity of resources and thus create an economic incentive for wiser management of natural resources The Conservation and Sustainable Use of (Freshwater Resources, n.d.).
Risks and benefits of extracting or using one type of nonrenewable and one type of renewable energy resource from freshwater ecosystem, or in areas near the ecosystem
Crude oil is a non-renewable energy carrier from which oil products are manufactured from. It is a risk process since during the drilling process from underground reservoirs; the oil may spill either during pumping it out and may be washed by rain water into the freshwater ecosystem where it insulates the surface of the water against entry of oxygen. This leads to the suffocation of aquatic animals and hence dying. The layer of oil may also interfere with the amount of light reaching the water affecting the process of photosynthesis by the phytoplankton. A lot of water, approximately 2-8 m^3 of water per 10^3GJ (thermal) is normally required for the drilling process and hence depriving the aquatic life of water and hence they may die son. The benefits of mining crude oil near the freshwater source are that it is a raw material for many oil products such as kerosene, petrol and gasoline.
Electricity from hydropower is a renewable energy which is produced as a result of potential energy of water to drive turbines and hence generating energy. It is a risk process since many aquatic animals that might have found a niche in the dam are killed when the water is released to the turbines. Those that remain may lack the right quality and quantity of water to survive well. The water stored for this purpose may be rechanneled water from a nearby fresh water source and hence less water is going to be available for so many organisms in its ecosystem. The benefit is that it provides a temporary ecosystem for survival and the interaction of various organisms (Van der Meer, n.d.).
Management practices for sustainability and conservation of natural resources and energy
Water is one of the natural resources that need to be conserved for it to be sustainable. In Piedmont city, for instance, the Alameda County Storm water Quality Management Plan has been implemented. It involves planning and regulatory compliance, illicit discharge controls, monitoring and special studies, industrial and commercial discharge controls and public information and participation. The city recommended the establishment of “Best Management Practices” which will help in the reduction of pollution caused by storm water. This help safe guard the biodiversity in the ecosystem.
“ Green buildings’’ is a sustainable management practice which incorporates water conservation systems which are buildings designed to suit the natural resource being conserved and its impact on the environment. The structure uses motion-activated light switches to save energy. In an effort to minimize the drilling and mining different forms of energy, solar energy can be trapped in solar panels to be used where applications are of a smaller scale such as domestic water heating. In conservation of water “bay friendly’’ landscape guidelines helps to decrease the amount of water used and promotes planting of native trees such as woodland that support other forms of life like the birds and other wild life. There should be a proper local plan that will protect the habitats of endangered species and other species which may be of special concern to the public (5 Natural Resources and Sustainability, n.d.).