Speaker: Drew Day Presenta0on Date: 12th Jan’12Drew Day is an environmental toxicologist whose focus is on water resource management. He currently works as a core member of Yihua, an environmental networking pla=orm. His earlier research, work, and study in Beijing and Yunnan has led him to develop a high level of Chinese. In January Mr. Day will present a comprehensive view of the sources, implicaEons, and potenEal soluEons to eutrophicaEon, an issue he researched at Dianchi Lake in Kunming. EutrophicaEon is one of the most common environmental issues aﬀecEng China’s waterways, and obstacles to reducing sources and removing nutrient polluEon make soluEons diﬃcult.For any feedback please contact Drew through firstname.lastname@example.org
Presenta0on Overview 1. What is eutrophication, and what are its causes and eﬀects? 2. What is the present eutrophication situation in China? 3. What are the beneﬁts of alleviating eutrophication? 4. What methods are there for restoring eutrophic waters?
What Is Eutrophica0on? Eutrophication is the overenrichment of waters by nutrient input-‐ particularly N and P input -‐ This promotes proliferation of autotrophs, which can lead to algae blooms The plants and algae that bloom cause a surplus of oxygen, which is released into the atmosphere
What Is Eutrophica0on? This oxygen is no longer available to be consumed for decomposing the high number of plants, so the decomposers deplete the remaining oxygen Diﬀerences in salinity or temperature cause stratiﬁcation, which inhibits oxygen replenishment, leading to dead zones
Eﬀects of Eutrophica0on Hypoxia in the hypolimnion Harmful algae blooms Benthic organism mortality Loss of biodiversity Water quality impairment Acid rain (caused by the evaporation of NO2) NO2 High quantities of nitrates can lead to human health problems (over 10 mg/L methemoglobinemia-‐blue baby syndrome)
Causes of Eutrophica0on Fertilizers : Nitrates -‐ volatilization (ammonia): up to 60% of nitrates applied as fertilizer are lost through volatilization (40% is more common) (MA 2005) Surface runoﬀ and leaching into groundwater-‐ on average 20% of fertilizer nitrate lost (MA 2005) Phosphates – soil erosion: binds to the soil Surface runoﬀ and leaching into groundwater -‐ 60% 40% (MA 2005) -‐ 20% (MA 2005) -‐
Causes of Eutrophica0on Manure : More cattle for meat production causes more manure The overuse of manure to fertilize exacerbates runoﬀ issues Meat production in China rose by 127% between 1990 and 2002 (FAO 2009a) As of 2007, fewer than 10% of an estimated 14,000 concentrated animal feeding operations (CAFOs) have installed controls (Ellis 2007) 1990 2002 127% FAO 2009a
Causes of Eutrophica0on Aquaculture : For every ton of ﬁsh, aquaculture operations produce between 42 and 66 kg of N waste and between 7.2 and 10.5 kg of P waste (Strain and Hargrave 2005) 42 66
Causes of Eutrophica0on Urban and industrial : Point source: municipal and industrial discharge via discrete conveyance, such as wastewater treatment plant and industrial wastewater discharges Sewage Non-‐point source: stormwater runoﬀ and nitrogen leaching from septic tanks
Causes of Eutrophica0on Fossil fuels : NOx-‐ smog and acid rain Fossil fuel combustion contributes about 22 teragrams of N pollution globally every year – about 1/5 of the contribution from synthetic N fertilizers (MA 2005) NOx-‐ 22 1/5
Which Is More important?-‐ N or P -‐ Wang, H., & Wang, H. (2009). Mitigation of lake eutrophication: Loosen nitrogen control and focus on phosphorus abatement. Progress in Natural Science, 19(10), 1445-‐1445-‐1451. doi:10.1016/ j.pnsc.2009.03.009 Research in China and North America: multi-‐year comparative research for more than 40 Yangzi River lakes and long-‐term whole-‐lake experiment in N. Am. Indicates P is the key factor in determining phytoplankton growth regardless of N concentrations “To mitigate eutrophication, it is not nitrogen but phosphorus that should be reduced, unless nitrogen concentrations are too high to induce direct toxic impacts on human beings or other organisms.” “
What is the Present Eutrophica0on Situa0on Worldwide? International Lake Environment Committee (ILEC) – “Survey of the State of the World’s Lakes” All 217 lakes covered showed an increase in eutrophication level in the past 50 years Even though by 2000 nutrient inputs to 66 lakes had been reduced, most are still more eutrophied than 50 years ago ILEC -‐“ ” 50 217 2000 66 50
What is the Present Eutrophica0on Situa0on Worldwide? -‐1 -‐1-‐2 -‐1 -‐1 -‐2
What is the present eutrophica0on situa0on in China? In a 2003 survey of 50 major Chinese lakes, 66% have eutrophic or hypereutrophic conditions The 5 largest freshwater lakes are all eutrophic or hypereutrophic Urban lakes are nearly all in a hypereutrophic state 2003 50 66% 5
What is the present eutrophica0on situa0on in China?
What is the present eutrophica0on situa0on in China?
Dianchi Lake 400 300 200 100 0 1990 1992 1994 1996 1998 2000 2002 Agricultural produc0on value per unit produc0on area (ten thousand yuan/ha.) Applica0on of Nitrogen fer0lizers per unit area (tons/1000ha) Applica0on of phosphate fer0lizers per unit area (tons/1000ha) Applica0on of pes0cide per unit area (tons/1000ha)
What are the beneﬁts of allevia0ng eutrophica0on? Improving the quality of water used for all purposes Increased aesthetic and recreational value of adjacent land The restoration of species important to local food chains, thus bolstering the local ﬁsh industry A reduction of the amount of money, capacity, and maintenance needed for water treatment A reduced health threat to the local population
A business case for eutrophica0on mi0ga0on Economic eﬀects of eutrophication and beneﬁts of reducing eutrophication (UNEP. Planning and Management of Lakes and Reservoirs: An Integrated Approach to Eutrophication. 2000) Eﬀect of Eutrophication Beneﬁts of Reducing Eutrophication •Lower costs of treating water Increased taste and odour •Happier consumers problems in water supply •Less need for substitute water (e.g., bottled water) •Increased consumption of water and diﬀerential between prices of substitutes and municipal supply •Happier nearby residents Reduced visual and tactile •Increased development around water body qualities of water body •Increased recreation •More diverse biota •Increased value of properties •Increased commercial and recreational ﬁshing Increased possibility of toxins •Increased development of land •More diverse biota in water •Increased expenditures on recreation •Prices for water contact •Increased diﬀerent ﬁsh caught •Increased number and value cosystem •Public’s WTP for improved e of ﬁsh caught •Public WTP for improved ecosystem •Reduced nexpenditures on recreation •Increased eed for alternative water supplies Loss of water depth, surface •Values of shoreline property preserved area, and storage capacity •Continued viability of ﬁsheries •Continued viability of recreation •Avoided costs for dredging and substitute water supplies
What methods are there for restoring eutrophic waters? Water treatment coupled with nutrient removal Water treatment plants Pumping stations to remove algae Lake and riverbed dredging
What methods are there for restoring eutrophic waters? The addition of chemicals to prevent nutrient or algae increases Hypolimnetic aeration: prevents nutrient upwelling and increases oxygen in the hypolimnion Addition of gases to kill algae – ozone (expensive) –
What methods are there for restoring eutrophic waters? Methods for restoration of lakes and reservoirs (UNEP. Planning and Management of Lakes and Reservoirs: An Integrated Approach to Eutrophication. 2000) Method Application Costs In situ precipitation often not applicable to shallow lakes low Removal of sediment limited to shallow lakes very high not recommended Algicides medium Coverage of sediment general medium-‐high -‐ has only long-‐term eﬀects for small lakes Shading by trees very low removal of nutrients from inﬂow water Wetlands medium only applicable to lakes with thermocline Aeration high to very high -‐ only applicable to lakes with thermocline medium, high if P-‐ removal is required Siphoning Biomanipulation only in the P-‐range 0.05-‐0.15 mg/l usually low 0.05-‐0.15 / the problem is moved not solved Diversion case dependent
What methods are there for restoring eutrophic waters? Public education and assistance Environmental education Public Awareness Technical assistance
What methods are there for restoring eutrophic waters? Regulations Standards Product/manufacturing – e.g., controlling the amount of phosphates in detergents and fertilizers Process/design – e.g., Maryland’s Stormwater Management Act of 2007 (reducing nutrient runoﬀ) Technology/practice – e.g., enhanced nutrient removal technology for treatment plants (capable of reducing N concentrations in wastewater to 3 mg/L and P concentrations to 0.3 mg/L) Eﬄuent/emission caps – e.g., capping the amount of N and P leaving a watershed (as in the U.S. Clean Water Act) / – / – 2007 / – 3 / 0.3 / / –
What methods are there for restoring eutrophic waters? Fiscal and Economic Incentives Ecotaxes Polluter-‐pays tax – e.g., Denmark’s wastewater tax (tax point-‐sources for every unit of N, P, and BOD discharged) and Netherlands nutrient budget fee system Dedicated environmental tax – e.g., Maryland “ﬂush tax” (tax on water and sewer bill, used to add to nutrient removal technology in treatment plants) Technologies/products/inputs taxes – e.g., fertilizer tax “ ” – – “ ” / / –
What methods are there for restoring eutrophic waters? Incentives and subsidies Incentive payments, subsidies, low-‐interest loan programs, and tax credits E.g., agricultural preservation subsidies – encourage best management practices E.g., Pennsylvania Resource Enhancement and Protection Program – tax credit for farmers using best management practices to improve water quality (estimated from 2007-‐08 N pollution reduced by 162,176 lbs and P pollution by 14,939 lbs) E.g., U.S. Clean Water State Revolving Fund -‐ $5 billion per year in low-‐interest loans to fund water quality protection projects Performance-‐based approaches – e.g., reverse auctions – – 2007 2008 162,176 14,939 – 50 –
What methods are there for restoring eutrophic waters? Ecolabeling – encourage ‘green’ products Environmental Markets – provide price signals for environmental goods Regulatory markets – provide ﬂexibility and reduce the ﬁnancial burden of regulatory compliance E.g., Long Island Sound Nitrogen Credit Exchange in Connecticut – lets plants meet N discharge limits by upgrading their facilities or by purchasing N oﬀsets from plants operating below their discharge limit – ‘ ’ – – –
What methods are there for restoring eutrophic waters? Voluntary markets – driven by value placed on env. good or service by buyers E.g., Chesapeake Fund – voluntary nutrient market created by a consortium of NGOs – –
What methods are there for restoring eutrophic waters? Restoration and Protection of Ecosystems Protected areas E.g., The Danube Delta under the UNESCO Man and Biosphere Program Land purchases and conservation easement establishment E.g., Worcester Land Protection Partnership: a partnership between the city of Worcester and the Trust for Public Land in which they identify and acquire priority watershed land Habitat restoration E.g., submerged aquatic vegetation and oyster bed restoration in the Chesapeake Bay
What methods are there for restoring eutrophic waters? Restoring ﬂood pulse and hydrological extremes Cyanobacterial blooms in a temperate river-‐ﬂoodplain ecosystem: The importance of hydrological extremes. (2011). Aquatic Ecology, 45(3), 335-‐335-‐349.