Eutrophication

Urban Wastewater Treatment and Marine Outfall Facilities are being planned in accordance with Istanbul Water Supply and Wastewater Treatment and Disposal Master Plan prepared for Istanbul Water and Sewerage Administration (ISKI) in 1999. According to the Master Plan, ISKI initiated in 1996 the water quality monitoring program of receiving water bodies conducted by the Istanbul University (IU) Institute of Marine Sciences and Management and Istanbul Technical University (ITU) Environmental Engineering Department. The monitoring program has been carried out for 10 years in 28 stations in the marine environment. In this paper, the results of experimental investigations conducted for parameters including dissolved oxygen, total organic carbon (TOC), particulate organic carbon (POC), Total-N, Total-P, chlorophyll a, structure of benthic community, turbidity and coliforms have been critically analysed taking into consideration the marine outfall and surface water discharges from Istanbul's major wastewater treatment plants together with the transboundary pollution sourced by the Black Sea. The studies reveal that the water quality in the Marmara Sea is deteriorated more than anticipated before, and it is a necessity to develop international cooperation aimed for taking more effective measures in the area.

Elevated concentrations of arsenic (As) occurred during warm months in water from the outlet of Lake Mohawk in northwestern New Jersey. The shallow manmade lake is surrounded by residential development and used for recreation. Eutrophic conditions are addressed by alum and copper sulfate applications and aerators operating in the summer. In September 2005, arsenite was dominant in hypoxic to anoxic bottom water. Filterable As concentrations were about 1.6-2 times higher than those in the upper water column (23-25 lg/L, mostly arsenate). Hypoxic/anoxic and near-neutral bottom conditions formed during the summer, but became more oxic and alkaline as winter approached. Acid-leachable As concentrations in lakebed sediments ranged up to 694 mg/kg in highly organic material from the tops of sediment cores but were \15 mg/kg in geologic substrate. During warm months, reduced As from the sediment diffuses into the water column and is oxidized; mixing by aerators, wind, and boat traffic spreads arsenate and metals, some in particulate form, throughout the water column. Similar levels of As in sediments of lakes treated with arsenic pesticides indicate that most of the As in Lake Mohawk probably derives from past use of arsenical pesticides, although records of applications are lacking. The annual loss of As at the lake outlet is only about 0.01% of the As calculated to be in the sediments, indicating that elevated levels of As in the lake will persist for decades.

Using radium (Ra) isotopes and nutrient analyses, we found that submarine groundwater discharge (SGD) is an important source of ''new'' nutrients, particularly nitrogen, to coral reefs around the world. Nitrogen input estimates associated with SGD range from 3 to 800 mmol h Ϫ1 per meter of shoreline. The use of Ra isotopes allows us to quantify the inorganic nitrogen input from this source of nutrients. Increasing coastal population and land use practices may enhance anthropogenic nutrient loading from submarine groundwater contributing to reef degradation.

Climate change may have profound eff ects on phosphorus (P) transport in streams and on lake eutrophication. Phosphorus loading from land to streams is expected to increase in northern temperate coastal regions due to higher winter rainfall and to a decline in warm temperate and arid climates. Model results suggest a 3.3 to 16.5% increase within the next 100 yr in the P loading of Danish streams depending on soil type and region. In lakes, higher eutrophication can be expected, reinforced by temperature-mediated higher P release from the sediment. Furthermore, a shift in fi sh community structure toward small and abundant plankti-benthivorous fi sh enhances predator control of zooplankton, resulting in higher phytoplankton biomass. Data from Danish lakes indicate increased chlorophyll a and phytoplankton biomass, higher dominance of dinophytes and cyanobacteria (most notably of nitrogen fi xing forms), but lower abundance of diatoms and chrysophytes, reduced size of copepods and cladocerans, and a tendency to reduced zooplankton biomass and zooplankton:phytoplankton biomass ratio when lakes warm. Higher P concentrations are also seen in warm arid lakes despite reduced external loading due to increased evapotranspiration and reduced infl ow. Th erefore, the critical loading for good ecological state in lakes has to be lowered in a future warmer climate. Th is calls for adaptation measures, which in the northern temperate zone should include improved P cycling in agriculture, reduced loading from point sources, and (re)-establishment of wetlands and riparian buff er zones. In the arid Southern Europe, restrictions on human use of water are also needed, not least on irrigation.

h i g h l i g h t s < We provide an approach to estimate regional fate factors at a global scale. < Transboundary impacts can now be evaluated in life cycle impact assessment (LCIA). < We favorably compared the approach results with direct GEOS-Chem outputs. < The uncertainties and limitations of the approach are acceptable for LCIA purposes.

Soybean production and its supply chain are highly dependent on inputs such as land, fertilizer, fuel, machines, pesticides and electricity. The expansion of this crop in Brazil in recent decades has generated concerns about its environmental impacts. To assess these impacts, two representative chains supplying soybeans to Europe were identified: Center West (CW) and Southern (SO) Brazil. Each supply chain was analyzed using Life Cycle Assessment methodology. We considered different levels of use of chemical and organic fertilizers, pesticides and machinery, different distances for transportation of inputs and different yield levels. Because transportation contributed strongly to environmental impacts, a detailed study was performed to identify the routes used to transport soybeans to seaports. Additionally, we considered different levels of land occupation and land transformation to represent the impact of deforestation in the CW region. Environmental impacts were calculated for 1000 kg of soybean up to and including the delivery to Europe at the seaport in Rotterdam, at 13% humidity. Overall results showed that the impacts are greater for CW than for SO for all impact categories studied, including acidification (7.7 and 5.3 kg SO 2 eq., respectively), climate change (959 and 510 kg CO 2 eq.), cumulative energy demand (12,634 and 6,999 MJ) and terrestrial ecotoxicity (4.9 and 3.1 kg 1,4-DCB eq.), except eutrophication and land occupation. The same trend was observed for the crop-production stage. Efforts to reduce chemical fertilizers and diesel consumption can reduce CO 2 emissions. Although deforestation for crop production has decreased in recent years, the contribution of deforestation to climate change and cumulative energy demand remains significant. In the CW scenario deforestation contributed 29% to climate change and 20% to cumulative energy demand. Results also showed that although there are different transportation options in Brazil, the current predominance of road transport causes severe environmental impacts. In CW, road transport contributed 19% to climate change and 24% to cumulative energy demand, while in SO it contributed 12% and 15% to these impacts, respectively. Improvements in the logistics of transportation, giving priority to rail and river transports over road transport, can contribute significantly to reducing greenhouse gas emissions and decreasing energy use. Future studies involving Brazilian soybeans should take into account the region of origin as different levels of environmental impact are predicted.

The effect of continental inputs on environmental conditions and chlorophyll-a have been studied monthly in surface water samples from 5 littoral stations in central Lebanese coastal waters for a period of 3 years between September 2009 and June 2012. Three stations show different levels of impact as a result of river inputs and sewage discharges. The other 2 stations were taken as references.
During the study period, temperature followed its normal annual cycle whereas salinity varied spatially and temporarily sometimes with low values due to the continental inputs (range = 1.3 - 39.65). Significant nutrient fluctuations were also recorded (range N-NO3= 0.34-40.8 μmole/L; range P-PO4= 0.11-5.8 μmole/L). High levels of nitrate were observed at stations located near rivers and sewage discharge points while high levels of orthophosphate were detected in the stations affected by sewage waters. These inputs however, cause an increase in primary productivity as evidenced by chlorophyll-a levels; therefore, chl-a concentrations (range= 0.01- 8.9 mg/m3) throughout the study period showed high values in the stations affected both by sewage and river inputs comparing to the reference stations; this result could lead to a dystrophic situation.
The outcome of the one way analysis of variance (ANOVA) for the whole period showed significant differences within the stations for all the considered environmental variables except temperature. The results were different when the analysis was done within seasons. The intermittent discharge of river and sewage effluents and the deteriorated conditions observed near the shoreline created a clear difference in the levels of the studied parameters. According to the results and comparing to the reference values of Lebanese coastal waters, the area of Antelias River shows signs of eutrophication as a direct result of river and sewage inputs.