Using multiple satellite observations to quantitatively assess and model oil pollution and predict risks and consequences to shoreline from oil platforms in the Caspian Sea

This research focused on the following objectives: (1) using satellite data to characterize the spatiotemporal distribution of anthropogenic oil spills from Oil Rocks Settlement, Chilov and Pirallahi Islands (2) stochastic modeling of the oil spill risk pose to water quality and shoreline ecosystems, and (3) validating model predictions using satellite images. 165 satellite images acquired by SENTINEL-1A, LANDSAT-8, RADARSAT, ENVISAT and ERS sensors between 1996 and 2015 were used for the detection of oil spills using object-based classification and visual interpretation. Anthropogenic hotspots were observed at three oldest oil production sites with estimated oil spilling up to 1264 m³ per day and different degrees of temporal repetition of oil spills. The largest area (5639 km²) experienced 1–10 detected oil spills, while 993 km² experienced 11–20 oil spills, 775 km² experienced 21–50 oil spills, 208 km² experienced 51–100 oil spills, and 36 km² experienced 101–150 oil spills. The majority (83% or 6157 km²) of sea surface area within the combined boundary of detected oil spills (7422 km²) had a 50% or greater chance of oil spill contamination. Approximately, 6% (44 km of 751 km) of shoreline had a 50% or greater probability of contamination with land use classes sensitive to pollution.     

The boundary filtration effect of reed-dominated ecotones under water level fluctuations

The boundary filtration effect of land/water ecotones with reed-bed/ditch systems under water level fluctuations was studied in Baiyangdian Lake of North China. It was found that the changes in reed bed areas which were primarily affected by water level fluctuations and the root channels in the wetland soils together largely determined boundary filtration efficiency. The ecotones displayed the greatest boundary effect at a moderate water level of about 8 m above sea level. The massive root channels in the wetland soils promoted water flowing into the reed beds as far as 8 m horizontally by subsurface in wet years. In dry years, when the water level was below the root channel distribution zone, the lateral water exchange width of ecotones was limited to 0.5 m along the fringe area. It is calculated that, at 8 m water level, the total boundary length of ecotones is 7,273 km and the boundary exchange volume is 5.8 × 10⁶ m³. While at 6.5 m water level, the total boundary length of ecotones is reduced to 2,699 km and the boundary exchange volume is 1.1 × 10⁵ m³. The standard capacity for phosphorus retention was 105.9 and 2.5 tonnes at water levels of 8 and 6.5 m, respectively. This suggests that the boundary filtration effect of reed-bed/ditch wetlands is important for improving the water quality of inland waters, and this effect should be considered in regulating and managing lake water levels.     

Interim Hydrologic Responses to Phase I of the Kissimmee River Restoration Project,Florida

Hydrologic conditions were evaluated during a 10‐year Interim Period following completion of Phase I of the Kissimmee River Restoration Project and initiation of environmental water releases from upstream to provide adaptive management of flow to the Phase I area. Phase I construction backfilled 13 km of flood control canal C‐38 and redirected flow into 22 km of reconnected river channel. Evaluations focused on five restoration expectations (performance measures) based on pre‐channelization hydrologic data for the Kissimmee River. Environmental releases resulted in more continuous discharge from upstream, but did not affect the magnitude of discharge. After backfilling of C‐38, water levels in the Phase I area varied with discharge and periodically inundated the floodplain. However, the long, annual recession event, characteristic of pre‐channelization, was not reestablished; instead, most Interim Period years had multiple events with shorter durations and faster recession rates. Mean channel water velocity increased during the Interim Period but was not always in the desired range. Hydrologic conditions throughout much of the Phase I area were affected by the backwater effect of the downstream water control structure. Four expectations showed improvements in terms of number of years met; however, none met the expectation targets. The inability to meet expectation targets reflects in part the incomplete or interim status of the restoration project.     

ATOC AND OTHER FACTORS AFFECTING THE DISTRIBUTION AND ABUNDANCE OF HUMPBACK WHALES (MEGAPTERA NOVAEANGLIAE) OFF THE NORTH SHORE OF KAUAI

Humpback whale diving behavior changes subtly when exposed to signals transmitted from the Acoustic Thermometry of Ocean Climate (ATOC) sound projector located 14 km offshore the island of Kauai. This study considered whether such responses would lead to changes in distribution and abundance. A land-based shore station measured humpback whale locations (scan samples) for both nearshore (<5 km) and offshore (5–10 km) areas. Control observations were made in 1994 and 1998. In 1998 multipleday blocks with ATOC transmissions were interspersed with multiple-day control blocks without transmissions. Sighting rates were higher in 1998 (ATOC) than in 1994 (control year), probably due to better sighting conditions, but may reflect increased population size. Sighting rates did not differ between control and ATOC conditions in 1998. A seasonal sighting peak was observed in both years. No vessel effect on sighting rate was detected in 1998.
There was no effect of ATOC on the distance from the shore station to whales, or the depth of water where pods were located. However, the distribution of whales shifted slightly eastward during the ATOC blocks and the mean distance between the ATOC source and pods was greater during transmissions. Nonetheless, more whales were found close to the source when it was on, suggesting a more variable response rather than simple avoidance, with whales found both closer to, and farther away from, the source during transmissions.     

Pulp and paper mill waste pollution in the Swale,a tidal channel on the east coast of England

The effect of pulp and paper mill waste discharges in the Swale, a tidal channel on the southeast coast of England, has been studied. A pulsing tidal movement in the Swale results in effluent being trapped within the estuary for up to 20 days. This has resulted in adverse effects on the quality of the water and sediment along a substantial part of the estuary with the greatest effect occurring east of the mill in the direction of the residual current. A reduction in the dissolved oxygen concentration occurred along a 13-km stretch of the estuary with mean values falling to 53 % saturation near the mill. High levels of organic matter in the sediment reflect the deposition of material from the mill effluent stream and loss on ignition values of up to 12 % were found east of the mill, falling to 5 % within 4 km northwest of the mill. The macrofauna of the intertidal mudflats was typical of a stressed environment with a low number of species and with a few being represented by large numbers of individuals. The dominant species was the sabellid polychaeteManayunkia aestuarina which reached peak numbers of over 1.5 million m⁻², 1.5 km east of the mill. An increase in the total biomass near the mill is thought to be associated with organic enrichment from the mill wastes.     

Prairie Wolf Slough Wetlands Demonstration Project: A Case Study Illustrating the Need for Incorporating Soil and Water Quality Assessment in Wetland Restoration Planning,Design and Monitoring

In northeastern Illinois, restored wetlands are used to improve water quality in streams degraded by agriculture and urban development. Using freshwater wetlands to reduce nitrogen loading to lakes and rivers is well documented; however, there are fewer studies addressing their use to remove phosphorous. In 1998, a systematic water quality monitoring project was begun at Prairie Wolf Slough Wetland Demonstration Project, a restored palustrine emergent marsh wetland located on an abandoned farm field north of Chicago. The wetland drains 98 ha of mixed land uses into the Chicago River. Our objectives were to assess spatial and temporal variations in total suspended solids, soluble reactive and total phosphorous concentrations, and mass loadings and compute a mass balance and retention efficiency for these constituents. Water sampling was conducted from 1998 to 2003. In 2004, soil samples were collected from the marsh and an adjacent abandoned farm site and analyzed for soil test (Bray) phosphorus. The marsh effectively traps suspended solids but acts as a source of soluble reactive and total phosphorous to the river both during the growing and nongrowing seasons. Net export of phosphorous from the wetland was likely due to mobilization of orthophosphate as a result of anoxic conditions produced during inundation events. Often little consideration is given to the link between soil and water quality when locating restoration sites. Our study adds to a growing body of literature that clearly demonstrates the need for both soil and water quality assessments in wetland restoration planning, design, and monitoring.     

Application of multivariate statistics and toxicity indices to evaluate the water quality suitability for fish of three rivers in the Kruger National Park,South Africa

The water quality of the Olifants, Letaba and Luvuvhu rivers within the Kruger National Park was assessed for their suitability to sustain fish populations. Since water quality assessments result in huge datasets, principal component analysis and an aquatic toxicity index (ATI) were employed to reduce these to more manageable indices. Water quality changed over time, with metal concentrations decreasing, and high flows resulted in increased concentrations of suspended metals. The ATI indicated that metals had no major effect on lowering index values in any of the rivers, and that these values were affected by turbidity in both the Olifants and Letaba rivers, whilst nutrients such as ammonium and orthophosphates negatively affected index scores in the Luvuvhu River. Water quality has improved from the 1990s to 2011.     

Assessment of surface water quality in Legedadie and Dire catchments,Central Ethiopia,using multivariate statistical analysis

The quality of surface water in an area could be determined both by anthropogenic actions and natural processes. The current study assessed surface water quality in Legedadie and Dire catchments that cover a total area of 285 km2 in Central Ethiopia northeast of the nation’s capital Addis Ababa and within close proximity (20-30 m) from this city.. Accordingly, Addis Ababa is, and will continue to be, the major beneficiary of the the catchments which are in fact the primary sources of potable water supply to the city. Despite its potential ecosystem benefits, the catchment area was seriously affected by the rapid socioeconomic development phenomena that had been taking place in and around the city over the previous six decades. As a result, the catchment water resources are characterized by decades of deterioration because of severe pollution problems directly associated with mismanagement of natural resources coupled with other several factors. Hence, the current study was sought to examine the temporal and spatial determinants of catchment water pollutants. To that end, 14 water quality monitoring stations were selected and set up both in upstream and downstream parts of six rivers and two reservoirs. The water samples collected from different sites were monitored for 30 standard water quality parameters including nutrients, inorganic variable, and trace metals. Seasonal data were then measured for the 30 parameters monitored across two seasons (summer and autumn) over a two-year period (June 2014 – November 2015). The complex two-year seasonal data matrix that comprised of 3,660 observations was treated using multivariate statistical techniques: cluster analysis (CA), factor analysis/principal components (FA/PCA), and discriminant analysis (DA). CA successfully classified both the temporal (summer, autumn, and summer predominant) and spatial (natural, agricultural, urban, and mixed) clusters of water quality monitoring sites. Dimension reduction from FA/PCA was not as substantial as expected since it enabled only30% reduction from the original data matrix. On the other hand, DA procedures demonstrated the best result regarding data reduction and pattern recognition in both temporal and spatial analysis. It extracted data significantly and provided 5 parameters (Temp, pH, DO, salinity, and TN) to afford 96.8% right allocations during temporal analysis and only 7 parameters (pH, Turbidity, TN, Total hardness, Pb, Fe, and Cu) to yield 85.2% right allocations during the spatial analysis.Thus, these water quality parameters were most significant for seasonal and spatial water quality variation in the catchment. Therefore, DA enabled a significant reduction of the dimension of the original data matrix into a few significant parameters that affect water quality. In conclusion, the study demonstrated that multivariate statistical techniques are very useful for analysis and interpretation of complex water quality data sets for efficient assessment of water quality and identification of pollution sources as well as an effective understanding of the space and time effects of water quality.     

Response of the freshwater marsh species, Panicum hemitomon Schult., to increased salinity

SUMMARY. 1. Panicum hemitomon Schult. plants were colleeted from Louisiana's Mississippi River deltaic plain freshwater marsh and subjected to salinities of 5–12 ppt under controlled environment conditiotis.
2. The condition was designed to simulate salt stress resulting from storm surges, brine spills associated with oil recovery operations and salt water intrusion due to rapid subsidence and parallel increases in apparent sea level in Louisiana's coastal areas.
3. Plant stomatal conductance was reduced between 55 % and 80% and net photosynthesis declined between 20% and 67% in response to the different salinities within 1 day of salt application. Both responses lasted throughout the entire experiment.
4. Salinities ranging between 10 and 12 ppt resulted in tissue death in the plants 4 days after salt exposure.
5. In addition to the short-term impact of salt water influx on gas exchange of P, hemitomon reported here, the potential long-term effects on habitat change are discussed.     

Efficacy of three prevention strategies against legionella in cooling water systems

The efficacy of three different prevention strategies on legionella in cooling systems was studied. The strategies were as follows: (1) water temperature was lowered; (2) water quality was improved; or (3) the system was disinfected with polyhexamethylene biguanidechloride (PHMB) biocide or with 2-bromo-2-nitropropane-1,3-diol (BNPD) biocide. Lowering of water temperature was the most effective method to reduce the concentration of legionella in cooling systems. Improving of water quality resulted in a transitory disinfection effect. The additions of PHMB or BNPD decreased the concentrations of both legionella and heterotrophic bacteria in cooling water. The effect of biocides, however, lasted at the most only a few months. If possible, lowering water temperature and improving the water quality should be the primary practices for controlling bacterial growth in cooling systems. Regular biocide treatments should be incorporated into the maintenance procedures if technical improvements cannot be done or if their efficiency is too low.     

The hydrography of the southern Canada Basin, 2002

Physical and geochemical data collected in 2002 during a multi-disciplinary expedition across the southern Canada Basin are interpreted here to provide context for the biological program that included observations from the entire water column. The mixed layer was shallow (15–20 m) and depleted of nitrate, indicating it was the limiting nutrient. Below the mixed layer a strong, multi-layered halocline complex, consisting of Pacific-origin summer and winter waters and Atlantic-origin lower halocline water, occupied the water column down to ~200 m. Pacific and Atlantic-origin waters were shallower by 25–50 m in comparison to data collected in 1997/1998, suggesting a progressive decrease in Pacific-origin water extent. Fram Strait Branch waters were warmer everywhere in the southern Canada Basin, indicating the arrival of the pulse of anomalously warm Atlantic-origin water observed in the three upstream basins during the 1990s. The highest temperatures (1.13°C) were observed along the flank of the Northwind Ridge in the core of the topographically steered boundary current. Comparison with 1997/1998 observations showed that this pulse of anomalously warm water advanced ~430 km in 4 years with an apparent speed of ~0.34 cm/s. Observation of high temperatures at a station in the Canada Abyssal Plain suggest that the boundary current bifurcates north of the Northwind Ridge, with one branch continuing eastward into the basin and the other turning southward, following the ridge.     

太湖流域河流水质状况对景观背景的响应

为探索流域水质对景观背景的响应,以太湖流域为研究对象,在0.5—24 km共9个尺度上运用冗余分析研究了土地利用、河网密度、降水量、地形等景观背景因子与河流水化学指标的关系。结果表明:2006—2010年太湖流域河流水质状况总体较差,但整体有逐渐改善的趋势,超标水质指标主要包括总磷(TP)、氨氮(AN)、生化需氧量(BOD)、化学需氧量(COD)和溶解氧(DO),上游地区主要表现为林区和平原水网区的差异,下游地区主要表现为河段上下游间的差异。河流水质受到多种景观背景因子的综合影响,并表现出尺度依赖性和区位差异性。AN、TP、DO在流域上游与聚落用地正相关,在下游则与耕地、河网密度正相关。COD、BOD在流域上游主要与自然湿地负相关,与人工湿地正相关,在下游则与坡度负相关,与河网密度正相关。总方差贡献率在上下游表现出一致的尺度依赖特征,均在较小(0.5—1 km)和较大(16 km)两个尺度上具有较高的解释能力。自然湿地和坡度,河网密度和耕地分别为上游、下游地区在较小和较大尺度上解释能力最高的景观因子。     

Environmental quality assessment of the St. Clair River as reflected by the distribution of benthic macroinvertebrates in 1985

A benthic macroinvertebrate and sediment chemistry study of the St. Clair River from Lake Huron to Lake St. Clair was conducted in the spring of 1985. The purpose of the. study was to evaluate the environmental quality of the nearshore areas and assess the effectiveness of industrial and municipal abatement programs that have been implemented since 1977.A total of 112 macroinvertebratd taxa was collected from the river. Classification analysis indicated that 7 macroinvertebrate communities were evident in the river. Discriminant analysis suggested that physical habitat characteristics explained the distribution of 4 benthic communities, while sediment contaminants explained the distribution of 3 benthic communities. These analyses showed that the environmental quality of a 12 km stretch of the river along the Canadian shoreline had been degraded, probably by industrial waste discharges and spills. Toxic conditions were evident along the waterfront of Dow Chemical Canada Inc., probably a result of the combined effects of chlorinated organics, oils and greases, and mercury (historical contaminant) in the sediments. In contrast, the invertebrate fauna throughout the remainder of the St. Clair River reflected meso-eutrophic conditions, typical of a large, unstressed river.A comparison of the environmental quality as reflected by the benthic invertebrate fauna in 1985 with that in 1977 suggests that the abatement programs implemented over the past decade have improved the environmental quality along the Canadian side of the river. The total length of river adversely affected by waste discharges from Canadian industries and municipalities decreased from 21 km in 1977 to 12 km in 1985.     

Late Holocene sea level and reef-flat progradation, Phuket, South Thailand

 Fringing reefs growing in the muddy waters of SE Phuket contain fossil, former reef-front, massive corals that protrude above the intertidal reef flat. The top surfaces of some of these massive fossil corals have been dated and surveyed. The results indicate that these reefs commenced growth 6000 y ago when the sea level (low spring tide) was 1 m above present and that the average rate of reef-front progradation was 1.7 cm per year. Accepted: 22 May 1998     

GROWTH, PRIMARY PRODUCTIVITY, AND NITROGEN FIXATION POTENTIAL OF NODULARIA SPP. (CYANOPHYCEAE) IN WATER FROM A SUBTROPICAL ESTUARY IN THE UNITED STATES

Nodularia is a halotolerant, filamentous, dinitrogen-fixing cyanobacterium that forms massive blooms in some coastal oceans, estuaries, and saline lakes worldwide. Although the genus is globally distributed, its blooms are sporadic and appear to be confined to certain water bodies. Blooms are frequently associated with phosphorus enrichment; therefore Nodularia may benefit from increased anthropogenic nutrient loading to coastal waters. We studied the potential for Nodularia to grow in the nitrogen-limited Neuse River Estuary (North Carolina, U.S.A.) with laboratory growth experiments in Neuse River Estuary water and by examining physico-chemical data from the estuary. Analysis of nutrients (nitrogen and phosphorus), salinity, and temperature data from the Neuse River Estuary between 1994 and 1998 revealed that suitable conditions for Nodularia prevailed during the summer of each of these years for time spans ranging from 1.5 to 5 months. Growth of two laboratory strains in Neuse River Estuary water was as fast or slightly slower than in artificial growth medium, as long as the culture inoculum had phosphorus reserves. Phosphorus addition did not stimulate growth of already phosphorus-sufficient inocula. Phosphorus starvation of the inoculum before the experiment decreased growth rates in the estuarine water unless additional phosphorus was supplied. Although phosphorus addition had a stimulatory effect on dinitrogen fixation and productivity, the effect differed for the two Nodularia strains. Results suggest that growth of Nodularia in North Carolinian estuaries is possible, and that such growth would be phosphorus-limited at times. Phosphorus availability may determine the times and locations for potential establishment of Nodularia in this and similar estuarine ecosystems.     

Naked Amoebas and Bacteria in an Oil-Impacted Salt Marsh Community

Populations of soil amoebas were monitored in two salt marshes in Staten Island, NY for 2 years. One site, Gulfport Reach on the Arthur Kill, has been highly impacted by numerous oil spills. In particular, in 1990 a massive no. 2 fuel oil spill from a ruptured pipe flooded the area; its sediments had total petroleum hydrocarbon (TPH) concentrations in the range 800-46,000 ppm. A reference site 11 km away, on the Atlantic coast, had low TPH levels. Amoeba population densities were in general higher in the impacted sediments. In laboratory microcosm experiments, sediment samples from unimpacted sites were treated with added fresh (unweathered) hydrocarbons (no. 2 fuel oil) and cultured; these also yielded higher amoeba numbers than untreated controls. Four distinct amoeba morphotypes were monitored. Changes in population levels of total amoebas were correlated in the two sites, particularly for morphotype 2 (r = 0.83). The ratios of total amoebas to total bacterial numbers were also correlated (r = 0.85) between the sites. This suggests the amoebas may function as generalists, and that their trophic relation to bacterial prey is not much affected by the presence of petroleum hydrocarbons, but rather may reflect regional parameters such as ambient temperature or other physical factors.     

Effect of land use types on stream water quality under seasonal variation and topographic characteristics in the Wei River basin,China

The effect of topographic characteristics of land uses on stream water quality must be addressed for a better understanding of the complex relationship between land use and stream water quality. In this study, Geographic Information System (GIS) and Pearson correlation analysis were used to determine whether there were relationship between land use types and stream water quality at the sub-basin scale in the Wei River basin, China, during the dry and rainy seasons in 2012. Temporal variation of these relations was observed, indicating that the relationships between water quality variables and different land uses were weaker in rainy seasons than that in dry seasons. Compared with other land uses, agriculture and urban lands had a stronger relationship with water quality variables in both rainy and dry seasons. Topographic characteristics of land use were employed to further analyze these relationships. The results showed that seasonal variation also occurred in the complex relationship, and land uses in steeper slopes generally had a stronger influence on stream water quality than those in flatter ones. For the riparian zone of each sampling site, the slope coefficients were weaker than those at the sub-basin scale. Land use type near stream water was generally a better indicator for the effectiveness of water quality. These results suggest that the slope and proximity should be taken into account for better land use management.     

Aluminium speciation in the Vienne river on its upstream catchment (Limousin region, France)

The aim of this study was to investigate the speciation of aluminium in the river Vienne on its upstream catchment (Limousin region, France) over a period of seven years (May 1998-September 2004) in order to assess harmful effects on aquatic life. Two sampling points were selected: the first at 4 km from the spring (Peyrelevade), and the second one at 89 km from the spring (Royères). The aluminium speciation was computed with Mineql+ 4.5 speciation software. Organic matter and phosphorous play a major role in aluminium speciation. If we consider the free aluminium ion (Al3+) as being the only toxic form of aluminium, the concentrations of toxic forms recorded at Peyrelevade and Royères were always below the toxic values for fish. However, if the sum of the concentrations of Al3+, Al(OH)2+, Al(OH)2+ and Al(OH)4- is taken into consideration, the concentration of aluminium recorded may have adverse effects on aquatic life in the upstream catchment of the river Vienne. Al(OH)4- is the major contributor to the concentration in toxic aluminium recorded. In general, Al(OH)4- forms appears in water during the summer with water alkalinisation due to an increase in photosynthetic activities.     

Testing the Sensitivity of Phytoplankton Communities to Changes in Water Temperature and Nutrient Load, in a Temperate Lake

Freshwater lakes are biologically sensitive to changes in the surrounding environment and the impacts that such changes have on their water quality are of considerable ecological, recreational and economic importance. In this study the phytoplankton community model, PROTECH, was used to experiment with the effects of elevated temperatures and increased nutrient load on phytoplankton succession and productivity. The response of a phytoplankton community to combined incremental changes in these drivers was analysed, in order to elucidate the resulting ecological changes. Annual mean phytoplankton biomass increased with increases in temperature and nutrient loading, although the latter had the larger effect. The phenology of the dominant phytoplankton taxa changed with increasing water temperature; the three spring blooming species all peaked earlier in the year. The simulated summer bloom of Anabaena became earlier in the year and the Chlorella bloom later. The increased phytoplankton biomass was largely dominated by the cyanobacterium Anabaena, which was especially prevalent during the summer bloom. This resulted in a progressive loss of phytoplankton biodiversity with increasing water temperature and nutrient supply. Model experimentation showed that whilst both factors greatly affected the community, the changes to nutrient loading generally had the greater effect and that at low nutrient levels the effect of water temperature change was reduced considerably. Finally, the model predicted that cyanobacteria have the potential to dominate the phytoplankton community, with clear consequences for water quality, and that this dominance was at its greatest when high water temperatures were combined with high nutrient loads.