Multiple parameters were monitored during an 18-month period in two karst groundwater basins in Woodford County, Kentucky, in order to assess the effects of land use on water quality. Blue Hole Spring drains a primarily urban area, whereas spring SP-2 drains an agricultural area. Water-quality parameters were monitored manually weekly or biweekly, as well as more frequently during storms. Discharge (Q), temperature (T), specific conductance (SC), and turbidity were continuously monitored and logged at 15-minute intervals. It is hypothesized that pathogen and sediment concentrations would be lower at SP-2 than at Blue Hole Spring due to differences in land use between basins. Average Q was greater at Blue Hole than at SP-2, and SC values were greater at Blue Hole than at SP-2 for 70 of 71 sample sets. During two monitored storms, as Q increased, SC decreased and turbidity increased. Biweekly Blue Hole fecal coliform (FC), total coliform (TC), and atypical colonies (AC) values averaged 160, 3,600, and 40,000 cfu/100 mL, respectively, and fluctuated more than at SP-2. Biweekly SP-2 FC, TC, and AC values averaged 130, 2,000, and 8,300 cfu/100 mL, respectively. Biweekly values for AC/TC averaged 14.29 at Blue Hole and 6.27 at SP-2. AC/TC ratios were greater at Blue Hole than at SP-2 for 29 of 31 biweekly sample sets. There is a statistically significant difference between the biweekly data sets from the two sites, as well as between data collected under WET and NORMAL flow conditions at each site. Male-specific coliphage (MSP) was detected in most samples collected from Blue Hole, but was never detected at SP-2. Given the proximity of the basins, differences in water quality appear to reflect differences in land use, as hypothesized. Results were similar to other studies in the Inner Bluegrass region. For both Blue Hole and SP-2, wet weather was associated with changes in certain parameters. This study has also shown that the AC/TC ratio appears to be a valid tool for determining the source of contamination within karst ground-water systems as well as in surface water.

Agriculture and the use of arable land have long been assumed to be one of the key drivers behind eutrophication of lakes. However, little is known about how early agriculture has affected lakes in the past. The aims of this study were: i) quantify the within-region variability in historical land use and its linkage to soil cover and ii) test if the sediment geochemistry could be used to reconstruct inputs of phosphorus from early agricultural activities. The within-region variability was determined by digitalizing historical maps covering four centuries from the 18th to the 21st century for six selected regions across Sweden. To assess historical changes in lake-water phosphorus, a 6 m long 14C-dated sediment core from Ekoln was analyzed. The core was analyzed for 24 elements by X-ray fluorescence spectroscopy (XRF) together with the total concentration of nitrogen and carbon and their isotopes (δ13C, δ15N). Results show that there was a statistically significant difference (P<0.05) in agricultural activities between regions with soils rich in fine texture classes compared to soils with a more coarse texture. Agriculture also became less dependent on fine-grained soils due to new technological implements following the industrialization. The reconstructed long term-trend in Ekoln indicate limited inputs of phosphorus from early farming and that the lake had higher concentrations of phosphorus throughout the last millennia. Therefore, early farming was unlikely to be the prime driver of high phosphorus loadings, and that other factors should be considered, e.g. extensive urbanization and inputs of wastewater effluent.

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Mine water effluent contains high levels of nitrogen due to residues from undetonated ammonium- nitrate based explosives. Excess nitrogen in aquatic ecosystems can cause eutrophication. Within a mining area, tailings and clarification ponds have the potential to reduce nitrogen levels by biological uptake of nitrogen into growing algae and denitrification in pond sediments. A previous study at the LKAB Kiruna mine investigated the potential nitrogen removal within the tailings and clarification ponds. The study showed that about 1-10 tonnes of nitrogen were removed each year, and that the removal by denitrification was limited by carbon.  The aim of this master thesis was to investigate if additions of different carbon compounds could improve the denitrification in sediment from the clarification pond at the LKAB Kiruna mine site. It was also of interest to see if the composition of the edogenous microbial community involved in nitrogen reduction changed after the treatments. Samples of sediment and pond water were collected in January 2014 and a laboratory experiment was set up where sediment and water was incubated with carbon additions under anoxic conditions. Three different carbon sources were tested: sodium acetate, hydroxyethyl cellulose and green algae. Pond water without additional carbon was used as a control. The sediment was incubated eight weeks at 20 °C with weekly water exchange and carbon addition. The removed water was analyzed to determine the amount of nitrogen removed. At start and after ending the incubation, potential denitrification in the sediment was determined with an enzymatic assay and the size of the genetic potential of nitrogen reduction was determined.  At start, the enzymatic assay showed that the potential denitrification rate in the sediment of the clarification pond at the LKAB Kiruna mine was not immediately enhanced by addition of carbon. However, during the incubation the removal of nitrate was enhanced by external carbon sources. Algae were a good carbon source, since the denitrifying community grew, the potential denitrification increased four times after incubation and the removal of nitrate was next to complete in the end of the incubation. The addition of cellulose also enhanced the denitrification activity to some extent and the abundance of genes coupled to denitrification increased. Further studies are needed to assess the practical use of external carbon sources like algae and plant material and how they would function in and potentially also affect a large, cold and complex system like the LKAB mining site.

The metal mining history goes thousands of years back. The downside of the mining industry is the large amount of tailings created during the mining operations. Drainage and leaching of heavy metals from these tailings may cause major environmental problems including acid mine drainage and leaching of heavy metals. This study examines a pond located near an old mining site, where part of the old mining facility has been recently (1990) restored. The objective was to assess eventual metal contamination from historical mining and the recently performed restoration using a sediment core as a natural archive of historical metal inputs to the pond. I found that the concentration of lead, copper, zinc and nickel were elevated in comparison to background levels in sediment. Elevated concentrations were found in the deep layer of the sediment core, 14-20 cm with an estimated age of ca 100 years. The highest concentrations were found near the surface (3-4 cm depth). Conclusion of the study was that the early mining operations has affected the ponds metal contamination history. The restoration of the mining site had weak impact on the pond, but may contribute to the high metal concentration in recent sediments.

Nutrients in the sediments of Lake Manitoba’s south basin are resuspended regularly due to its shallow, polymictic nature. In 2009 short sediment core samples were used to determine an internal available nutrient load from sediment of 17,533 tonnes total nitrogen (TN) and 167 tonnes total phosphorous (TP). Water samples were collected at the Whitemud River and Assiniboine River Diversion (ARD) to determine the N and P input to the lake, resulting in an estimate of a total point source input of 3,547 tonnes of TN and 1,130 tonnes of TP. Open water samples were collected to determine a suspended content of 9.2 tonnes of TN /km2 or and 1.7 tonnes of TP/km2. The ARD is the largest contributor of TP to the south basin. The internal sediment pool is a significant source of TN, and when the ARD does not operate, the largest input of TP to the south basin.

The lower continental slope of Morocco’s west coast consists of Triassic-age salt manifested in the form of diapirs, tongues, sheets, and canopies, and both extensional and compressional structures that result from salt movements. Salt diapirism and regional tectonics greatly influenced a broad spectrum of depositional processes along the margin. Mapping of a 1064-km2 (411-mi2) seismic survey acquired in the Safi Haute Mer area reveals that Jurassic to Holocene salt mobilization has induced sedimentation that manifests itself in gravity slumps and slides and debris flows. An east-west–trending structural anticline located downdip of the salt-influenced region, was activated during the Atlas uplift (latest Cretaceous) and shaped much of the lower continental slope morphology from Tertiary time until present. The largest of the mass transport deposits (MTC) is a 500-m (1640-ft)-thick Cretaceous-age unit that spans an area of up to 20,000 km2 (7722 mi2). Seismic facies composing the MTC are (1) chaotic, mounded reflectors; (2) imbricated continuous to discontinuous folded reflector packages interpreted to represent internal syn-depositional thrusts; and (3) isolated, thick packages of continuous reflectors interpreted to represent transported megablocks (3.3 km2 [1.3 mi2]). The latter show well preserved internal stratigraphy. The MTCs originated from an upslope collapse of a narrow shelf during the earliest phases of the Alpine orogeny. Seismic geomorphologic analysis of the non-salt-deformed sections reveal numerous linear features that are interpreted as migrating Mesozoic-age deepmarine sediment waves. Three styles of sediment waves have been identified. These include: (1) type J1—small (less than 17 m thick) and poorly imaged, Jurassic in age, ridges that have wavelengths of up to 12 km and crest-to-crest separations of less than 1 km; (2) type K1—early Aptian constructional sediment waves (~110 m thick) that appear to show some orientation and size variations which suggest an influence on currents by salt-influenced seafloor topography, and (3) type K2—latest Albian and earliest post-Albian sediment waves exhibiting wave heights of 40 m and crest-to-crest separations of 1 km, that are continuous across the entire study area and show evidence of up-slope migration.

This study combined sedimentation, sediment chemistry and benthic community data from three Oncorhynchus mykiss cage farms in Ontario, along with a laboratory bioassay to examine the effects of aquaculture waste loading. Waste loading rates, as well as sediment TC, TN, TP and metal (Cu, Zn) concentrations were highest beneath the cage and decreased exponentially with distance. During the 21-day bioassay, Tubifex (Oligochaeta, Naididae), Chironomus (Diptera, Chironomidae) and Sphaerium (Bivalvia, Pisidiidae) were subjected to a gradient of waste loading. Survival and growth of Sphaerium simile was highest at intermediate levels of waste loading. Chironomus riparius growth increased with increasing waste addition. Tubifex tubifex growth increased with exposure to fish waste, compared with the control. Until this study, there were no predictions for thresholds of effect at freshwater cage farms in the literature. The proposed threshold of effect on freshwater benthos is 2.0 - 3.0 g C m-2 day-1.

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