Effects of introduced fish on macroinvertebrate communities in historically fishless headwater and kettle lakes

Widespread fish introductions have led to a worldwide decline in the number of fishless lakes and their associated communities. Studies assessing effects of fish stocking on native communities in historically fishless lakes have been limited to high-elevation headwater lakes stocked with non-native trout. Little is known about the effect of fish stocking in historically fishless and hydrologically isolated lowland kettle lakes. We compared the effects of introduced fish on macroinvertebrate communities in kettle lakes stocked with centrarchids, salmonids, and cyprinids, and headwater lakes stocked with brook trout (Salvelinus fontinalis) in Maine, USA. Fish had significant effects on macroinvertebrate community structure in both lake types, with reduced species richness and abundances of taxa characteristic of fishless lakes. The effects of introduced fish were more pronounced in headwater lakes despite a less diverse fish assemblage than in kettle lakes. We attribute this to abundant submerged vegetation providing refuge from fish predation and reduced stocking frequency in kettle lakes. We assessed effects of stocking duration on macroinvertebrates in a subset of headwater lakes with known dates of trout introduction. Species richness and abundance of most taxa declined within 3 years following trout introduction; however, richness and abundance were least in lakes with long stocking histories (?40 years). Macroinvertebrates previously identified as fishless bioindicators were absent from all stocked lakes, indicating that trout rapidly eliminate these sensitive taxa. Conservation of this historically undervalued ecosystem requires protecting remaining fishless lakes and recovering those that have been stocked.     

Evidence for a depth refuge effect in artisanal coral reef fisheries

Natural refuges can play a fundamental role in protecting species from overexploitation but have not been adequately quantified in the marine environment. We quantified the effect of a depth refuge on all fish species in an artisanal coral reef fishery in Zanzibar, Tanzania by comparing changes in fish species richness and relative abundance with depth at five fished and three unfished reefs across the region. Commercial species richness was depleted by 15.1% at shallow depths in fished reefs, but there was no difference between the reefs deeper than seven metres. Non-commercial species were not affected by fishing or depth. Evidence for similar patterns in fish communities in other countries and depth-limitations to artisanal fishing methods imply this effect is widespread. The depth refuge effect could be sustaining coral reef fisheries and should be taken in to account before implementing policies or subsidies that encourage or allow fisheries to exploit deeper waters.     

Effectiveness of five small Philippines’ coral reef reserves for fish populations depends on site-specific factors, particularly enforcement history

Community-managed, no-take marine reserves are increasingly promoted as a simple, precautionary measure to conserve biodiversity and sustain coral reef fisheries. However, we need to demonstrate the effects of such reserves to those affected by the loss of potential fishing grounds and the wider scientific community. We surveyed changes in fish communities in five small marine reserves in the central Philippines and three distant Control sites over seven years. We conducted underwater visual censuses of 53 fish families within the reserve (Inside), with a kilometre of the boundary (Outside) and at Control sites. We found significant differences between fish communities Inside and Outside the reserve only at the two sites with strictest compliance with fishing prohibition, while there were significant differences to distant Control sites in all cases. The strongest responses to reserve protection were found in predatory fishes (groupers and breams) and in butterflyfish. Other abundant fish families showed weak effects of protection. For all taxa analysed, we found significant effects of reserve Site and Site × Treatment interactions. The detection of fish responses to reserves is complicated by potential spillover effects, site-specific factors, particularly compliance, and the difficulty of identifying appropriate control areas.     

Peat–water interrelationships in a tropical peatland ecosystem in Southeast Asia

Interrelationships between peat and water were studied using a hydropedological modelling approach for adjacent relatively intact and degraded peatland in Central Kalimantan, Indonesia. The easy to observe degree of peat humification provided good guidance for the assignment of more difficult to measure saturated hydraulic conductivities to the acrotelm–catotelm hydrological system. Ideally, to prevent subsidence and fire, groundwater levels should be maintained between 40 cm below and 100 cm above the peat surface. Calculated groundwater levels for different years and for different months within a single year showed that these levels can drop deeper than the critical threshold of 40 cm below the peat surface whilst flooding of more than 100 cm above the surface was also observed. In July 1997, a dry El Niño year, areas for which deep groundwater levels were calculated coincided with areas that were on fire as detected from radar images. The relatively intact peatland showed resilience towards disturbance of its hydrological integrity whereas the degraded peatland was susceptible to fire. Hydropedological modelling identified areas with good restoration potential based on predicted flooding depth and duration. Groundwater level prediction maps can be used in fire hazard warning systems as well as in land utilization and restoration planning. These maps are also attractive tools to move from the dominant uni-sectoral approach in peatland resource management toward a much more promising multi-sectoral approach involving various forestry, agriculture and environment agencies. It is demonstrated that the combination of hydrology and pedology is essential for wise use of valuable but threatened tropical peatland ecosystems.     

Variations in microbial community composition through two soil depth profiles

Soil profiles are often many meters deep, but with the majority of studies in soil microbiology focusing exclusively on the soil surface, we know very little about the nature of the microbial communities inhabiting the deeper soil horizons. We used phospholipid fatty acid (PLFA) analysis to examine the vertical distribution of specific microbial groups and to identify the patterns of microbial abundance and community-level diversity within the soil profile. Samples were collected from the soil surface down to 2 m in depth from two unsaturated Mollisol profiles located near Santa Barbara, CA, USA. While the densities of microorganisms were generally one to two orders of magnitude lower in the deeper horizons of both profiles than at the soil surface, approximately 35% of the total quantity of microbial biomass found in the top 2 m of soil is found below a depth of 25 cm. Principal components analysis of the PLFA signatures indicates that the composition of the soil microbial communities changes significantly with soil depth. The differentiation of microbial communities within the two profiles coincides with an overall decline in microbial diversity. The number of individual PLFAs detected in soil samples decreased by about a third from the soil surface down to 2 m. The ratios of cyclopropyl/monoenoic precursors and total saturated/total monounsaturated fatty acids increased with soil depth, suggesting that the microbes inhabiting the deeper soil horizons are more carbon limited than surface-dwelling microbes. Using PLFAs as biomarkers, we show that Gram-positive bacteria and actinomycetes tended to increase in proportional abundance with increasing soil depth, while the abundances of Gram-negative bacteria, fungi, and protozoa were highest at the soil surface and substantially lower in the subsurface. The vertical distribution of these specific microbial groups can largely be attributed to the decline in carbon availability with soil depth.     

A large-scale conservation perspective considering endemic fishes of the North American plains

Regions with unique habitats often harbor endemic taxa associated with temporally stable habitats. We identified such habitats that sustain endemic fishes in the plains of North America. We also summarized threats to their conservation and identified remnant habitats that still harbor endemic fishes (refuges) based on post-1989 surveys. Major springs, smaller, spring-fed streams, larger rivers, and euryhaline habitats were associated with a total of 49 endemics. Endemism was attributable to climatic refugia associated with each habitat type and dispersal limitation among major river drainages and springs. Forty-one endemic fishes (84%) were declining or extinct. Dewatering, habitat fragmentation, and habitat degradation were main causes of declines, often present together. Pollution and non-native species were also threats in many cases. Evidence for 53 existing refuges was found. We considered 34 refuges to be “high-quality” because they harbored three or more endemics. Twenty of these (those with available data) maintained consistent streamflow regimes for at least 50 years up to 2009. Case studies suggest high stream length, more natural flow regimes, and fewer direct human impacts are features of high-quality refuges, but extinction thresholds are unquantified and extinction debts of refuges are unknown. Limited information on past extinctions suggests drought, a natural feature of the plains, combines with other threats to eliminate remnant endemic populations. Long-term conservation planning requires identification, protection, and restoration of high-quality refuges to reduce extinction risk, especially during future drought periods. Planning should be integrated with regional water resource planning, given scarcity of water in the region.     

Rooting patterns of four crop legumes in response to seed-placement depths in the dry season

Abstract

On sandy paddy fields, key factors for successful crops in the dry season without irrigation are a shallow water table and practices such as deep seed-placement but only some legume species are adapted to such conditions. To understand the adaptation of legume species to deep seed-placement over shallow water tables, we studied their rooting patterns on two sandy soils. Cowpea (Vigna unguiculata), mungbean (Vigna radiata), peanut (Arachis hypogaea) and soybean (Glycine max) seeds were sown shallow (～5 cm) or deep (～15 cm) in deep sandy soils after harvesting rice in two shallow water table locations in north-east Thailand. The legumes depended mainly on capillary water rising from the water table and none experienced water deficit throughout the growing season. Generally, deeper seed-placement decreased overall root dry weight, but it increased the root surface area to weight ratio. Deep seed-placement promoted a greater fraction of root growth into the subsoil for cowpea (86–99% of total root length), mungbean (61–93% of total root length) and peanut (78–98% of total root length) where the soil contained more water throughout the growing season. Moreover, deep seed-placement at the site with the lower water table promoted deeper penetration of roots of cowpea (～20 cm deeper), mungbean (～20–40 cm deeper) and peanut (～20–40 cm deeper) which improved water access, especially late during the growing season when topsoils dried to close to wilting point. Unlike other species, the soybean rooting pattern did not respond much to seed-placement depths, or soil moisture.     

Long-term experiments with different depths of mouldboard ploughing in Sweden

With the main objective to produce a basis for advice to farmers concerning optimal ploughing depth under various conditions, a series of field experiments were initiated throughout Sweden. At 19 sites on various soils (clay content 72–521 g kg⁻¹, organic matter content 21–89 g kg⁻¹) mouldboard ploughing to about 15, 22 and 28 cm depth was repeated annually for up to 17 years. The total number of location-years was 241. Traditional farming had previously been practised at the sites, including annual mouldboard ploughing to 20–25 cm depth. Spring-sown barley (Hordeum vulgare L.) and oats (Avena sativa L.) were the most frequent crops but many other crops were grown less frequently. Crop residues were generally returned to the soil; straw was chopped at harvest. Post-emergence herbicides were regularly used, generally resulting in an adequate control of annual weeds. However, the control of perennial weeds, particularly couch grass (Elymus repens L. Gould) was often inadequate. At ploughing depths of 22 and 28 cm, the mean crop yields were 2% and 3%, respectively, higher than at 15 cm. However, the results varied considerably between sites. In soils with a high silt content, the shallowest ploughing resulted in up to 10% higher yield than deeper ploughing, provided the control of perennial weeds was adequate. The main reason seemed to be improved structural stability in the surface soil because the concentration of organic matter in this layer became higher the shallower the ploughing. In clay soils with relatively stable structure, as well as in sandy soils, the deepest ploughing resulted in the highest yields, probably because of the deeper loosening. At sites where perennial weeds imposed problems, the weed control was better the deeper the ploughing, sometimes increasing the relative yield after deeper ploughing by several percent as compared with shallow ploughing. Most of this effect was obtained already at the intermediate ploughing depth. The results led to the following conclusions for Swedish agriculture. It may be profitable to plough sandy soils annually as deep as 30 cm, coarse sandy soils perhaps even deeper. In clay and clay loam soils, ploughing deeper than 20–25 cm generally cannot be recommended. In silty soils with an unstable structure, mouldboard ploughing, if any, should be shallow (≤15 cm), and perennial weeds should be controlled by other methods.     

A study of the oxygen regime and rooting depth in deep peat under plantations of Sitka spruce and lodgepole pine

Abstract. Rooting depth, watertable depth and oxygen regime were measured in plots of Sitka spruce, lodgepole pine and a 50% mixture of each species planted on a deep unflushed blanket peat. The water-table was about 10 cm deeper and roots occurred about 2 cm deeper under the pine than under the spruce or the mixture. In addition the mean concentration of oxygen at 50 cm depth was significantly larger under the pine and the mixture than under the spruce, showing that the rapid early growth of the pine had started to dry the peat. There was no evidence of any improvement in the growth of the spruce in the mixture compared to the pure Sitka spruce, suggesting that the expected nursing benefit had not occurred.     

Methanogen activity in relation to water table level in two boreal fens

We studied methanogen activity—measured by in vitro methane production potential and by detection of the messenger RNA (mRNA) of a functional gene—in two boreal fens under high and deep water table (WT) level conditions resulting from a rainy growing season and a dry growing season. The depth of the highest CH₄-producing layers differed between the years. In the wet year, the highest CH₄ production rate was around 20 cm below the mean WT. In the dry year, the highest rates were measured close to the peat surface, well above the mean WT. The distribution of activity in the peat profiles of the two fens appeared to be site specific. Under deep-WT conditions, CH₄ production potential was generally lower than that under high-WT conditions. Detection of the mRNA of the methanogen-specific mcrA gene indicated in situ methanogenesis in both water-saturated peat (below the WT) and unsaturated peat (above the WT). Analyses of DNA-derived and mRNA-derived methanogen community structures showed greater similarity between those two in water-saturated peat than in unsaturated peat. This suggested that favorable conditions promoted the activity of most members in methanogen communities, but unfavorable conditions showed differences between distinct community members in adaptation to adverse conditions.     

Effects of tillage depth on organic carbon content and physical properties in five Swedish soils

The soil tillage system affects incorporation of crop residues and may influence organic matter dynamics. A study was carried out in five 15–20 year old tillage experiments on soils with a clay content ranging from 72 to 521 g kg⁻¹. The main objective was to quantify the influence of tillage depth on total content of soil organic carbon and its distribution by depth. Some soil physical properties were also determined. The experiments were part of a series of field experiments all over Sweden with the objective of producing a basis to advise farmers on optimal depths and methods of primary tillage under various conditions. Before the experimental period, all sites had been mouldboard ploughed annually for many years to a depth of 23–25 cm. Treatments included primary tillage to 24–29 cm depth by mouldboard plough (deep tillage) and to 12–15 cm by field cultivator or mouldboard plough (shallow tillage). Dry bulk density, degree of compactness and penetration resistance profiles clearly reflected the depth of primary tillage and substantially increased below that depth. Compared to deep tillage, shallow tillage increased the concentration of organic carbon in the surface layer but decreased it in deeper layers. Total quantity of soil organic carbon and carbon–nitrogen ratio were unaffected by the tillage depth. Thus, a reduction of the tillage depth from about 25 cm to half of that depth would appear to have no significant effect on the global carbon cycle.     

Field investigations of soil hydrological properties of fen soils in North‐East Germany

To investigate the changes of hydrological properties of peat soil in course of soil development, field measurements at 84 fen sites (Histosols) in 19 fen regions of North‐East Germany were carried out. Capillary water supply at all the stages of soil development was not limited up to 70 cm of ground water level. Worsening of plant water supply was the result of mud accumulation in the capillary fringe, ground water levels located deeper than 70 cm below soil surface, low hydraulic conductivity in the ground water zone, and hysteresis effects, affected by high dynamics of ground water level during the day.     

Size and phenotypic structure of microbial communities within soil profiles in relation to different playing areas on a UK golf course

Amenity turf accounts for up to 4% of land‐use in urban areas, providing key refuges for both above‐ and below‐ground biodiversity. Golf courses occupy the largest surface area of all sports facilities; however, only a limited amount of microbial ecology has been carried out to investigate differences in the size and structure of microbial communities of the soil. The soil microbial community is a key agent in nutrient cycling and delivery of other ecosystem goods and services; however, there has been little work focused on amenity turf ecosystems in the UK. A study of soil microbial community size and structure, on the range of playing areas maintained for the game of golf at a single golf course in relation to depth through the soil profile, was carried out. Soil from different playing areas showed significant differences in the size (measured using chloroform fumigation extraction) of the microbial community (P < 0.01), with a greater concentration of microbial biomass at 0–75 mm from the surface, compared with deeper zones (P < 0.01). Principal component analysis of phospholipid fatty acid (PLFA) biomarkers indicated that the community structure was significantly different at 0–75 mm from the surface on all areas of the golf course investigated (P < 0.05, in all cases). The PLFA biomarkers consistently associated with such discrimination were 16:0 and 18:1ω9 c. These findings suggest that there is a consistently larger and similarly structured microbial community associated with the surface thatch layer, commonly found in amenity turf.     

Long-term nitrogen fertilization alters microbial community structure and denitrifier abundance in the deep vadose zone

Purpose

The excessive use of nitrogen (N) fertilizer in intensive agriculture has increased nitrate leaching into groundwater, but its impacts on N transformation processes and the associated microbial communities in the deep vadose zone remain unclear.

Materials and methods

Soil samples from 0–1050 cm depth were collected from a 20-year field experiment with two N fertilization treatments: 0 (N0) and 600 kg N ha^?1 year^?1 (N600). Amplicon sequencing and quantitative PCR analyses were performed to profile the vertical distribution of soil microbial communities and denitrification genes.

Results and discussion

The soil microbial community structure and diversity were strongly influenced by soil depth and N fertilization. The 250 cm depth was identified as a threshold depth, as dramatically different microbial communities were found below and above this depth. Quantitative PCR results showed that the absolute abundance of denitrification genes decreased with increasing soil depth.

Conclusion

This study elucidated the profound effects of long-term N input on the composition and diversity of the microbial communities and the abundance of denitrifiers in the deep vadose zone. Our results provide basic information for use in mitigating nitrate leaching by enhancing microbial denitrification in deep vadose zones in intensive agricultural areas.

     

Exposure to Bioaerosol from Sewage Systems

We assessed the impacts of a specific conductance gradient attributable to treated coal-mining discharges on the fish communities of a southwestern Pennsylvania stream. Total dissolved solids concentrations were determined from specific conductance values. A total of 10,940 fish representing seven families and 42 species/hybrids were collected from 17 stations over the entire survey. Species richness, density, and the coefficient of community loss (I) showed marked impairment at the two stations directly below the discharges and the downstream recovery was interrupted at one station by untreated discharges from a mine refuse pile. Species richness declined from 28 at the reference site to 7 at the station directly below the treated effluents. This study suggests that the threshold for in-stream conductivity impairment to fish communities in this region is in the range of 3,000–3,500 µS/cm and 2,000–2,300 mg/l of total dissolved solids, respectively.     

Status of Fish and Macroinvertebrate Communities in a Watershed Experiencing High Rates of Fossil Fuel Extraction: Tenmile Creek, a Major Monongahela River Tributary

Over the summer and fall seasons, 2006?C2010, we surveyed the fish and macroinvertebrate communities of the Tenmile Creek basin in southwestern Pennsylvania, an area undergoing accelerated extraction of energy resources??historically coal and more recently natural gas associated with the Marcellus formation. Tenmile Creek, its major South Fork (SF), and numerous tributaries drain a basin of 875?km². The drainage network is characterized as warm-water, low-gradient, and net alkaline. The purpose was to provide synoptic baseline data on water quality and the resident aquatic communities in terms of species richness, stress tolerance, and trophic structure. Overall, we sampled 20 stations on the 2 main branches and 1 on each of the 12 tributaries. We collected 26,375 fishes representing nine families and 54 species/hybrids along with 989 macroinvertebrates from 25 separate taxa. The parameter which defines water quality here is specific conductance which ranges from natural background levels of about 400???S/cm on the minimally impaired Tenmile mainstem to 4,500???S/cm on its SF. Diverse fish and macroinvertebrate communities were documented at levels of specific conductance exceeding 1,000???S/cm, well above the 300???S/cm criterion to protect aquatic life proposed by the US Environmental Protection Agency for streams in the Central Appalachian Region. South Fork fish communities exhibit impairment at levels of specific conductance approaching the maximum observed here.     

Long-term land-use effects on soil invertebrate communities in Southern Piedmont soils,USA

Historically, a large percentage of land area in the Piedmont of the southeastern USA was under intensive agricultural management for the production of cotton. This intensive farming resulted in massive erosion, and general degradation of soil resources until insect pests and poor economic conditions forced large-scale abandonment of farmland around the 1930s. In subsequent decades, there have been four predominant land-uses in the region, and we sampled soil macroinvertebrates from three replicate sites of cultivated fields, grass-dominated fields, loblolly pine stands, and remnant hardwood stands for a period of 2 years, with the objective of examining soil invertebrate community composition in relation to these long-term land-uses. At each site we dug three or four soil pits that were 30 × 30 cm to a depth of 15 cm, and sorted the soil volume by hand for a time not more than 1 person h, collecting all invertebrates ~5 mm in length or larger. We recorded abundance data for all invertebrate taxa collected, and we calculated community indices including diversity, evenness, rank abundance and percent similarity in order to identify patterns of community assemblage within each land-use type. Results suggest that soils in hardwood stands support the most taxonomically diverse macroinvertebrate communities followed by pine stands, pastures, and cultivated fields in order of decreasing diversity. For earthworms, Diplocardia spp. (North American megascolecids) were most abundant in the hardwood stands, but sometimes made up a substantial fraction of the community in other land-uses; whereas lumbricid earthworms (primarily introduced Apporectodea spp.) were most abundant in the cultivated and pasture soils, or showed no consistent habitat preference (native Bimastos spp.). Scarab beetles (larvae and adults) were common in all four systems, but reached the highest densities in cultivated and grass sites. Carabid beetle larvae were collected most often from cultivated soils. Several taxa were collected either exclusively or predominantly from forested sites, including diplopods, chilopods, gastropods, and several taxa of Diptera. These results indicate that long-term soil disturbance and the attendant differences in vegetation structure have profoundly influenced the community composition of invertebrates in Southern Piedmont soils, and that more intense disturbance results in a less diverse invertebrate community composed of a few, frequently non-native, disturbance-tolerant taxa.     

Effects of N placement,carbon distribution and temperature on N2O emissions in clay loam and loamy sand soils

Changes in the profile distribution of soil C stocks for conventional versus no‐tillage can affect N₂O losses. Uncertainty remains whether deep N placement into a wetter layer in humid areas would affect N₂O losses. This study evaluated the effects of soil carbon profile distribution (inverted, normal), depth of nitrogen placement (5 cm, 15 cm), temperature (10, 20 and 30 °C) and soil texture (clay loam, loamy sand) on N₂O emissions from soil cores in a 216‐h incubation after simulated rainfall. N₂O losses were larger from the clay loam than from the loamy sand, and cumulative N₂O emissions from the inverted profile, with greater C levels at depth, were more than those from the profile with more C near the upper surface. Cumulative N₂O losses from the inverted clay loam profile with deep N placement (1.16 mg N per kg dry soil; 0.71% of applied N) on average were almost double those in the loamy sand (0.62 mg N per kg dry soil; 0.42%). The smallest N₂O losses were measured from the profiles with more C close to the upper surface with a shallow placement of N for the clay loam (0.19 mg N per kg dry soil; 0.12%) and loamy sand (0.33 mg N per kg dry soil; 0.23%). An exponential relationship between N₂O fluxes and temperature was measured. We conclude that large N₂O losses may occur under the combination of greater soil C content at deeper layers (ploughed soils) and moist profiles after N application (humid regions). Deep N placement appears to aggravate rather than ameliorate these concerns.     

The influence of disturbance and habitat on the presence of non-native plant species along transport corridors

The impact from transportation corridors on surrounding habitat often reaches far beyond the edge of the corridor. The altered disturbance regime in plant communities along corridor edges and vehicle traffic facilitate the spread and establishment of invasive non-native plant species. We compared the frequency of non-native plant species along highways and railways and the ability of these species to invade grasslands and dense forests along these corridors. We measured the frequency of several non-native plant species along transects 0-150 m from the edge of highways and railways in grasslands and forests, as well as at control sites away from corridors. Both transportation corridors had higher frequency of non-native species than respective control sites. Grasslands had higher frequency of non-native species than forested habitats, but the frequency did not differ between the highways and the railways. The frequency of non-native species in grasslands along highways and railways was higher than at grassland control sites up to 150 m from the corridor edge, whereas the frequency in forested habitats along corridors was higher than at forested control sites up to only 10 m from the corridor edge. There was a significant decrease in the frequency of non-native species with increasing distance from both corridors in the forest, while grasslands showed no significant change in non-native species frequency with distance from corridors. This suggests that corridor edges and grassland habitats act as microhabitats for non-native species and are more prone to invasion than forests, especially if disturbed. Our results emphasize the importance of minimizing the disturbance of adjacent plant communities along highways and railways during construction and maintenance, particularly in grassland habitats and in areas sensitive to additional fragmentation and habitat loss.     

Pollution of ground water by nutrients and fecal coliforms from lakeshore septic tank systems

The fate of wastewater effluents discharged from 17 septic tank disposal systems located near the shores of eight lakes in northeastern and eastern New York State was investigated. Fecal coliforms chloride, conductivity, dissolved 0₂, phosphate and various forms of N in ground water samples were analyzed. Of 46 ground water samples, 23 were found to be highly contaminated and 16 slightly contaminated. Only 7 were not contaminated by the wastewater effluent. Seventeen of the 23 highly contaminated samples were collected within 30.5 m of the discharge point of the septic systems. Eleven of these were collected from ground water less than 122 cm below ground level. Eight of the 16 slightly contaminated samples and 3 of the 7 noncontaminated samples were collected at a distance greater than 30.5 m. The depth to the ground water from ground surface and the distance of the ground water from the discharge point of the sewage system are main factors influencing pattern and severity of ground water contamination. This survey indicated that significant nutrient and fecal coliform contamination of lakeshore ground waters was occurring.