首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 875 毫秒
1.
With the passage of the Beaches Environmental Assessment and Coastal Health (BEACH) Act in 2000, coastal states were mandated to assess and sample coastal recreational waters for bacterial ambient water quality parameters. The assessment of beach sites required the application of federal guidelines and a tiered approach to delineating the beaches. Eighty-seven beach sites in Oregon were evaluated and ranked by use, available information, pollution threats, sanitary survey and monitoring data results, exposure considerations, and economic/development factors. This ranking resulted in 19 high priority beaches (tier 1), five medium priority beaches (tier 2), 23 low priority beaches, and 40 beaches with a rank of none in Oregon.  相似文献   

2.
Mussels, Mytilus trossulus (average shell length 43+/-0.8 mm), were sampled from a beach in Alaska that received untreated sewage for several years, a second beach adjacent to a secondary wastewater outfall, and two nearby reference beaches. Survival time in air, byssal thread production rate, and prevalence of trematode parasites were determined for each group. Tolerances to aerial exposure was significantly lower (P<0.05) at both sewage outfall sites than at the reference sites. Mussels exposed to untreated sewage produced fewer byssal threads and had a significantly higher prevalence of encysted trematodes than mussels from the other beaches, including the secondary wastewater site. Survival in air, byssal thread production, and trematode prevalence in mussels may be useful indicators in evaluating the longterm health of beaches exposed to sewage.  相似文献   

3.
Plastic pellets found stranded on beaches are hydrophobic organic materials and thus, they are a favourable medium for persistent organic pollutants to absorb to. In the present study, plastic pellets are used to determine the diffuse pollution of selected Greek beaches. Samples of pellets were taken from these beaches and were analyzed for PCBs, DDTs, HCHs, and PAHs. The observed differences among pellets from various sampling sites are related to the pollution occurring at each site. Plastic pellets collected in Saronikos Gulf beaches demonstrate much higher pollutant loading than the ones collected in a remote island or close to an agricultural area. Based on data collected in this study and the International Pellet Watch program, pollution in Saronikos Gulf, Greece, is comparable to other heavily industrialized places of the world. The present study demonstrates the potential of pellet watch to be utilized as a detailed-scale monitoring tool within a single country.  相似文献   

4.
We discuss the use of the nematode to copepod ratio in relation to determining the extent of metals impact using the Cha?aral area of northern Chile, where the dumping of copper mine tailings has taken place for many years, as an example. Data were collected from 12 beaches in the area on eight occasions between January 1997 and October 1998. We find that the ratio is not a good predictor of pollution due to the generally low densities of meiofauna on impacted beaches and the absence of harpacticoid copepods from those beaches. We suggest that in the case of metal pollution the mean number of Harpacticoida per site may be a better indicator of impact stress. We rule out the use of the nematode to copepod ratio as an indicator in biomonitoring studies where metal enrichment is thought to occur.  相似文献   

5.
Many studies have quantified debris collected on beaches around the world. Only a few of those studies have been conducted in the United States, and they are largely limited to semi-quantitative efforts performed as part of volunteer clean-up activities. This study quantifies the distribution and composition of beach debris by sampling 43 stratified random sites on the Orange County, California coast, from August to September 1998. We estimated that approximately 106 million items, weighing 12 metric tons, occur on Orange County beaches. The most abundant items were pre-production plastic pellets, foamed plastics, and hard plastics. Debris density on the remote rocky shoreline was greater than that on high-use sandy beaches for most debris items. This finding partially reflects the periodic clean-up of high-use beaches by local municipalities, and also indicates that a high percentage of the observed debris was transported to the site from waterborne sources.  相似文献   

6.
Our aim was to examine the health effects on bathers from exposure to recreational seawater on three beaches with different microbiology quality and bather density through a cohort study. An initial questionnaire and a 10 day follow up were used. Univariate and backward logistic regression analyses were used to asses the risk of developing symptoms or diseases among the bathers. In total, 3805 bathers were included in the study and 149 samples were collected from the three beaches. Despite all the beaches being characterized of high quality the levels of bacterial indicators differed among them. Health effects among bathers were not associated with bacterial indicators. A statistically significant increased risk for symptoms related to respiratory illness, gastroenteritis, medical consultation and use of medication was observed among bathers at the higher bather density beaches. Beach bather numbers should always be taken into account when considering a risk assessment approach.  相似文献   

7.
An increasingly common method to restore eroding beaches is nourishment, a process by which lost sand is replaced with terrestrial or offshore sediments to widen beaches. The southeastern Florida coastline contains shore-parallel coral reef communities adjacent to eroding beaches. Scleractinian corals and other reef-associated organisms are known to demonstrate sensitivity to elevated sedimentation levels. Sediment traps were used to examine spatio-temporal sedimentation patterns and assess the effects of nourishment (dredge and fill) activities. Several environmental variables correlated with among-site spatial variability of sediment parameters. Intra-annual variability correlated with wind velocity and direction. Nourishment activities showed localized effects, with sites in close proximity to dredging areas exhibiting significantly higher collection rates and lower percent fines than control sites. A regional increase in sedimentation occurred while nourishment activities were ongoing. Due to concurrent impacts of hurricanes, only one during-construction sampling interval revealed substantially higher collection rates relative to corresponding pre-construction sampling intervals.  相似文献   

8.
Environmental variables and their association with faecal coliform and streptococci densities were investigated at a number of Sydney's metropolitan beaches. High variability in faecal coliform and faecal streptococci densities was observed at most beaches. The ability of the various models to explain the observed variation in faecal coliform or streptococci levels was relatively low, although they did provide an insight into the more influential environmental factors involved. Rainfall has the single most important effect on faecal coliform and streptococci densities at Sydney beaches. Whether this is due to increased stormwater runoff at the beaches, increased discharge through the outfalls (both the deepwater ocean outfalls and the few remaining shoreline outfalls), or a combination of both is unclear and is likely to depend on the individual beach being considered. Elevated levels of faecal coliforms and streptococci are still occasionally observed at some beaches, but these levels are usually not as high nor as frequent as they were prior to commissioning of the deepwater outfalls. The significant associations of current and plume entrapment with faecal coliform and streptococci densities at some Sydney beaches suggest that under certain conditions, effluent from the deepwater ocean outfalls can still influence faecal coliform and streptococci densities at these beaches.  相似文献   

9.
Concentrations of polychlorinated biphenyls (PCBs) in beached resin pellets were examined to reveal variability between individual particles and differences among beaches. Fifty-five resin pellets from a beach in Tokyo were individually analyzed for PCBs, and showed concentrations ranging from <28 to 2,300 ng/g. This indicates that concentrations are highly variable between particles. Among several characters, discoloration (e.g., yellowing) had a positive relationship with PCB concentration: discolored pellets contained more PCBs than others on most of the beaches sampled. Given the color-selective ingestion of food by some organisms, this may be ecotoxicologically important. Measurements of samples from 47 beaches in Japan showed regional differences in PCB concentrations in resin pellets consistent with those in mussels. Sporadic high concentrations of PCBs were also found in pellets from remote islands, suggesting that resin pellets could be the dominant route of exposure to the contaminants at remote sites. The similarity of PCB concentrations between resin pellets and mussels suggests a potential use of resin pellets to monitor pollution in seawater.  相似文献   

10.
Amounts of tar stranded on Florida beaches were determined periodically over one year (September 1979–October 1980). Results show that tar fouling of southeast Florida beaches is an order of magnitude greater than the rest of the state. This may result from the extensive ship traffic in the Straits of Florida. There is no evidence that any Florida beaches received increased amounts of tar as a result of the 1979 Ixtoc-1 blowout in the southern Bay of Campeche. There is also no evidence that the amounts of tar on southeast Florida beaches have increased over amounts measured in API studies conducted in 1958 and 1971.  相似文献   

11.
Empirical evaluation of microtremor H/V spectral ratio   总被引：6，自引：2，他引：4  
The objective of this work is to perform a purely empirical assessment of the actual capabilities of the horizontal-to-vertical (H/V) spectral ratio technique to provide reliable and relevant information concerning site conditions and/or site amplification. This objective has been tackled through the homogeneous (re)processing of a large volume of earthquakes and ambient noise data recorded by different research teams in more than 200 sites located mainly in Europe, but also in the Caribbean and in Tehran. The original recordings were first gathered in a specific database with information on both the sites and recorded events. Then, for all sites close to an instrumented reference, average site-to-reference spectral ratios (“spectral ratio method” (SSR)) were derived in a homogeneous way (window selection, smoothing, signal-to-noise ratio threshold, averaging), as well as H/V ratios (“HVSRE–RF”) on earthquake recordings. H/V ratios were also obtained from noise recordings at each site (either specific measurements, or extracted from pre- or post-event noise windows). The spectral curves resulting from these three techniques were estimated reliable for a subset of 104 sites, and were thus compared in terms of fundamental frequency, amplitude and amplification bandwidth, exhibiting agreements and disagreements, for which interpretations are looked for in relation with characteristics of site conditions. The first important result consists in the very good agreement between fundamental frequencies obtained with either technique, observed for 81% of the analyzed sites. A significant part of the disagreements correspond to thick, low frequency, continental sites where natural noise level is often very low and H/V noise ratios do not exhibit any clear peak. The second important result is the absence of correlation between H/V peak amplitude and the actual site amplification measured on site-to-reference spectral ratios. There are, however, two statistically significant results about the amplitude of the H/V curve: the peak amplitude may be considered as a lower bound estimate of the actual amplification indicated by SSR (it is smaller for 79% of the 104 investigated sites), and, from another point of view, the difference in amplitude exhibits a questioning correlation with the geometrical characteristics of the sediment/basement interface: large SSR/HV differences might thus help to detect the existence of significant 2D or 3D effects.  相似文献   

12.
Six sites (two sites for each of rocky shores, sandy beaches, and fishing ports) in northern Taiwan were selected to investigate the amount and density of marine debris in each of the four seasons and after spring and neap tides from 2012 to 2013. The results indicate that marine debris was higher on rocky shores than sandy beaches and fishing ports. There is no significant difference between season and tide. The dominant debris was plastic-type, followed by polystyrene. The majority of debris originated from recreational activities, followed from ocean/waterway activities. The results suggest that the following actions are needed: (1) continue and reinforce the plastic-limit policy; (2) increase the cleaning frequency at rocky shores; (3) promote marine environmental education, with a goal of debris-free coasts; (4) recycle fishing gear and to turn that gear into energy; and (5) coordinate between agencies to establish a mechanism to monitor debris.  相似文献   

13.
The distribution and abundance of marine litter on 26 beaches along the Sea of Japan were investigated from September to November 2000. The mean concentration of stranded litter in Japan and Russia was 2144 and 1344 g/100 m(2), respectively. The mean number of pieces of stranded litter in Japan and Russia was 341 and 20.7/100 m(2), respectively. The most abundant type of stranded litter was plastic, which accounted for 40-80 % of the total items in terms of weight and number. The mean concentration of buried litter in Japan and Russia was 9.03 and 2.70 g/m(2), respectively. The total weight ratio of buried litter to stranded litter in the samples was 0.65, suggesting the significance of buried litter when evaluating the status of litter on beaches. Resin pellets were found on 12 Japanese beaches, but on none of the Russian beaches.  相似文献   

14.
This survey was part of a Binational Program (Mexico-United States) in microbiological water quality, with a goal to assess the shoreline bacteriological water quality from Tijuana to Ensenada, Mexico. Samples were collected at 29 sites (19 beaches and 10 outfalls), from the United States border to Punta Banda, Baja California, during summer (1998) and winter (1999). Total coliforms, fecal coliforms and enterococci were used as bacterial indicators. Standard methods were used for total and fecal coliforms, while the Enterolert quick method (IDEXX) was used for the enterococci. Compared with outfalls, the beaches exceeded water quality standards by a small percent, 25.3% in summer and 17% in winter. For outfalls, the percentage of shoreline that exceeded bacterial indicator thresholds had a minor value in summer (32.7%) than in winter (50%). Sites near wastewater discharges had the lowest quality and did not meet the microbiological water quality criteria for recreational use.  相似文献   

15.
Sediment samples were collected from sandy beaches at a variety of sites in the southern Galápagos Archipelago to assess levels of hydrocarbon contamination following the wreck of the oil tanker Jessica. Hydrocarbon levels in sediments were generally very low by international standards ranging between 0.4 and 48.9 ppm, with contamination attributable to the Jessica only detected at three sites Santa Fe, Playa Estación (Puerto Ayora, Santa Cruz) and Long Beach (Isabela). There was evidence of residual hydrocarbon contamination from sources other than the wreck of the Jessica.  相似文献   

16.
Characteristics of drift and beaching of floating marine litter in the Japan Sea are examined numerically using the reanalysis data of the Japan Sea Forecasting System of Kyushu University. The residence time of model marine litter deployed uniformly over the surface of the Japan Sea strongly depends on the buoyancy ratio. However, almost all litter beaches or flows out through straits within 3 years. Experiments with inputs of litter imposed at large cities and the Tsushima Straits as well as river basins of the Japan Sea exhibit a good agreement with beach surveys with regard to country ratios of beached litter along the Japanese coast in cases of lighters. In a case of lighter, almost all lighters originating from Japan beach along the Japanese coast, while almost all lighters originating from a country surrounding the Japan Sea except Japan beach along the coast of that country and the Japanese coast.  相似文献   

17.
The beetle Phaleria maculata is a common inhabitant of the upper intertidal fringe of Chilean beaches. Anthropogenic intervention in coastal areas has increased intensely, leading to changes in the flora and fauna of sandy beaches. To examine the impact of human activities on P. maculata, we studied several beaches along the northern Chilean coast. Beaches were characterized based on morphodynamics and the level of intervention, leading to the estimation of an “Urbanization Index” based on various indicators. The analysis showed a significant inverse correlation between the rate of urbanization and night sky quality. Larval and adult beetles were almost absent on beaches with high levels of urbanization. The results of simple and multiple correlations based on nMDS ordination showed an inverse relationship between increases in urbanization and the abundance of beetles. Because darkling beetles are very sensitive to human interventions on sandy beaches, we suggest that they are ideal indicator organisms for the health of these environments.  相似文献   

18.
Oil stranded as a result of the 1989 Exxon Valdez spill has persisted for >10 years at study sites on Gulf of Alaska shores distant from the spill's origin. These sites were contaminated by "oil mousse", which persists in these settings due to armoring of underlying sediments and their included oil beneath boulders. The boulder-armored beaches that we resampled in 1999 showed continued contamination by subsurface oil, despite their exposure to moderate to high wave energies. Significant declines in surface oil cover occurred at all study sites. In contrast, mousse has persisted under boulders in amounts similar to what was present in 1994 and probably in 1989. Especially striking is the general lack of weathering of this subsurface oil over the last decade. Oil at five of the six armored-beach sites 10 years after the spill is compositionally similar to 11-day old Exxon Valdez oil. Analysis of movements in the boulder-armor that covers the study beaches reveals that only minor shifts have occurred since 1994, suggesting that over the last five, and probably over the last 10 years, boulder-armors have remained largely unmoved at the study sites. These findings emphasize the importance of particular geomorphic parameters in determining stranded oil persistence. Surface armoring, combined with stranding of oil mousse, results in the unexpectedly lengthy persistence of only lightly to moderately weathered oil within otherwise high-energy wave environments.  相似文献   

19.
Tar balls, according to their densities, the prevailing temperature and their degree of weathering, are observed as floating, sinking, or are washed onto the beaches in the marine environment. To characterize the differences between floating and sunken tar balls, samples were analysed by IR, H-nmr, GC and GC/MS techniques. Hexane, benzene and methanol solubilities as well as densities were measured. The degree of weathering of the tar balls was investigated in terms of the losses of n-paraffinic/aromatic hydrocarbons. The ratio of paraffinic/aromatic hydrocarbon concentrations was calculated by IR and H-nmr whereas pristane/phytane ratios were estimated from GC measurements. The comparison of some high molecular weight, but minor, components between the major n-paraffins was obtained from GC/MS measurements.  相似文献   

20.
Water samples from 26 Oregon beaches were analyzed for Escherichia coli (E. coli) and enterococci concentrations by the Oregon Department of Human Services (ODHS) Public Health Laboratory. Nine Oregon beaches exceeded US Environmental Protection Agency's (USEPA) single sample maximum density of 104 enterococci colony forming units (cfu) per 100 mL with levels ranging from 121 to 4325 most probable number (MPN)/100 milliliters (mL). Otter Rock at South Cove had the highest enterococci concentration at 4352 MPN/100 mL. The results from two Oregon beaches exceeded Oregon Department of Environmental Quality's (ODEQ) estuarine E. coli standard of 406 organisms/100 mL. Otter Rock at South Cove had the highest E. coli concentration at 1850 MPN/100 mL while Road's End had an E. coli density of 771 MPN/100 mL. Results of this study suggest that adopting USEPA's marine enterococci standard in lieu of the ODEQ's estuarine standard will lead to increased Oregon beach water standard failures.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号