共查询到20条相似文献，搜索用时 15 毫秒
1.
An Assessment of Potential Oil Spill Damage to Salt Marsh Habitats and Fishery Resources in Galveston Bay, Texas 总被引：1，自引：0，他引：1
Lawrence P. Rozas Thomas J. Minello Charles B. Henry 《Marine pollution bulletin》2000,40(12):1148-1160
We sampled nekton, benthic infauna, and sediments in salt marshes of upper Galveston Bay, Texas to examine relationships between habitat use and sediment hydrocarbon concentration. Most marsh sediment samples were contaminated with relatively low concentrations of weathered petroleum hydrocarbons. We found few statistically significant negative relationships between animal density and hydrocarbon concentration (6 of 63 taxa examined using simple linear regression). Hydrocarbon concentration did not contribute significantly to Stepwise Multiple Regression models we used to explore potential relationships between animal densities and environmental parameters; in most cases where hydrocarbon concentration was an important variable in the models, the relationship was positive (i.e., animal densities increased with hydrocarbon concentration). Low hydrocarbon concentrations in sediments of upper Galveston Bay marshes could have contributed to our results either because levels were too low to be toxic or levels were toxic but too low to be detected by most organisms. 相似文献
2.
Zenetos A Hatzianestis J Lantzouni M Simboura M Sklivagou E Arvanitakis G 《Marine pollution bulletin》2004,48(1-2):122-131
The sinking of the tanker Eurobulker in Southern Evoikos gulf (Aegean Sea, Greece) in September 2000 resulted in a spill of 700 tons of crude oil. The environmental impact of the spill was studied by the National Centre for Marine Research. The hydrocarbon concentrations in water, sediment and coastal benthic organisms were measured and the response of the benthic communities to the disturbance caused by the oil spill was studied along the direction to the coast and over three sampling seasons. The most severe and direct effects were evidenced on the muddy benthic communities of the accident site and the stations in the close vicinity sampled shortly after the spill. The effects included reduction of the species richness and community diversity, but the communities reached full recovery 8 months later. The impact of the spill was more indirect and delayed in the coastal stations, where as the hydrocarbon measurements indicated, the pollutants were transported later and induced their effects on the benthic communities 6 months after the accident. 相似文献
3.
4.
McMurdo Station is the United States Antarctic Research Program's (USARP) centre for scientific and logistical support for most of the continent and is the largest settlement in Antarctica. Over 30 years of human presence with shipping, air-transport, scientific, and municipal activities have resulted in severe but localized nearshore marine benthic pollution. This review will summarize the results of 3 years of research which has documented concentrations of chemical contaminants, changes in community patterns, and the toxicity of sediments to invertebrate species and infaunal communities. The primary contaminants are petroleum hydrocarbons in the sediments of Winter Quarters Bay, the site of shipping activities and a former dumpsite. Total hydrocarbon levels in sediments in Winter Quarters Bay were comparable to the most polluted harbours in temperate latitudes. However, a steep gradient of pollution existed: stations less than 1 km away were nearly pristine. Benthic invertebrate communities changed dramatically along this contamination gradient. The results of both field and laboratory bioassay experiments with contaminated sediments found that biological changes observed in benthic communities around McMurdo Station were most likely caused by hydrocarbons, PCBs, and PCTs. A primary goal of polar pollution research is to determine the response and tolerance of Antarctic biota to physical and chemical anthropogenic disturbance, and the mitigation of negative effects. To this end, future work should include continued monitoring of changes in chemical and community patterns, studies of the physiological responses of Antarctic invertebrates to chemical contamination, and further comparisons of anthropogenic and natural disturbances to benthic communities. 相似文献
5.
Phaeocystis blooms are of major importance in the Eastern English Channel, where they significantly contribute to spring organic matter input with chlorophyll concentrations commonly higher than 30 microgl(-1) in the water column. Post-bloom deposition of Phaeocystis derived mucilaginous compounds has been shown to have a major importance on benthic intertidal systems, but resulting mineralization processes and consequences on the macrobenthic compartment remain poorly documented in subtidal areas. In this frame, a study was performed along the French coast of the English Channel to quantify mineralization processes, as well as potential consequences on subtidal sediments, especially their geochemistry and associated macrofaunal communities. Seven stations were studied along a depth gradient during four cruises: before (March), during (April, May) and after (June) the spring bloom. Sediment characteristics and organic carbon content were described, as well as sediment-water fluxes of oxygen and ammonium. Macrofaunal characteristics were also analyzed. Stations were chosen as representative of the various benthic communities present in the area, which are directly linked to the granulometric characteristics of the sediments. To account for the general functioning of the water column, characterized by a coastal flow where higher concentrations of Phaeocystis are generally recorded, similar communities were sampled inshore and offshore, when possible: (i) the Abra alba community located only close to the coast, (ii) the Ophelia borealis community located inshore and offshore, and (iii) the Amphioxus lanceolatus community located inshore and offshore. Generally, low exchange rates of oxygen and ammonium were measured (respectively, in the range 50-150 micromol O2 m(-2)h(-1) and -25 to 35 micromol NH4+ m(-2)h(-1)) between the water column and the muddy-sand to coarse sand permeable sediments, as a consequence of the low organic carbon content due to the high hydrodynamic forcing. As a consequence of organic matter accumulation in surficial sediments probably resulting from Phaeocystis post-bloom deposition, an increase of sediment oxygen demand and ammonium release was clearly evidenced up to 660 micromol O2 m(-2)h(-1) and 205 micromol NH4+ m(-2)h(-1) in May, only in stations located close to the coast (<8 kms), in the A. alba community. Despite those significant biogeochemical changes in surficial sediments, no significant consequence was pointed out on macrofauna, neither in the O. borealis and A. lanceolatus communities, nor in the coastal A. alba community. Most of the temporal variations recorded might be attributed to the common spring population dynamics, but this study highlights the potential use of geochemical parameters as a forewarning signal of benthic disequilibrium. 相似文献
6.
Sediment quality of the lower St. Johns River (LSJR) estuary, Florida was evaluated using synoptic data on benthic community structure, levels of potential stressors (chemical contaminants, ammonia and sulfide), and other basic habitat characteristics (depth, dissolved oxygen, salinity, temperature) collected at seven stations, three times a year from July 2000-July 2002. Un-ionized ammonia and hydrogen sulfide were detected at toxic levels on at least one sampling occasion at four stations. Chemical contamination of sediment at probable bioeffect levels also was observed at four stations. Concentrations of pesticides or other chemical substances typically associated with human activities (e.g., PCBs) were detectable at all stations, though not always present at concentrations likely of causing significant bioeffects. A total of 251 taxa and 9783 individuals were identified and enumerated from the benthic infaunal samples. Polychaete worms and molluscs dominated the benthic fauna at all seven stations. The opportunistic and pollution-tolerant polychaete Streblospio benedicti was the most abundant species overall (from all samples combined), appearing as a dominant at five of the seven stations. Overall, the sites sampled as part of this study indicate a highly stressed benthos resulting from multiple anthropogenic impacts. 相似文献
7.
Threshold response of benthic macrofauna integrity to metal contamination in West Greenland 总被引：2，自引：1，他引：1
Sediment metal chemistry and benthic infauna surveys have been conducted over 33 years following a BACI protocol in relation to submarine tailings deposition (STD) from a lead-zinc mine in a western Greenland fjord system. We found clear predictable changes of benthic fauna composition in response to STD both temporally and spatially. Faunal re-colonization 15 years after mine closure, was slow and the impacted areas were still dominated by opportunistic species, although the most opportunistic ones (e.g. Capitella species) had decreased in importance. Concentration-response relations between sediment lead and faunal indices of benthic community integrity (e.g. the AMBI and DKI indices) indicated a threshold of ca. 200mg/kg, above which deterioration of faunal communities occurred. Above this threshold, diversity decreased dramatically and dominance of sensitive and indifferent species was substituted by tolerant or opportunistic species. Disposal of metal contaminated tailings may have long lasting effects on the biological system. 相似文献
8.
Sbastien Thorin Alain Radureau Eric Feunteun Jean-Claude Lefeuvre 《Continental Shelf Research》2001,21(18-19)
Environmental conditions in terms of river inputs, salt marsh development, shellfish cultures, hydrodynamics and sediment characteristics are very different from the western and the eastern part of the Mont Saint-Michel bay. A large scale study on the spatial structure of the intertidal macrozoobenthic community was then performed at the bay scale in order to determinate how these various conditions may modify the community composition and species density. In terms of density, the community was globally dominated by suspension/deposit filter-feeding bivalves, as well as amphipods in the eastern high levels of the intertidal zone. Several biocoenotic assemblage of the Macoma balthica community were described and large differences in the species composition and density were observed between the eastern and the western sectors of the bay. Total density for all species and recruitment were much higher in the eastern sector than in the west. We discussed about these east–west variations in terms of hydrodynamics, sedimentation processes and trophic conditions. Indeed, the large salt marsh extension and river inputs, as well as the lack of shellfish cultures in the east, may favour high food availability for benthic invertebrates of the area whereas the low river inputs and salt marsh development, the high sedimentation process and the intensification of mussel and oyster cultures in the west may create less favourable environments. 相似文献
9.
Ifigenia Kagalou Georgios Economidis Ioannis Leonardos Constantinos Papaloukas 《Limnologica》2006,36(4):269-278
Macroinvertebrates play a key role in freshwater lentic and lotic ecosystems. The macroinvertebrate benthic community of a shallow Mediterranean lake (Lake Pamvotis, NW Greece) was studied. The benthic assemblage was sampled monthly at five sites during a period of 1 year (Apr. 1998–Mar. 1999). In addition hypolimnetic water quality variables were monitored over the same period at each site.
The aim of the study was (a) to describe the intra-annual and spatial variability in benthic communities, (b) to relate possible community changes to environmental conditions and (c) to evaluate the responses of the lake's ecological status on community indices.
The benthic fauna of Lake Pamvotis was found to be very limited with a total of 10 species belonging to five taxonomic groups. The oligochaete community comprised 80% of the total benthic fauna with Potamothrix bavaricus as a new record for the Lake Pamvotis and Potamothrix hammoniensis, being the dominant benthic species represented more than 61% of the total benthic fauna. Chironomus plumosus was the most abundant chironomid species contributing with about 6% of the total benthic fauna, and Chaoborus flavicans with 19% was the important dipteran. Almost all benthic species showed the same intra-annual seasonal pattern, with peak population densities during spring and early summer except P. hammoniensis which predominated during the whole sampling period. Dissolved oxygen and temperature seemed to be the main environmental factors affecting community indices.
Benthic communities are affected by human disturbances in Lake Pamvotis shifting their composition to more tolerant taxa, reflecting also the eutrophic to hypertophic character of the lake. 相似文献
10.
A project to deepen shipping and entrance channels in Charleston Harbor was conducted from 1999 to 2002. This generated approximately 22 million cubic yards of sediment for offshore disposal. Assessments of biological and physical conditions in the Charleston Ocean Dredged Material Disposal Site and surrounding areas were conducted prior to deepening (1993-94), and partway through the disposal period (2000). Results from the 2000 survey are presented and compared to the baseline survey. The study area was composed of the disposal zone and surrounding areas and divided into 20 one square mile strata. Within each stratum, benthic grab samples were collected from ten random sites for analysis of sediment composition and contaminants and macrobenthic assemblages. No contaminant levels were above effects range low levels. Results revealed that sediments in the western strata had significantly higher silt/clay content in the 2000 survey when compared to baseline sediments, while sediments east of the disposal zone were similar to baseline. Analyses were performed on a subset of the benthic data that compared baseline to 2000 conditions in western and eastern strata. The benthic communities in western strata were altered following disposal operations. The benthic community east of the disposal area was not different from baseline conditions. These alterations in the benthic community were attributed to changes in bottom habitat characteristics rather than pollution effects. 相似文献
11.
A benthic habitat along the coast of McMurdo Station in the Ross Sea, Antarctica is enriched by sewage from the station and altered by hydrocarbons and heavy metals in an adjacent historic dumpsite. We report on 10 years of change in the benthic communities from 1988 to 1998 and compare enrichment effects at Australia's Casey Station, East Antarctica. Despite being 14 km apart, reference communities upcurrent and downcurrent of McMurdo Station remained closely similar over time, dominated in all years by a tube building polychaete, Spiophanes tcherniae. The community bordering McMurdo Station was generally a third as abundant as communities at the reference sites over the decade of sampling, although diversity was as high or higher, except in the most contaminated areas. In 1992, organic enrichment of the outfall community intensified and within the year, the opportunistic polychaetes Aphelochaeta sp., Ophryotrocha notialis, Capitella perarmata, and Leitoscoloplos kerguelensis became dominant. Since 1996, two of the three enriched communities have increased in resemblance to the reference communities. Given the observed responsiveness of the benthos to the outfall so far, further changes are anticipated within the year following implementation of sewage treatment in 2003. Organic enrichment by McMurdo Station has had a greater impact on benthic community structure than at Australia's Casey Station. 相似文献
12.
13.
S.G. Cheung C.Y.S. Chan B.H.K. Po A.L. Li J.Y.S. Leung J.W. Qiu P.O. Ang V. Thiyagarajan P.K.S. Shin J.M.Y. Chiu 《Marine pollution bulletin》2014
Biofilms on submerged surfaces are important in determining larval settlement of most marine benthic invertebrates. We investigated if exposure of biofilms to hypoxia would alter the larval settlement pattern and result in a shift in benthic invertebrate community structure in the field. Biofilms were first exposed to hypoxia or normoxia in laboratory microcosms for 7 days, and then deployed in the field for another 7 days to allow for larval settlement and recruitment to occur. Using terminal-restriction fragment length polymorphism of the 16S rRNA gene, this study showed that hypoxia altered the biofilm bacterial community composition, and the difference between the hypoxic and normoxic treatments increased with the time of exposure period. This study also demonstrated significantly different benthic invertebrate community structures as a result of biofilm exposure to hypoxia and that the hypoxic and normoxic treatments were dominated by Hydroides sp. and Folliculina sp., respectively. 相似文献
14.
Xavier Le Pichon Toshimishi Iiyama Jacques Boulgue Jacques Charvet Michel Faure Kenichi Kano Siegfried Lallemant Hakuyu Okada Claude Rangin Asahiko Taira Tetsuro Urabe Seiya Uyeda 《Earth and Planetary Science Letters》1987,83(1-4)
Eight submersible dives between 3000 and 4200 m water depth were made off southern Japan in the eastern Nankai subduction zone. Benthic communities associated with chemosynthetic processes were discovered along the 800 m wide active tectonic zone, at the toe of the accretionary prism. A benthic community was also discovered along a zone of active compression, at the foot of Zenisu Ridge, 30 km south of Nankai Trough. Temperature measurements within the sediments below the benthic communities confirm that upward motion of interstitial water occurs there. Studies of water samples indicate advection of methane and light hydrocarbons. Specimens of the benthic community have been shown to have included in their shells carbonate resulting from methane consumption. Thus the benthic communities are related to overpressure-driven fluid advection along tectonic zones with active surface deformation. A 300 m high active scarp at the toe of the accretionary prism is related to relative motion in a 280° direction which is close to the 305° average direction of subduction in this area. The dives establish further that compressive deformation is presently occurring at the foot of Zenisu Ridge. The previous interpretation of the Zenisu Ridge as a zone of recent north-south intraplate shortening, 40 km south of the Nankai Trench, is confirmed. We conclude that tectonic evolution might well lead to future detachment of the Zenisu Ridge and overthrusting of this large piece of oceanic crust over the continental margin. Such a process might be an efficient one to emplace ophiolites over continents. 相似文献
15.
Michotey V Guasco S Boeuf D Morezzi N Durieux B Charpy L Bonin P 《Marine pollution bulletin》2012,65(10-12):525-537
Spatio-temporal variability of prokaryotic water column communities inside and outside a Polynesian tropical lagoon subjected to pearl oysters farming was assessed in terms of abundance by quantitative PCR and diversity by DGGE. Communities and operational taxonomic units (OTUs) were analysed according to dry/rainy seasons and free-living/particle-attached state. Bacterial density was higher in the lagoon compared to ocean and a seasonal trend was observed. No influence of the localisation within lagoon or of the planktonic/attached states was noticed on bacterial abundance and diversity. The OTUs belonged to Cyanobacteria, to heterotrophic groups in Proteobacteria and Flavobacteria. Archaeal abundance showed seasonal tendency and particle-prevalence, but no effect of lagoon or oceanic location was observed. Lagoon and oceanic archaeal diversity were different and Euryarchaeota (MG-II, MBG, and Halobacteria) were detected. During the dry season, planktonic and particle-associated community differed, whereas at rainy season, both communities were similar and included members usually associated with coral. 相似文献
16.
Organic mercury such as methylmercury is not only one of the most toxic substances found in coastal ecosystems but also has high trophic transfer efficiency. In this study, we examined implications of chronically altered benthic macroinfaunal assemblages for organic mercury trophic availability (based on organic mercury intracellular partitioning) to their predators in the Arthur Kill-AK (New York, USA). Despite low species diversity, both density and biomass of benthic macroinvertebrates in AK were significantly higher than those at the reference site. Disproportionately high biomass of benthic macroinvertebrates (mostly polychaetes) in the northern AK resulted in a more than twofold increase (‘ecological enrichment’) in the trophically available organic mercury pool. These results suggest that altered benthic macroinfaunal community structure in AK may play an important role in organic mercury trophic availability at the base of benthic food webs and potentially in mercury biogeochemical cycling in this severely urbanized coastal ecosystem. 相似文献
17.
三峡水库举世瞩目,是长江保护与治理的关键性枢纽工程,水库自2003年蓄水运行后库区水沙条件均发生了显著改变,对库区水生态环境产生了深远影响。本文系统综述了三峡水库蓄水运行后库区的水流动力特性和泥沙淤积特性,总结了蓄水后水库的新水沙运动情况;从水库蓄水运行后水质参数特征,营养物质、重金属和典型有毒有机污染物的赋存特征等方面,分析了三峡水库库区新水沙变化条件下的水环境响应特征;基于水库蓄水前后浮游植物、底栖动物等重点生物群落的现存量和群落特征变化规律,探索了三峡水库新水沙变化条件下库区的水生态响应特征;最后对未来三峡水库运行下的水生态环境效应研究提出展望,本文可为三峡水库水生态环境保护科学研究和管理提供新的认识和决策参考。 相似文献
18.
A two-year study was conducted in the vicinity of a harbour in sub-tropical Hong Kong, to examine the progress of improvement in sediment quality and recovery of macrobenthic community upon cessation of organic pollution caused by sewage discharge. Median sediment particle diameter (Mdphi) and levels of total organic carbon (TOC), total Kjeldahl nitrogen (TKN), ammonia-nitrogen (NH(3)-N) and total phosphorus (TP), as well as macrobenthic species composition and abundance were determined bi-monthly at three inside-harbour and two outside-harbour locations. At the two inside-harbour locations, significantly higher levels of TOC, TKN, NH(3)-N and TP in sediments were observed than the outside-harbour locations. However, no significant temporal change of nutrient levels was detected at all sampling locations during the two-year study, except a significant decrease in TKN and NH(3)-N levels at one outside-harbour location and a decline in NH(3)-N content at another outside-harbour location. Spatially, the highest in mean total species number, individual number, species diversity H' and lowest evenness J was found at one outside-harbour location, whereas the other four locations had relatively similar values. H' was negatively correlated with TOC, TKN, NH(3)-N and TP content in sediments while J was positively correlated with MDphi. Across the study period, the patterns of macrobenthic community were significantly different among all samplings and that the spatial difference of benthic community was best correlated with MDphi, TOC, TKN and water depth. A weak sign of recovery in macrobenthic community structure was detected at inside-harbour locations, with replacement of opportunistic by ubiquitous species over the two-year study. The slow recovery of macrobenthic community was related to sediment characteristics. Results of a larval settlement bioassay using the polychaete Capitella sp. I also demonstrated that the inside-harbour sediments were still unfavourable for colonization and larval settlement of species sensitive to pollution. The slow biodegradation of the organic pollutants and continuous presence of heavy metals in the sediment may hinder settlement and colonization of benthic animals. However, increases of H' and J were observed in a longer time scale when comparing the present data with those obtained four years ago. This suggested that a detectable recovery of benthic community in the harbour may take at least three years and a complete recovery may even take longer duration. 相似文献
19.
Among the most important impacts of trawling is the disturbance of the benthic environment as well as the mortality of the larger benthic organisms, which is caused by the passage of the fishing gear. Meiofauna, which are among the smallest benthic organisms, may be more resistant to disturbance by trawling since they are likely to be re-suspended rather than killed by trawls. Their short generation times allow populations to withstand elevated mortality. In this study, we determined the effect of trawling disturbance, season and sediment type on the structure of meiofaunal communities in a commercial fishing ground in Thermaikos Gulf, north Aegean Sea, Greece. The trawling season is limited to 8 months between October and May. A grid of five nearshore stations was chosen along a north–south productivity gradient and an additional offshore station was included as a reference point. Sediment chemistry and meiofaunal community structure were studied before the trawling season started, as well as 1 and 4 months after the initiation of the fishing period. Results showed that there were no short term (30 days) trawling impacts on meiofauna in terms of abundance and community structure but that there were recognizable effects on the community structure of nematodes and the abundance of polychaetes. In contrast, most meiofaunal taxa displayed significant seasonal variability, 4 months after the initiation of the fishing period; however, other closely related factors such as temperature, sediment particle size and primary productivity are more likely to be responsible for the observed patterns. 相似文献
20.
Benthic faunal structure and hydrocarbon concentrations in sediments were examined annually for 10 years (1989-1998) in Port Valdez, Alaska, where a near-bottom permitted discharge of treated tanker ballast waters containing residual petroleum has occurred since 1977. Measured concentrations of hydrocarbons in sediments near the discharge showed detectable increases in concentration, but on only one occasion were these increases either to levels exceeding ecotoxicological thresholds (Effects-Range Low, ER-L) or associated with alterations in the benthic community. Changes in faunal structure indicating disturbance were observed at one station near the discharge from 1995 to 1997 and were apparent as increased numbers of opportunistic taxa and anomalous trends in abundance and diversity. Minimum-effect (ME) hypotheses provided evidence of negligible to small effects on benthic infauna from disposal of treated ballast water. ME hypotheses have the potential to assist both researchers and managers by providing a tool to relate scientific results to ecological importance and decision criteria. 相似文献