Community Tolerance Comparison As A New and Sensitive Ecotoxicological Tool

The demonstration of an increased tolerance to a pollutant is direct evidence that this pollutant has presented a selection pressure upon a population or community. Recently, pollution-induced community tolerance (PICT) has been applied to the benthic community in a metal-enriched estuary to establish causal linkage between observed changes in community structure and composition and the presence of copper. This paper describes the rationale and methodology behind applying PICT to the marine benthic environment, and shows it to be a sensitive ecotoxicological tool. It also presents a case study, demonstrating how a PICT investigation has aided the interpretation of changes in a benthic community, establishing a causal linkage between these changes in the community and the presence of a specific pollutant.     

土壤微生物污染诱导群落耐性研究进展

污染诱导群落耐性(PICT)是指生物群落为了在污染环境中继续生存,通过生理生化与遗传特征的改变或以耐性类群生物代替敏感类群,从而使整个群落产生耐性.目前人们已将PICT作为一项指标,从群落耐性方面来评价污染生态学的效应.目前PICT研究已涵盖了水生生物、陆地植物、微生物等,其中土壤微生物是PICT研究的重要群落对象.对土壤微生物群落PICT的研究始于上世纪90年代,并已在多方面取得进展,包括在研究方法上的一些突破和改进.在PICT产生和变化机理等方面也有新发现,如发现了土壤微生物群落PICT与污染物浓度存在较好的正相关关系,并且污染物能够引起土壤微生物群落对其他污染物的共耐性等.在PICT影响因素研究方面发现不仅环境因素会影响PICT的形成,而且检测方法也会影响对PICT的判断.论文较为全面地综述了国际上针对土壤微生物群落PICT的研究进展,包括PICT的概念、研究方法、污染物影响PICT的内在机制及影响PICT的关键因素等,最后提出了研究展望.     

Antibiotika als Umweltkontaminanten — Effekte auf Bodenbakterien

Goal and scope

Among the human and veterinary pharmaceuticals, antibiotics form an important group. Recent research addressed the environmental ‘side effects’ of antibiotics. Evidence for environmental effects of antibiotics has for example been found for the respiratory activity of soil microorganisms. In the present contribution, results of studies on the ecotoxicology of antibiotics that are based on the utilization of carbon substrates in so-called Biolog plates are summarized.

Methods, Results and Conclusions

The method of pollution-induced community tolerance (PICT) takes centre stage. PICT is based on the changes in community composition of environmental communities brought about by a toxicant, which lead to an overall increase in community tolerance to this toxicant. The suitability of such an increase in community tolerance as ecotoxicological endpoint had been the subject of several experiments. It was shown that effect testing of antibiotics requires supplementation of the communities with nutrients, and that the PICT method reveals antibiotic effects with a high specificity. In an application of PICT, effects of three classes of antibacterial compounds were investigated. Dose-response relationships were obtained for all substances, and effect concentrations were partly in the range of expected environmental concentrations. The possible risks of antibiotic use for an increase in the occurrence of antibiotic resistance genes in the environment are also touched upon, including the extent of natural resistance.

Outlook

Due to its specificity, the PICT method has shown to be a suitable ecotoxicological assay. Due to possible effects of tetracyclines on the structure of the soil microbial community, it is advised to use veterinary antibiotics with caution. The risks of an increase in the occurrence of antibiotic resistance in the environment should be investigated in more detail.     

Mediterranean octocorallian communities and the abiotic environment

Octocorallian communities (Coelenterata: Anthozoa) were investigated in 40 underwater stations near Banyuls-sur-Mer (France), as representatives of Mediterranean benthic fauna. The stations, with depths ranging from 0.3 to 40 m, were all sampled by means of SCUBA-diving. Along with a faunistic inventory, the main abiotic properties of each station were examined, such as irradiance, temperature, water movement, slope and presence of sediment. By means of cluster analysis and factor analysis, the main properties of which are briefly outlined in this paper, the existence of 5 separate communities is demonstrated. Two major abiotic factors emerge from this study, viz. submarine daylight and the presence or absence of sediment. Although community structures are found to be correlated with the physical environment, no causal relationships have been established. It is suggested that the tolerance of larval and young adult stages play an important role in this respect.     

江苏省不同营养状况湖泊底栖动物群落结构与多样性比较

为了解江苏省湖泊底栖动物群落结构和多样性并研究其对水环境质量变化的响应,于2012年春秋两季对江苏省16个湖泊51个采样点湖泊底栖动物群落结构与多样性以及湖泊综合营养状态指数进行调查,分析水质指标与底栖动物指数间Pearson相关关系。结果表明,江苏省16个湖泊营养状态指数范围为35.5~66.4,其中约81.2%的湖泊处于轻度-中度富营养状态,表明水质从好到中度污染;湖泊底栖动物优势种为寡毛类的霍甫水丝蚓(Limnodrilus hoffmeisteri),优势度为13.0%;香浓多样性指数(Shannon-Wiener diversity index)范围为0.00~2.20,级别范围由极贫乏到较丰富状态,表明水质污染程度从重度到轻度污染。从全省尺度看,水质评价结果与生物学(香浓多样性指数、Pielou均匀度指数和Biotic Index(BI)指数)评价结果存在一定差异。与历史数据相比,江苏省湖泊底栖动物清洁敏感物种减少甚至消失,总体群落结构趋于小型化。16个湖泊水体总氮和总磷与底栖动物密度呈显著负相关,而综合营养状态指数与底栖动物指数(香浓多样性指数、Pielou均匀度指数和BI指数)间关系不显著。上述研究结果表明综合营养状态指数无法完全客观反映湖泊水生态健康状况,因此需要综合水质、水文、水生生物、生境状况等因素发展新的评价指标体系。     

Medium-term impacts of hydraulic clam dredgers on a macrobenthic community of the Adriatic Sea (Italy)

Hydraulic dredging targeting the bivalve Chamelea gallina in the northern and central Adriatic Sea has been taking place for over 30 years. In the period 2000–2001, 73 commercial dredgers harvested the resource within the sandy coastal area of the Ancona Maritime District (central Adriatic Sea). Despite this, no study aimed at investigating the impact of the fishery on the macrobenthic community of the area has ever been carried out. Sampling was done at 6 monthly intervals in an attempt to relate the impact of hydraulic dredging to different levels of fishing intensity. Data regarding two depth strata (4–6; 7–10 m) were analysed separately by means of permutational multivariate analysis of variance. The results revealed an overall condition of moderate disturbance within the benthic community, especially so within the 4–6 m depth stratum. The response of the benthic community to varying intensities of fishing activity was rapid, occurring within 6 months. Differences in the response of benthic community to differing intensities of fishing activity were found between the two depth strata considered. Significant differences in multivariate location of the benthic community were revealed between the three disturbance levels in both depth strata. Differences in multivariate dispersion were detected above a threshold level of fishing intensity, only within the shallow community. Differences were found between depth strata relating to species diversity and evenness, with significant differences between levels of fishing intensity being evident only within the 4–6 m depth stratum. The results emphasised that, even in a benthic community that is typical of a moderately disturbed environment, the effects of fishing on community structure were still discernible over and above the natural variation.     

The cost of tolerance: sensitivity of stream benthic communities to UV-B and metals.

The ability to tolerate disturbance is a defense strategy that minimizes the effects of damage to fitness and is essential for sustainability of populations, communities, and ecosystems. Despite the apparent benefits of tolerance, there may be an associated cost that results in a deficiency of a system to respond to additional disturbances. Aquatic ecosystems are often exposed to a variety of natural and anthropogenic disturbances, and the effects of these compound perturbations are not well known. In this investigation, we examine whether tolerance to one stressor, metals, results in a cost of increased sensitivity to an additional stressor, ultraviolet-B (UV-B) radiation. Heavy metal pollution is recognized as a major environmental problem in Rocky Mountain streams. These high-elevation, typically clear streams may be at particular risk to elevated UV-B levels associated with reduced levels of ozone. Microcosm experiments were conducted using natural stream benthic communities collected from a reference site and a site with a long-term history of heavy-metal pollution. Direct and interactive effects of heavy metals and UV-B radiation on structural and functional characteristics of benthic communities were evaluated among four treatments: control, UV-B, metals, and metal and UV-B. Communities from the metal-polluted site were more tolerant of metals but less tolerant to UV-B compared to reference communities. Increased mayfly drift and reduced metabolism in response to metal exposure were observed in reference communities but not in the metal-polluted communities. In contrast to these results, UV-B radiation significantly reduced community metabolism, total macroinvertebrate abundance, and abundances of mayflies, caddisflies, and dipterans from the metal-polluted site, but had no effects on benthic communities from the reference site. ANOSIM results demonstrated that community responses differed among treatments at both sites. Metals had the largest impact on community differences at both sites, while UV-B had greater impacts at the metal-polluted site. This research demonstrates the need to account for potential costs associated with tolerance and that these costs can result in behavioral, structural, and functional impacts to benthic communities.     

对美国格林威治湾底栖动物造成危害的潜在胁迫因子的诊断

格林威治湾是纳拉甘西特湾一处受到多种影响因子作用的城市化形成港湾。本研究鉴定了对于格林威治湾底栖动物的重要影响因素。首先利用现存数据与信息来验证水体受损情况。其次确定了影响来源，影响因素和具体影响的存在。继而探究了来源，影响因素和具体影响之间的关系。这使我们能够鉴定出最可能危害水体的影响因素。本研究评估了化学制品、营养物质和悬浮沉积物3类污染物。这种证据权重的方法表明格林威治湾主要受到富营养化相关的影响因素危害。格林威治湾的沉积物富含碳，低溶解氧浓度的情况十分常见，尤其在格林威治湾西部。底栖生物群落出现发育不良的情况，与在氧气不足情况下的预测结果吻合。尽管我们的分析表明环境中的污染物浓度可能导致有害结果的出现，我们并未在结果中检出毒性。这是由于沉积物中存在大量的有机物，这些有机物限制了污染物的生物可利用性。我们的分析还表明悬浮沉积物的影响对于湾区的大部分区域而言几乎不存在。本分析展示了诊断法步骤可以用于组织和评估影响格林威治湾生态健康的潜在影响因素。诊断法步骤对于管理受到多重因素影响的水体非常有用。
精选自Marguerite Pelletier, Kay Ho, Mark Cantwell, Monique Perron, Kenneth Rocha, Robert M. Burgess, Roxanne Johnson, Kenneth Perez, John Cardin, Michael A. Charpentier. Diagnosis of potential stressors adversely affecting benthic invertebrate communities in Greenwich Bay, Rhode Island, USA. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 449–462, July 2017. DOI: 10.1002/etc.3562
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3562/full
     

Community response patterns: evaluating benthic invertebrate composition in metal-polluted streams.

Human activities are modifying the condition and character of ecosystems at a rapid rate. Because of these rapid changes, questions concerning how ecosystems and their assemblages respond to anthropogenic stressors have been of general interest. Accurate prediction of assemblage composition in ecosystems with anthropogenic degradation requires that we assess both how assemblages respond to stressors and the generality of the responses. We ask whether assemblage composition among stream sites becomes more similar after exposure to a common stressor. Using data from biological monitoring programs in the southern Rocky Mountain ecoregion of Colorado and in West Virginia, we compare benthic invertebrate similarity and assemblage composition among sites having different levels (background, low, medium, and high) of heavy-metal pollution. Invertebrate assemblages were most similar within the background metal category, and similarity was progressively lower in low, medium, and high metal categories. An analysis of the frequency of occurrence of genera within metal categories reveals taxonomic shifts that conform to expectations based on metal tolerance of benthic invertebrates. However, different metal-tolerant genera were found at different metal-impacted sites, suggesting that local abiotic and biotic processes may influence the identity of the metal-tolerant genera that become established in polluted sites. Low community similarity in the medium and high-metal categories suggests that accurate prediction of assemblage composition at impacted sites may be challenging.     

Benthic community respiration in the N.W. Atlantic Ocean: in situ measurements from 40 to 5200 m

Benthic community respiration was measured in situ at 9 stations along the Gay Head-Bermuda transect from depths of 40 to 5200 m. Three methods were used; bell jar respirometers, grab respirometers, and free vehicle respirometers. Benthic community respiration rates spanned three orders of magnitude, decreasing from 21.5 ml O₂ m^-2 h^-1 at 40 m in November to 0.02 ml O₂ m^-2 h^-1 at 5200 m. Rates decreased two orders of magnitude between 40 and 1800 m and then significantly declined again between the continental rise (3650 m) and the abyssal plain stations. Predictive equations for benthic community respiration along the transect reflect a strong correlation with depth of water. Of lesser significance are the correlations with water temperature, dissolved oxygen, benthic animal biomass, surface primary productivity and sediment organic matter. Calculations show that annual benthic respiration can utilize 1 to 2% of the surface primary productivity. Of the 2 to 7% organic carbon fixed at the surface which supposedly reaches the bottom, only 15 to 29% is utilized by the benthic community at 2200, 3000, and 3650 m. The energy requirements of other biological components of deep-sea benthic communities, such as benthopelagic and macro-epibenthic animals, not included in these measurements, must also be considered in calculating a balance of carbon.Contribution from Scripps Institution of Oceanography.     

德兴铜矿废水对乐安江底栖动物群落的影响

对乐安江水系的底栖动物及其生活环境进行的研究表明，位于乐安江上游的德兴铜矿排出的大量酸性废水对主活在该水系中的底栖动物的分布及其群落结构会产生直接影响．废水中的各种污染物质，尤以重金属（特别是铜和铅、锌、镉）对底栖动物群落的抑制作用最大．在下游，随着同污染源距离的增加，河流的污染状况逐渐减轻，底栖动物种类多样性逐渐增加，清洁种类逐渐恢复．另外，河流水量的季节性变化对河流自身的净化作用会产生很大影响．     

Seasonal and annual variability in an epifaunal community in the German Bight

While the benthic infauna of the North Sea has been studied intensively over the past decades, few studies have focused on the larger mobile epifauna. Studies carried out to date have described the distribution of epifaunal communities over the whole of the North Sea, but variability within the identified communities, which occurs on a much smaller scale, has so far remained unstudied. This is the first study to describe seasonal and annual variability of an epifaunal assemblage in the German Bight area, where environmental conditions are highly variable. The benthic community was sampled with a 2 m beam trawl from 1998 to 2001. The echinoderms Ophiura albida and Asterias rubens and the crustacean Pagurus bernhardus were the dominant species caught throughout the study period. Overall the species composition of the catches was relatively consistent, while abundances of dominant species fluctuated considerably between sampling periods. Differences between sampling periods were not only influenced by the abundances of dominant species, but also by less dominant species such as Ophiura ophiura, Astropecten irregularis, Corystes cassivelaunus, Crangon crangon and Aphorrahis pespelicani. The abundances of these species varied annually and seasonally in the assemblage. Clear differences between summer and winter in the species composition, abundance and biomass were identified. Annual and seasonal changes were most likely linked to migratory movements of epifauna into and out of the area under investigation. Temporal changes in species composition and abundance correlated best with water temperatures, while the spatial distribution of the total biomass over the whole sampling period was correlated with sediment characteristics. Anthropogenic influences such as fishing activity and chronic large-scale eutrophication are thought to have influenced the community on a long-term basis, but have been considered unlikely causes for the short-term variability described by this study.Communicated by J.P. Thorpe, Port Erin     

Use of Ordination Techniques to Follow Community Succession from Oil Impact to Recovery in the Field

Much effort has been directed toward elucidating pollution effects on marine benthic communities (Pearson and Rosenberg, 1978; Sanders et al., 1980; NAS 1985). Less effort has been directed at methods of data analysis which will identify distribution patterns and relationships between communities. Traditional community structure summary parameters such as species richness and various indices of diversity utilize only part of the information contained in a data set and are not very useful in elucidating relationships between communities of animals.     

A new apparatus for force measurement in marine bioadhesion

In an experimental study on the effect of parrotfish (probably Scarus taeniurus) grazing on the structure of benthic reef communities, fishes in densities of 0.6 to 1.5 parrotfish per m² or 9 to 17 g wet weight of fish per m² of feeding surface were found to have an optimum effect, resulting in the greatest benthic species richness and biomass on 2-dimensional surfaces. The presence of refuges (3-dimensional habitats), however, has a greater impact on bemthic community structure (number of species and biomass) than does just the density of parrotfish in such an experimental system. Coral recruitment is enhanced by the presence of refuges and, like coralline algae, is more successful under increased grazing pressure. These optimum densities of parrotfishes relate well to observed field densities where, in a collection from a Hawaiian patch reef, there were 1.1 fish or 10.8 g wet weight of parrotfish per square meter of collection area. The success of coralline algae and corals under high grazing pressure may have important consequences for the stability and structure of modern coral reefs.     

Influence of a dominant consumer species reverses at increased diversity

Theory and experiments indicate that changes in consumer diversity affect benthic community structure and ecosystem functioning. Although the effects of consumer diversity have been tested in the laboratory and the field, little is known about effects of consumer diversity in the subtidal zone, one of the largest marine habitats. We investigated the grazing effects of sea urchins on algal abundance and benthic community structure in a natural subtidal habitat of the Galápagos Islands. Three species of urchins (Eucidaris, Lytechinus, and Tripneustes) were manipulated in inclusion cages following a replacement design with three levels of species richness (one, two, and three species) with all possible two-species urchin combinations. Identity was the main factor accounting for changes in the percentage of substrate grazed and benthic community structure. Two out of the three two-species assemblages grazed more than expected, suggesting a richness effect, but analyses revealed that this increased grazing was due to a sampling effect of the largest and commercially valued urchin species, Tripneustes. Benthic community structure in treatments with Eucidaris, Lytechinus, and Tripneustes alone was significantly different at the end of the experiment, suggesting that resource use differentiation occurred. Communities in Tripneustes enclosures were characterized by abundant crustose coralline algae and grazed substrate, while those without it contained abundant green foliose algae (Ulva sp.). An unexpected emergent property of the system was that the most species-rich urchin assemblage underyielded, grazing less than any other assemblage with Tripneustes, effectively reversing its dominant influence observed in the two-species treatments. While further experiments are needed to discern the mechanisms of underyielding, it may be related to changing interspecific interactions as richness increases from two to three species or to density-dependent Tripneustes grazing. This study highlights the general importance of evaluating consumer richness effects across the entire range of species richness considered, as the performance of the most species-rich consumer assemblage could not be predicted by manipulations of intermediate levels of consumer species richness.     

Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary,Taiwan

The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.

The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.

Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments.     

Add-on conservation benefits of marine territorial user rights fishery policies in central Chile.

To combine the rational use of marine benthic resources and economic development of small-scale fishers, Chile passed legislation in 1991 establishing a comanagement policy that grants exclusive territorial user rights for fisheries (TURFs) to artisanal fisher organizations in well-defined inshore coastal areas, known as Management and Exploitation Areas for Benthic Resources (MEABRs). In general the policy has been proclaimed a management and economic success because benthic resource abundances have increased inside MEABRs in comparison with open-access areas. However, there is a lack of studies assessing the impact of this management policy on nontargeted subtidal species and community assemblages and the policy's implications for biodiversity and conservation. This study starts to fill this gap and links the allocation of TURFs for benthic resources with add-on conservation benefits for species that are not directly linked with the fishery policy. Comparative subtidal surveys inside vs. outside MEABRs were used to assess the effects of three MEABRs on managed targeted benthic species, biodiversity (species richness), and community assemblages in central Chile. Surveys focused exclusively on subtidal kelp forest habitats dominated by Lessonia trabeculata, spanning 4-12 m in depth and with similar levels of habitat complexity. The study comprised: (1) quantification of kelp forest complexity, (2) understory survey of sessile species, (3) quantification of conspicuous benthic macroinvertebrates, including those under management, and (4) quantification of reef-fish species inside the kelp habitat. Results showed population enhancement of target-managed invertebrates inside MEABRs. Moreover, reef-fish species were significantly more diverse and abundant inside MEABRs, and community assemblages of nontarget benthic invertebrates and reef fish were significantly different inside vs. outside MEABRs. The comanagement of inshore benthic resources in Chile, through MEABRs aims for the sustainability of invertebrate and algae stocks. However, our study shows that this management tool, which in practice restricts access to the entire management area, provides important conservation add-on effects for species that are not the focus of the management policies. Therefore, in Chile, the hundreds of already established MEABRs could represent an important ancillary network, which complements the biodiversity objectives of fully protected areas such as no-take marine protected areas or others.     

Inconsistent temporal changes in the megabenthos of the English Channel

A survey was undertaken of the benthic communities found at ten stations that were sampled by Norman Holme in the 1950s. These stations were selected because Holme recorded the presence of large bivalve species (Glycymeris glycymeris and Paphia rhomboides). Fauna with large body-size are known to be most susceptible to disturbance by human activity, so the presence or absence of these organisms might indicate whether such disturbance has increased at these sites since the 1950s. As expected, differences were detected in the community composition between sites that were located in deeper or shallower water. These differences were consistent for the communities sampled in the present study and for those sampled by Holme. The brittlestar Ophiothrix fragilis was highly abundant at only one site. Nevertheless, long-lived bivalve species still occurred at most of the sites sampled in 1998. G. glycymeris was absent from two sites sampled in 1998 and P. rhomboides was absent from only one site in 1998. Holme suggested that his reported decline in the abundance of O. fragilis might be attributed to the increase in bottom fishing in the English Channel. However, the continued presence of long-lived bivalves at most sites would suggest that other factors could be responsible. A comparison of bivalve and echinoderm species that occurred in the 1950s and in 1998 indicated the occurrence of relatively large temporal changes, as might be expected over a period of more than 40 years. However, this occurred at eight of the ten sites. At two sites, the spatial variation was quantitatively similar to the temporal variation. This suggests that areas of the sea bed exist that have a similar community composition to those found prior to the general increase in bottom-fishing disturbance.     

Sedimentary Pigments and Organic Matter in Relation to Benthic Fauna in the Tan-Shui Estuary, Taiwan

The benthic ecological structure of the Tan-Shui estuary, Taiwan is changed due to long term effects of dumping of urban wastewater and of engineering actions. to monitor these changes, we sampled and analyzed benthos and sediment from 12 stations on the estuary.

The composition of the dominant species of benthos varied seasonally, with molluscan and crustacean species having greater numbers and higher frequencies of occurrence than other species. the dominant taxa during winter were Nassarius sp. and Maldanidae at two stations. Analysis using Simpson's index and Shannon's index showed the benthic community varied more in coastal areas than in offshore areas.

Physicochemical analysis showed that most of the Tan-Shui estuary consisted of sandy sediment. the variations in concentrations of organic carbon and total nitrogen at each station were small. Although the concentrations of chlorophyll-a and carotenoid at all stations were generally low, the two stations had the highest concentrations, and we concluded that the concentration of pigments in these sediments was related to the abundance of benthos. the community structure of the benthos reflected the characteristics of the sediments, and benthic species exhibited selection of and adaptation to specific sedimentary environments.