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1.
Laikre L  Palme A  Josefsson M  Utter F  Ryman N 《Ambio》2006,35(5):255-261
Introduction of alien species is a major threat to biological diversity. Although public attention typically focuses on the species level, guidelines from the Convention of Biological Diversity define alien species to include entities below species level. This inclusion recognizes that release of nonlocal populations of native species may also result in negative effects on biodiversity. In practice, little is known about the extent, degree of establishment, or the effects on natural gene pools of such releases. Existing information on the releases in Sweden shows that alien populations are spread to a great extent. The most commonly released species include brown trout, Atlantic salmon, Arctic char, common whitefish, Scots pine, Norway spruce, mallard duck, gray partridge, and pheasant. Although millions of forest trees, fish, and birds are released annually, poor documentation makes the geographic and genetic origin of these populations, as well as the sites where they have been released, largely unclear. We provide recommendations for urgently needed first steps relating to the risks and problems associated with release of alien populations.  相似文献   

2.
Effects of environmental chemical pollution can be observed at all levels of biological organization. At the population level, genetic structure and diversity may be affected by exposure to metal contamination. This study was conducted in Huautla, Morelos, Mexico in a mining district where the main contaminants are lead and arsenic. Peromyscus melanophrys is a small mammal species that inhabits Huautla mine tailings and has been considered as a sentinel species. Metal bioaccumulation levels were examined by inductively coupled plasma mass spectrometry and genetic analyses were performed using eight microsatellite loci in 100 P. melanophrys individuals from 3 mine tailings and 2 control sites. The effect of metal bioaccumulation levels on genetic parameters (population and individual genetic diversity, genetic structure) was analyzed. We found a tissue concentration gradient for each metal and for the bioaccumulation index. The highest values of genetic differentiation (Fst and Rst) and the lowest number of migrants per generation (Nm) were registered among the exposed populations. Genetic distance analyses showed that the most polluted population was the most genetically distant among the five populations examined. Moreover, a negative and significant relationship was detected between genetic diversity (expected heterozygosity and internal relatedness) and each metal concentration and for the bioaccumulation index in P. melanophrys. This study highlights that metal stress is a major factor affecting the distribution and genetic diversity levels of P. melanophrys populations living inside mine tailings. We suggest the use of genetic population changes at micro-geographical scales as a population level biomarker.  相似文献   

3.
Liu P  Yang YS  Hao CY  Guo WD 《Chemosphere》2007,68(8):1497-1505
Environmental and ecological risk assessment always provide useful evidence for characterisation and conservation of the rare and endangered species, e.g. seven-son flower (Heptacodium miconioides Rehd.). Seven-son flower is a deciduous arbor species, but endangered, with a restricted distribution in the subtropical forests of China. Genetic risk assessment of 56 samples of the flower from nine main populations in Zhejiang (China) was carried out by using the RAPD analysis. This was to study the ecological characteristics, spatial distribution and genetic features of the seven-son flower communities and establish a feasible conservation plan. Twenty-one primers screened from 50 yielded 119 RAPD bands with 72 polymorphic products and 60.50% of total bands. The genetic variation was found to be partitioned mainly among rather than within populations. Percentages of genetic diversity among populations were quantified by Shannon index and the Nei's gene diversity coefficient. AMOVA also demonstrated that these relict populations were highly differentiated. The high level of population variation observed is in contrast to that expected for a primarily outcrossed woody perennial plant, and suggests that there may be a degree of inbreeding. The dendrogram constructed from genetic distances through UPGMA method based on Nei's coefficients shows two groups among nine population clusters, which is further supported by a principle components analysis (PCA) of RAPD phenotypic data. The analysis showed that the biologic characteristics and habitat fragmentation were the reasons of the great genetic variation among populations. Some strategies of its genetic diversity conservation were proposed in the fragmented habitats based on its genetic structure and its biological characteristics in this study.  相似文献   

4.
Changes in DNA sequences affecting cryptic intraspecific variability are very important mechanisms of plant microevolutionary processes, initiating species diversification. In polluted environments, intra- and interpopulation changes at the molecular level proceed rapidly and lead to the formation of new ecotypes in a relatively short time. We used ISSR PCR fingerprinting data to analyze the genetic diversity and genetic structure of seven populations of Viola tricolor: four growing on soil contaminated with heavy metals (Zn, Pb, Cd; waste heaps) and three from control soil. The populations from the polluted sites showed higher genetic polymorphism (%(poly)=84%) and gene diversity (H(T)=0.1709) than the control populations (%(poly)=75% and H(T)=0.1448). The number of private markers we detected within metallicolous (MET) populations was more than double that found within non-metallicolous (NON) populations (15 vs. 7). The STRUCTURE and UPGMA analyses showed clear genetic differences between the NON and MET populations. Based on broad analyses of the genetic parameters, we conclude that the effect of these polluted environments on the genetic diversity of the MET populations, separating them from the NON populations, is evidence of microevolutionary processes at species level, leading to species divergence and the emergence of local ecotypes better adapted to their different environments.  相似文献   

5.
BACKGROUND, AIM AND SCOPE: Discussions on management of whales and whaling are factually monopolized by the International Whaling Commission (IWC), resulting in a limitation of information flow to outside communities. With an aim to improve the situation, this article briefly reviews whaling and dolphin/porpoise fisheries in Japan, which is recognized to be the world largest cetacean exploitation. MAIN FEATURES: The Japanese government grants an annual take of 22,647 cetaceans of 15 species for scientific whaling and various kinds of active dolphin/porpoise fisheries by the nationals. Further, over 100 baleen whales and numerous small cetaceans are taken in passive net fisheries. They are used mostly for human consumption and some for aquarium display. RESULTS: Sustainability of the take is not evident and some populations have shown a historical decline. The Japanese program of scientific whaling has been reviewed by IWC and its Scientific Committee (SC), although they have arrived at no consensus. DISCUSSION: The current scientific whaling program invites arguments from the view points of science as well as concerning the ethics of scientists, economy, and interpretation of the International Convention for Regulation of Whaling (ICRW) of 1946. The scientific whaling and other Japanese cetacean fisheries are benefited from nationalistic public attitude, and ambiguity and weakness of the ICRW. CONCLUSIONS: Japanese cetacean harvest will continue supported by domestic demand for whale products as long as the proceeds can sustain the operation, even with criticisms from outside communities. RECOMMENDATIONS AND PERSPECTIVES: For safe management of small cetaceans exploited by Japan, studies are urgent on the population structure, abundance and validity of catch statistics. The results should be open to scientific communities.  相似文献   

6.
Visible injury caused by ozone is recorded every year in native plant species growing in Great Smoky Mountains National Park (USA). One of the most sensitive species, cutleaf coneflower (Rudbeckia laciniata L.), shows great variation in symptoms between and within populations but the causes of this variation and its ecological significance are currently unknown. This paper presents data relating to genetic variation, ozone concentrations, stomatal conductance and light (PAR) within populations. The data show that populations differ in genetic diversity, one consisting of only three genets while another was very diverse. In the former population, symptoms varied greatly within a single genet, pointing to a large micro-environmental influence. Measurements of ozone, stomatal conductance and PAR within plant canopies suggest that variation in symptom expression is unlikely to be due to differences in ozone flux and more likely to be due to variation in light. The variation in visible symptoms raises the question of what bioindicators actually indicate, and it suggests that symptoms should be interpreted with great caution until the underlying causes of that variation are fully understood.  相似文献   

7.
Alamanov A  Mikkola H 《Ambio》2011,40(5):479-495
This paper aims to identify challenges, and threats, and further explore opportunities for a new Biodiversity Friendly Fisheries Management Regime on the Issyk-Kul Lake in the Kyrgyz Republic. This lake is the second largest high-altitude lake in the world providing recreational and small-scale fishing activities as well as cage culture of introduced species. The populations of several indigenous species are seriously threatened, because many of the introduced species are potential predators. We examine the root causes for overfishing and relationships of alien and endemic fish species in Issyk-Kul Lake and give possible policy options that can help remediate or mitigate the biodiversity degradation. This analysis focuses on necessary legal modifications, institutional cooperation, the protection of selected endemic fish species, control of the alien species, the sustainable extension services and management of fish ponds. Fisheries co-management is one option to explore shared stewardship and empowering user groups on the lake. A comprehensive fisheries management plan is also needed, in addition to immediate action and further studies on the following wider aspects: water management/irrigation issues, water-quality assessment near cage cultures, socio-cultural issues, resource inventory, and assessing fish biology and the lake ecosystem.  相似文献   

8.
General effects of climate change on Arctic fishes and fish populations   总被引:3,自引:0,他引:3  
Projected shifts in climate forcing variables such as temperature and precipitation are of great relevance to arctic freshwater ecosystems and biota. These will result in many direct and indirect effects upon the ecosystems and fish present therein. Shifts projected for fish populations will range from positive to negative in overall effect, differ among species and also among populations within species depending upon their biology and tolerances, and will be integrated by the fish within their local aquascapes. This results in a wide range of future possibilities for arctic freshwater and diadromous fishes. Owing to a dearth of basic knowledge regarding fish biology and habitat interactions in the north, complicated by scaling issues and uncertainty in future climate projections, only qualitative scenarios can be developed in most cases. This limits preparedness to meet challenges of climate change in the Arctic with respect to fish and fisheries.  相似文献   

9.
Johannesson K  Smolarz K  Grahn M  André C 《Ambio》2011,40(2):179-190
Environmental change challenges local and global survival of populations and species. In a species-poor environment like the Baltic Sea this is particularly critical as major ecosystem functions may be upheld by single species. A complex interplay between demographic and genetic characteristics of species and populations determines risks of local extinction, chances of re-establishment of lost populations, and tolerance to environmental changes by evolution of new adaptations. Recent studies show that Baltic populations of dominant marine species are locally adapted, have lost genetic variation and are relatively isolated. In addition, some have evolved unusually high degrees of clonality and others are representatives of endemic (unique) evolutionary lineages. We here suggest that a consequence of local adaptation, isolation and genetic endemism is an increased risk of failure in restoring extinct Baltic populations. Additionally, restricted availability of genetic variation owing to lost variation and isolation may negatively impact the potential for evolutionary rescue following environmental change.  相似文献   

10.
Jiddawi NS  Ohman MC 《Ambio》2002,31(7-8):518-527
Fishery resources are a vital source of food and make valuable economic contributions to the local communities involved in fishery activities along the 850 km stretch of the Tanzania coastline and numerous islands. Small-scale artisanal fishery accounts for the majority of fish catch produced by more than 43 000 fishermen in the country, mainly operating in shallow waters within the continental shelf, using traditional fishing vessels including small boats, dhows, canoes, outrigger canoes and dinghys. Various fishing techniques are applied using uncomplicated passive fishing gears such as basket traps, fence traps, nets as well as different hook and line techniques. Species composition and size of the fish varies with gear type and location. More than 500 species of fish are utilized for food with reef fishes being the most important category including emperors, snappers, sweetlips, parrotfish, surgeonfish, rabbitfish, groupers and goatfish. Most of the fish products are used for subsistence purposes. However, some are exported. Destructive fishing methods such as drag nets and dynamite fishing pose a serious problem as they destroy important habitats for fish and other organisms, and there is a long-term trend of overharvested fishery resources. However, fishing pressure varies within the country as fishery resources are utilized in a sustainable manner in some areas. For this report more than 340 references about Tanzanian fishery and fish ecology were covered. There are many gaps in terms of information needed for successful fishery management regarding both basic and applied research. Most research results have been presented as grey literature (57%) with limited distribution; only one-fifth were scientific publications in international journals.  相似文献   

11.
Genotype frequencies of glucose-6-phosphate isomerase (GPI) allozymes differed significantly among populations of the spotfin shiner Notropis spilopterus from sites with varying water quality. Frequencies of shiners with a GPI-2 BB genotype decreased significantly at sites with reduced water quality. Alternatively, the total frequencies of shiners with a genotype of GPI-2 AA and AB increased at sites with reduced water quality. Individuals with certain allozyme genotypes may be more sensitive to the toxic effects of polluted waters than those with other genotypes. The selection of individuals with sensitive genotypes may reduce genetic diversity in populations and thus increase the susceptibility of these populations to additional novel stresses. Because allele and genotype frequencies of GPI-2 were correlated with water quality, electrophoretic determination of genetic structure in fishes may be a useful tool for monitoring the health of aquatic populations.  相似文献   

12.
Arctic freshwater and diadromous fish species will respond to the various effects of climate change in many ways. For wide-ranging species, many of which are key components of northern aquatic ecosystems and fisheries, there is a large range of possible responses due to inter- and intra-specific variation, differences in the effects of climate drivers within ACIA regions, and differences in drivers among regions. All this diversity, coupled with limited understanding of fish responses to climate parameters generally, permits enumeration only of a range of possible responses which are developed here for selected important fishes. Accordingly, in-depth examination is required of possible effects within species within ACIA regions, as well as comparative studies across regions. Two particularly important species (Arctic char and Atlantic salmon) are examined as case studies to provide background for such studies.  相似文献   

13.
Participatory research has not been a conspicuous methodology in developing nations for studying invasive pests, an increasing threat to the sustainable development in the tropics. Our study presents a community-based monitoring system that focuses on three invasive potato tuber moth species (PTM). The monitoring was developed and implemented by young farmers in a remote mountainous area of Ecuador. Local participants collected data from the PTM invasion front, which revealed clear connection between the abundance of one of the species (Tecia solanivora) and the remoteness to the main market place. This suggests that mechanisms structuring invasive populations at the invasion front are different from those occurring in areas invaded for longer period. Participatory monitoring with local people may serve as a cost-effective early warning system to detect and control incipient invasive pest species in countries where the daily management of biological resources is largely in the hands of poor rural people.  相似文献   

14.
Medina MH  Correa JA  Barata C 《Chemosphere》2007,67(11):2105-2114
Polluting events can change community structure and ecosystem functioning. Selection of genetically inherited tolerance on exposed populations, here referred as micro-evolution due to pollution, has been recognized as one of the causes of these changes. However, there is a gap between studies addressing this process and those assessing effects at higher levels of biological organization. In this review we attempt to address these evolutionary considerations into the ecological risk assessment (ERA) of polluting events and to trigger the discussion about the consequences of this process for the ecosystem response to toxic stress. We provide clear evidence that pollution drives micro-evolutionary processes in several species. When this process occurs, populations inhabiting environments that become polluted may persist. However, due to the existence of ecological costs derived from the loss of genetic variability, negative pleiotropy with fitness traits and/or from physiological alterations, micro-evolution due to pollution may alter different properties of the affected populations. Despite the existence of empirical evidence showing that safety margins currently applied in the ERA process may account for pollution-induced genetic changes in tolerance, information regarding long-term ecological consequences at higher levels of biological organization due to ecological costs is not explicitly considered in these procedures. In relation to this, we present four testable hypotheses considering that micro-evolution due to pollution acts upon the variability of functional response traits of the exposed populations and generates changes on their functional effect traits, therefore, modifying the way species exploit their ecological niches and participate in the overall ecosystem functioning.  相似文献   

15.
- Sustainable chemistry - Section editors: Klaus Günter Steinhäuser, Steffi Richter, Petra Greiner, Jutta Penning, Michael AngrickBackground, Aim and Scope Recent developments in European chemicals policy, including the Registration, Evaluation and Authorization of Chemicals (REACH) proposal, provide a unique opportunity to examine the U.S. experience in promoting sustainable chemistry as well as the strengths and weaknesses of existing policies. Indeed, the problems of industrial chemicals and limitations in current regulatory approaches to address chemical risks are strikingly similar on both sides of the Atlantic. We provide an overview of the U.S. regulatory system for chemicals management and its relationship to efforts promoting sustainable chemistry. We examine federal and state and examine lessons learned from this system that can be applied to developing more integrated, sustainable approaches to chemicals management.Main Features There is truly no one U.S. chemicals policy, but rather a series of different un-integrated policies at the federal, regional, state and local levels. While centerpiece U.S. Chemicals Policy, the Toxic Substances Control Act of 1976, has resulted in the development of a comprehensive, efficient rapid screening process for new chemicals, agency action to manage existing chemicals has been very limited. The agency, however, has engaged in a number of successful, though highly underfunded, voluntary data collection, pollution prevention, and sustainable design programs that have been important motivators for sustainable chemistry. Policy innovation in the establishment of numerous state level initiatives on persistent and bioaccumulative toxics, chemical restrictions and toxics use reduction have resulted in pressure on the federal government to augment its efforts.Results and Conclusions It is clear that data collection on chemical risks and phase-outs of the most egregious chemicals alone will not achieve the goals of sustainable chemistry. These alone will also not internalize the cultural and institutional changes needed to ensure that design and implementation of safer chemicals, processes, and products are the focus of the future. Thus, a more holistic approach of ‘carrots and sticks’ – that involves not just chemical producers but those who use and purchase chemicals is necessary. Some important lessons of the US experience in chemicals management include: (1) the need for good information on chemicals flows, toxic risks, and safer substances.; (2) the need for comprehensive planning processes for chemical substitution and reduction to avoid risk trade-offs and ensure product quality; (3) the need for technical and research support to firms for innovation in safer chemistry; and (4) the need for rapid screening processes and tools for comparison of alternative chemicals, materials, and products.  相似文献   

16.
The population genetic composition of Poa annua L. was studied by starch electrophoresis along a transect running NE from an organic reagents factory at Shanghai, China. Five enzyme systems were stained. We have reached the following preliminary conclusions: (1). Organic pollution has dramatically changed genotypic frequencies at some loci of Poa annua populations. At polluted sites, significant deviations from Hardy-Weinberg equilibrium were observed on loci Sod-1 and Me due to the excess of heterozygote. Especially in the two nearest sites to pollution source, all the individuals were heterozygous at locus Sod-1. The data suggests that heterozygotes were more tolerant to organic pollution than homozygotes, indicating the fitness superiority of heterozygotes. (2). A tendency towards clinal changes of allele frequencies was found at some polymorphic loci. Frequencies of the common alleles at loci Sod-1, Me and Fe-1 increased as the distance to the pollution source increased. (3). The effective number of alleles per locus, and the observed and expected heterozygosity were much higher in the pollution series than in the clear control site (Botanic Park population), but genetic multiplicity (number of alleles per locus) was lower than for the control. (4). Most genetic variability was found within populations, and only 2.56% were among populations of the polluted series. However, 9.48% of the total genetic variation occurred among populations when including the Botanic Park population. The genetic identity between populations of the pollution series (0.9869-1.0000, mean 0.9941) was higher than those between the pollution series and the Botanic Park population. UPGMA divided the five populations into two groups. One contained the four polluted populations, and the other only contained the Botanic Park population.  相似文献   

17.
As goose populations increase in abundance, their influence on ecological processes is increasing. We review the evidence for key ecological functions of wild goose populations in Eurasia and North America, including aquatic invertebrate and plant propagule transport, nutrient deposition in terrestrial and aquatic ecosystems, the influence of goose populations on vegetation biomass, carbon storage and methane emission, species diversity and disease transmission. To estimate the implications of their growing abundance for humans, we explore how these functions contribute to the provision of ecosystem services and disservices. We assess the weight, extent and trends among such impacts, as well as the balance of their value to society. We examine key unresolved issues to enable a more balanced assessment of the economic costs or benefits of migratory geese along their flyways, including the spatial and temporal variation in services and their contrasting value to different user groups. Many ecological functions of geese are concluded to provide neither services nor disservices and, ecosystem disservices currently appear to outweigh services, although this varies between regions. We consider an improved quantification of ecosystem services and disservices, and how these vary along population flyways with respect to variation in valuing certain cultural services, and under different management scenarios aimed at reducing their disservices, essential for a more balanced management of goose populations.  相似文献   

18.
Saulamo K  Thoresson G 《Ambio》2005,34(2):120-124
Pikeperch Sander lucioperca (L.) were tagged in an area where ten small independent management units regulate fisheries, in order to analyze the relevance of migrations for the management. A total of 465 fishes were tagged in connection with the spawning migration. The number of recaptures was 96. The distribution of recaptures between areas and that of total catches, estimated from questionnaire to housholds and, individuals in the survey area, were correlated. The comparison of tagging and recapture dates showed that the same pikeperch migrated to the spawning areas at the same time in two subsequent years, indicating the existence of individual spawning behavior. A modified yield/recruit-model demonstrated that in situations where the dispersal area of a pikeperch stock overlaps with several management areas, the risk of overfishing is very high. Management of this kind of fisheries needs cooperation between units as well as sound data on the movements of pikeperch to define the effects of fishing regulations.  相似文献   

19.
Moen J  Danell O 《Ambio》2003,32(6):397-402
During the last decade, several well-publicized grazing-related incidents of vegetation degradation have helped to form an official opinion of overutilization of some mountain areas and a concern that Swedish reindeer husbandry may not be ecologically sustainable. We examine these examples in a temporal and management perspective to assess the scale of impact on summer grazing grounds in the Swedish mountains. Long-term data on population dynamics of reindeer show no trend with fluctuations around 225 000 animals for the last century. Data on grazing effects from L?ngfj?llet (Dalarna) and Mitt?kl?ppen (H?rjedalen) are discussed in detail. We compare these data to the situation in Finnmark, Norway, and in northern Finland where reindeer husbandry in recent decades does not seem to have been ecologically sustainable. We conclude that large-scale overexploitation by reindeer in the Swedish mountains is not evident. However, strong grazing and trampling effects may be found around enclosures and fences.  相似文献   

20.
We here review the collision risks posed by large-bodied, flocking geese to aircraft, exacerbated by recent major increases in northern hemisphere goose populations and air traffic volume. Mitigation of goose–aircraft strike risks requires knowledge of local goose movements, global goose population dynamics and ecology. Airports can minimise goose strikes by managing habitats within the airport property, applying deterrents to scare geese away and lethal control, but goose migration and movements at greater spatial scales present greater challenges. Habitat management outside of airports can locally reduce goose attractiveness of peripheral areas, but requires stakeholder involvement and coordination. Information on bird strike rates, individual goose movements and goose population dynamics is essential to understand how best to reduce the risk of goose strikes. Avian radar provides tactical information for mitigation measures and strategic data on local patterns of goose migration and habitat use. In the face of expanding air traffic, goose distributions and populations, these threats need to be integrated with other local, national and international stakeholder involvement to secure viable solutions to multiple conflicts.  相似文献   

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