Ecological Impact

The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However, the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants was evaluated. Reference toxicants were rated in relation to the following criteria: (a) reproducibility, (b) low human health hazard, (c) feasibility of measurement, and (d) chemical stability. Potassium chloride (KCl) and ammonium chloride (NH,CI) were evaluated as possible alternatives to the one currently in common use, 2-chloroacetamide. Potassium chloride rated the best for the combination of the four criteria, followed by NH4C1 and 2-chloroacetamide. Coefficients of variation (C.V.s) from control charts of six definitive tests were used to measure reproducibility. The best reproducibility (lowest C.V.) was shown by KC1, followed by NH4C1 and 2-chloroacetamide. Toxicants ranked KCl < NH4C1 << 2-chloroacetamide in terms of health hazard; and KC1 = NH,Cl> 2-chloroacetamide in terms of measurement feasibility. Both 2-chloroacetamide and NH,Cl changed in concentration during testing. Evidence is also presented that 2-chloroacetamide degrades rapidly during testing, and that, as dead worms decay, ammonification may be adding another toxicant, ammonia, to tests.

A quick search of "exurbia" on the internet yields various definitions: 'the region outside the suburbs of a city, consisting of residential areas (exurbs) that are occupied predominantly by rich commuters (exurbanites) (www. wordreference.com/English); and the cryptically self-referential 'a typically exurban area ' (www.bartleby.com). Nighttime satellite imagery provided by the Defense Meteorological Satellite Program's Operational Linescan System (DMSP OLS) shows expansive areas of low light surrounding all major metropolitan areas. These areas would be characterized as pure vegetation by 30 meter resolution Landsat imagery yet they contain large numbers of people who have significant social, economic, and ecological impacts (e.g. traffic congestion and problems associated with the urban-wildlands interface). Questions explored in this paper are: 1) How big are 'exurban' areas in the United States?; 2) What cities have relatively large exurban areas and what cities have relatively small exurban areas?; How many people live in exurban areas?; 4) What are the costs and benefits of exurban areas and who pays for and/or receives them?; and finally, 5)Who lives in exurban areas? Conventional wisdom suggests that these 'exurbanites' are rich commuters who choose to live in natural settings beyond the city and suburbia; however, astronomic increases in real estate prices in places like Boston, New York, San Francisco, and Los Angeles suggest that many 'exurbanites' may be middle income teachers, police officers, and nurses trying to find affordable real estate. Our initial results suggest that 37% of the U.S. population lives in exurban areas that account for 14% of the land area. Purely urban areas account for 1.7% of the land area and house 55% of the population; and, rural areas (84% of the land area) contain only 8% of the population.

Treated sewage effluent is one of the most common types of pollution found in urban rivers. Both the quality and quantity of effluent result in various impacts on the receiving freshwater as well as marine environment. This paper outlines these impacts from an ecological, social and economic perspective, and provides some suggestions on the way forward with regards prioritising wastewater

The native distribution of the blue crab Callinectes sapidus in the western Atlantic extends from Nova Scotia to Argentina. Introduced to Europe at the beginning of the 20th century, it is currently recorded almost ubiquitously in the Mediterranean and in the Black Sea. An overview of the occurrence, abundance, and ecological impact of the species in southern European waters is provided; additionally, we present a pragmatic assessment of its management scenarios, explicitly considering the dual nature of C. sapidus as both an invasive species and a fishery resource. We emphasise that the ongoing expansion of C. sapidus in the region may represent a stimulating challenge for the identification and implementation of future strategies in the management of invasive crustaceans. The impact of the invader could be converted into an enhancement of the services delivered by southern European coastal ecosystems, while mitigation costs could be transformed into profits for local populations.

Tourism is an industry of the future, having the potential to provide significant revenues, and an industry of "beauty", because it will protect, preserve and contribute to arranging the environment affected by other human activities. This is why it is very important to know the evolution of this underdeveloped field in our country. This paper is intended as a study on current trends in Romanian tourism without any claim of being an exhaustive research on the industry, describing the main indices of tourist traffic and their influence on Romanian tourism. Nowadays, we witness three main trends in Romanian tourism: sustainability, ecotourism and the increasing presence of cultural tourism. Ecotourism, as a form of tourism, has emerged from people's need to withdraw in nature, to visit and learn about the natural areas which have or have not a national or international protection status. Cultural tourism appears as a type of tourism clearly differentiated from other forms or types of tourism, particularly through motivation. It can be defined as a form of tourist mobility whose primary goal is broadening the horizon of knowledge by uncovering its architectural and artistic heritage and the areas in which it originates. Sustainability for tourism, as for other industries, has three independent aspects: economic, socio-cultural and environmental. Sustainability implies permanence, which means that sustainable tourism requires the optimal use of resources, minimizing the negative economic, socio-cultural and ecological impact, maximizing the benefits upon local communities, national economies and conservation of nature. Regarding statistical data, in what quantity is concerned, there is an increase in Romanian tourism, but in what quality is concerned there is a setback for tourism in the last years. This aspect should make public authorities take concern in improving the infrastructure and the quality of the touristical activity and in diversifying entertainment.

Human intervention in the hydrologic basin of the Colorado River has eliminated water discharge and sediment supply to the river's mouth and its delta. After ∼95 years of applying strong flow control policies, the previous sedimentary budget in the delta has changed, the delta now being entirely exposed to the hydrodynamic forces in its basin. In order to assess the anthropogenic impact of water diversion on deltaic sedimentary processes and short-term delta geomorphic evolution, textural and mineralogical analyses were performed on 68 sediment samples collected from the river, estuary, beach, continental shelf, delta plain and desert. The results show a consistent NE to SW textural gradient on the shallow-marine platform adjacent to the Colorado River delta (an area known as the Upper Gulf of California), and a net cross-basinal sediment transport occurring in the same direction. Two opposing littoral transport components exist along the Sonoran and Baja Californian coasts: (1) net sediment transport from SE to NW along the Sonoran coast delivers sediments from the ocean into the estuarine basin through the Sonora channel of the deltaic system of the Colorado River; and (2) sediment transport from N to S along the Baja Californian coast removes sediments from the estuarine basin of the Colorado River into the Northern Gulf of California (NGC). The residual sediment transport pattern observed suggests a counterclockwise path of exchange of materials between the estuarine basin of the Colorado River and the NGC. Multivariate cluster and factor analyses of the heavy-mineral data reveal the existence of a sedimentary system dominated by two end-members, representing two heavy-mineral sedimentary provinces: (1) the Sonora province is characterized by a heavy-mineral suite of garnet and zircon (G–Z), whose sediment supply originates from the sandy sediments of the Sonora Mesa deposits and Sonora's Gran Desierto; and (2) the Baja California province is characterized by a hornblende–epidote–pyroxene (H–E–P) suite, whose sediments originate from the earlier supply of the Colorado River. Since the Colorado River is no longer supplying sediments from its drainage basin, the H–E–P-rich sediments now actively dispersed in the system have mainly originated through intense reworking of the delta. Moreover, G–Z-rich sediments are starting to invade areas previously dominated by H–E–P sediments. On the basis of the prevailing hydraulic regime, textural and mineralogical characteristics of the sediments, and hydrographic and bathymetric information from the region, a hypothetical sediment dynamics model for the delta region is proposed, in which the tidally influenced, wave-dominated, sediment-reworked, slightly eroding Sonoran coast changes into a tide-dominated, depositional, very slowly prograding Baja Californian coast. This study shows that human intervention of the hydrologic basin of the Colorado River is not only responsible for inducing drastic hydrologic changes in its estuary (i.e., from brackish to hypersaline), but also for inducing drastic changes in the hydrographic circulation of the receiving basin (i.e., from long-basinal to cross-basinal). These changes are ultimately responsible for the relocation of massive volumes of the delta's sediment inventory, and for the serious ecological impact of habitat loss of indigenous species, such as the now endangered Totoaba (Totoaba macdonaldi) and Vaquita (Phocoena sinus).

There has been a recent appreciation of the ecological impacts of zooplanktonic species invasions. The North American brine shrimp Artemia franciscana is one such alien invader in hyper-saline water ecosystems at a global scale. It has been shown to outcompete native Artemia species, leading to their local extinction. We used partial sequences of the mitochondrial Cytochrome c Oxidase Subunit 1 (COI or cox1) gene to investigate the genetic diversity and phylogeography of A. salina, an extreme halophilic sexual brine shrimp, over its known distribution range (Mediterranean Basin and South Africa) and to assess the extent of local endemism, the degree of population structure and the potential impact of traditional human saltpan management on this species. We also examined the phylogenetic relationships in the genus Artemia using COI sequences. Our results show extensive regional endemism and indicate an early Pleistocene expansion of A. salina in the Mediterranean Basin. Subsequent population isolation in a mosaic of Pleistocene refugia is suggested, with two or three refugia located in the Iberian Peninsula. Two instances of longdistance colonization were also observed. Surprisingly, given its strong phylogeographical structure, A. salina showed a signature of correlation between geographical and genetic distance. Owing to strong 'priority effects', extensive population differentiation is retained, despite dispersal via migrant birds and human management of saltpans. The foreseeable expansion of A. franciscana is likely to be followed by substantial loss of genetic diversity in Mediterranean A. salina. Large genetic divergences between Mediterranean and South African A. salina suggest that the latter deserves species status. Fig. 3 Statistical parsimony network showing the nested design used in NCPA. Only second (continuous thin line), third (continuous thick line) and statistically informative 1stlevel clades (discontinuous thin line) are shown. Sizes of ellipses are proportional to the number of individuals included (ellipses with numbers bottom left). The populations where each haplotype was found are shown next to the haplotype code. Lines linking haplotypes indicate single substitutions. Small black circles indicate missing haplotypes.

In recent years, artificial intelligence methods have demonstrated to be appropriated for treatment of environmental problems. This paper presents a novel work for assessment and prediction of the water quality in shrimp aquaculture based on environmental pattern processing. Water quality studies are based on analyzing negative concentrations of compounds in shrimp ponds that inhibit the good growing and reproduction of organism. The physical-chemical variables are classified basing on the negative ecological impact using the Gamma (Γ) classifier, which calculates the frequency and the deviation of the measurements from a specific level. A fuzzy inference system processes the level classifications using a reasoning process that determines when a specific concentration is good or harmful for the organism, and providing a water quality index, which describe the condition of the ecosystem: excellent, good, regular and poor. An autoregressive model (AR) predicts a section of an environmental signal using historical information, the set of predicted variables are assessed in order to estimate future water quality conditions in the system. This methodology emerges as a suitable and alternative tool to be used in the developing effective water management plans.

The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However, the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants was evaluated. Reference toxicants were rated in relation to the following criteria: (a) reproducibility, (b) low human health hazard, (c) feasibility of measurement, and (d) chemical stability. Potassium chloride (KCl) and ammonium chloride (NH,CI) were evaluated as possible alternatives to the one currently in common use, 2-chloroacetamide. Potassium chloride rated the best for the combination of the four criteria, followed by NH4C1 and 2-chloroacetamide. Coefficients of variation (C.V.s) from control charts of six definitive tests were used to measure reproducibility. The best reproducibility (lowest C.V.) was shown by KC1, followed by NH4C1 and 2-chloroacetamide. Toxicants ranked KCl < NH4C1 << 2-chloroacetamide in terms of health hazard; and KC1 = NH,Cl> 2-chloroacetamide in terms of measurement feasibility. Both 2-chloroacetamide and NH,Cl changed in concentration during testing. Evidence is also presented that 2-chloroacetamide degrades rapidly during testing, and that, as dead worms decay, ammonification may be adding another toxicant, ammonia, to tests.

Ziziphus mistol Griseb. (Rhamnaceae), popularly known as "mistol," is widely distributed throughout Perú, Bolivia, Paraguay and Argentina. Its fruit is consumed in different forms in several Argentinean communities. The aim of this work is to quantify Z. mistol fruit macronutrients and phytochemicals as well as to determine its functional antioxidant and anti-inflammatory properties and toxicity after two different processes: boiling and hydroalcoholic extraction. Phytochemical recovery was variable depending on the extraction method used. All preparations showed antioxidant activity, but the ethanolic one (EME) was significantly more active than the aqueous one (AME) as hydrogen or electron donors with SC 50 values between 1.45 to 6.31 μg GAE/ mL and 7.38 to 64.77 μg GAE/mL, respectively. The aqueous extraction was significantly more active than EME on superoxide and hydroxyl radical scavenging. Polyphenols showed a dose-response relationship (R 2 N 0.90) with antioxidant capacity in the decoction and the alcoholic beverage. The maceration showed an inhibitory effect on lipoxygenase (LOX) activity with an inhibitory concentration (IC 50) value of 183.80 μg gallic acid equivalents (GAE)/mL but the decoction did not. On the other hand, extracts did not show any mutagenic effect. Therefore, mistol fruits consumption could be encouraged not only for its functional properties, but also because of the positive ecological impact of preserving biological diversity through the exploitation of native natural resources in a regional economy.

Environmental indicators must have a predictable relationship with stressors to be of value in ecological assessments. We evaluated the information provided by commonly implemented monitoring indicators as a means of assessing of the level of ecological impact experienced by coastal lagoons in New South Wales, Australia. Existing data for environmental variables in coastal lagoons were correlated with independent estimates of catchment disturbance. There were few relationships between the monitoring variables (particularly water chemistry) and nutrient loads and catchment land use. Data from NSW catchments and lagoons were compared to analogous data from published northern hemisphere studies and it was clear that stressor variables were up to one to two orders of magnitude smaller in NSW, potentially explaining the lack of relationships with recognised indicators.Our study has highlighted the importance of using a range of indicators to assess trends in ecological condition of an estuarine ecosystem, particularly where stressor levels are not great. Using water quality as the sole means of determining lagoon condition was simply inadequate in NSW lagoons. We recommended that ecological outcome indicators such as algal abundance (macro and micro) and turbidity were most likely to show interpretable patterns at low to moderate nitrogen loadings (<40 kg Ha−1 yr−1) and that these should form the basis of estuarine trend monitoring in NSW lagoons. The demonstrated value of seagrass and macroalgal monitoring in estuaries with moderate to high nutrient loadings suggests that these indicators should not be overlooked when planning monitoring programs, recognising, however, they will not have strong discrimination at lower catchment loadings.

1. Detailed research into the ecological impacts of inter-basin water transfers (IBTs) is virtually nonexistent on a global scale. However, a growing awareness of the serious nature of such impacts—for example, the loss of biogeographical integrity, the loss of endemic biotas, the frequent introduction of alien and often invasive aquatic and terrestrial plants and animals, the genetic intermixing of once separated populations, the implications for water quality, the frequently drastic alteration of hydrological regimes, the implications for marine and estuarine processes, climatic effects, and the spread of disease vectors, amongst many others—demands a most urgent and world-wide appraisal of all current planning and research strategies.2. This paper first defines the types of extant IBTs, and details some case studies for three widely separated regions of the world, namely: south-eastern Australia, southern Africa, and the central and south-western parts of the United States of America. In doing so, it highlights the chronic paucity of ecological data on their impacts, while simultaneously emphasising their extreme complexities.3. Finally, we call for an international meeting on such schemes, as a matter of priority and extreme urgency, in order to assess the extent of IBTs, their geographical distribution, and their ecological and sociological impacts and implications.

A literature survey identified 403 primary research publications that investigated the ecological effects of invasive alien insects and/or the mechanisms underlying these effects. The majority of these studies were published in the last 8 years and nearly two-thirds were carried out in North America. These publications concerned 72 invasive insect species, of which two ant species, Solenopsis invicta and Linepithema humile, accounted for 18% and 14% of the studies, respectively. Most publications investigated effects on native biodiversity at population or community level. Genetic effects and, to a lesser extent, effects on ecosystem services and processes were rarely explored. We review the effects caused by different insect invaders according to: their ecosystem roles, i.e. herbivores, predators, parasites, parasitoids and pollinators; the level of biological organisation at which they occur; and the direct and indirect mechanisms underlying these effects. The best documented effects occur in invasive ants, Eurasian forest herbivores invasive in North America, and honeybees. Impacts may occur through simple trophic interactions such as herbivory, predation or parasitism. Alien species may also affect native species and communities through more complex mechanisms such as competition for resources, disease transmission, apparent competition, or pollination disruption, among others. Finally, some invasive insects, particularly forest herbivores and ants, are known to affect ecosystem processes through cascading effects. We identify biases and gaps in our knowledge of ecological effects of invasive insects and suggest further opportunities for research.

Developmental changes in river basins in Africa have become a reality. Many wetland ecosystems have been impacted by dams and other hydrological interventions resulting in both foreseen and unexpected consequences. The Kafue Flats in southern Zambia is an extensive floodplain system that lies within the middle Kafue river basin. The floodplain is about 255 km long and 60 km wide, covering an area of approximately 6,500 km 2 . It is currently sandwiched between two large dams which are approximately 270 km apart. These dams have completely altered the hydrological regime of the system. Backwater from the downstream dam and releases from upstream have created a permanently flooded area within the floodplain that was not present in the past. Elsewhere, flooding has been reduced. The ecological consequences of these changes for the floodplain, which hosts two national parks (both Ramsar sites), have been extensive. Hydrological and vegetation changes have impacted the habitat for important wildlife communities including the endemic antelope, Kobus leche kafuensis. The most dramatic change in vegetation is associated with the colonisation of parts of the floodplain by the invasive alien plant, Mimosa pigra. This paper discusses these changes and their potential consequences.

Pacifastacus leniusculus (Dana), a native crayfish of western North America, was introduced into the U.K. in 1976. Our study examined some interactions between P. leniusculus and benthic fish in a British lowland river, the River Great Ouse. In a river survey an inverse correlation was found between the abundance of crayfish and the two dominant benthic fishes, bullhead ( Cottus gobio L.) and stone loach ( Noemacheilus barbatulus [L.]) in six riffles. The benthic fishes were least abundant in the riffle nearest the original site of crayfish introduction and gradually increased in abundance both up and down river as crayfish abundance decreased. The hypotheses that crayfish compete with bullheads and stone loach for shelter and prey on fish were tested by laboratory experiments in an outdoor artificial stream (6 ϫ 2 m) with recirculating water and 12 artificial shelters on the bottom. In competition experiments 12 fish of one species were alternatively kept alone and with 12 crayfish for 3-day cycles lasting a total of 12 days. The results showed that crayfish outcompeted both fish species for shelter. Predation was measured by keeping 24 fish of each species alone and with 36 crayfish for 10 days respectively in the artificial stream. The mortalities of both fish species were significantly higher when crayfish were present. The loss of fish could be partly due to predation because crayfish guts contained the remains of some lost fish and they were observed preying on both fishes in a tank. In the river crayfish lived at high densities reaching Ն to 20 m Ϫ 2 in riffles, and they continued to disperse. This may lead to a great reduction in benthic fish abundance if not local extinctions.

The expansion of industrial oil palm cultivation threatens tropical biodiversity globally, especially in developing countries. Driven by plans to generate economic revenue, large-scale plantations are emerging in Southeast Asia, Africa and Brazilian Amazon. However, the ecological impacts of the sector are poorly studied with respect to oil palm management system, and recommended conservation measures are based on limited data. We studied avifauna in oil palm landscapes in Peninsular Malaysia under different management systems (large plantation estates versus smallholdings) and age classes (uniform age versus mixed-age stands). We sampled 41 large plantation estates and 14 smallholdings, as well as 20 sites in an extensively logged peat swamp forest, the type of natural forest prior to conversion to oil palms. Compared with logged peat swamp forest, our results showed that forest conversion to oil palm cultivation may have eliminated 48-60% of bird species. We also found: (i) plantation estates and smallholdings supported similar bird assemblages but the latter supported significantly more species (P = 0.007); and (ii) despite reduced species richness in oil palm landscapes, we found high abundance of some individual bird species in specific types of stands including some forest, migratory, and wetland species. Conversion of natural forest to oil palm landscapes should not occur in the future through clearing of primary or secondary native forests. To complement conventional conservation approaches (e.g. the establishment of protected areas) in palm oil-producing countries, existing plantation estates and smallholdings should be managed in ways to promote improved conservation outcomes, although oil palm landscapes maintained a fraction of the original forest biodiversity. Managing habitat heterogeneity at both a local and a landscape-level is highly recommended in oil palm landscapes to maintain and/or enhance avian biodiversity.

Biofouling increases drag on marine vessels resulting in higher fuel consumption and can also facilitate the transport of harmful non-indigenous species (NIS). Antifouling technologies incorporating biocides (e.g., copper and tributyltin) have been developed to prevent settlement of organisms on vessels, but their widespread use has introduced high levels of contamination into the environment and raised concerns about their toxic effects on marine communities. The recent global ban on tributyltin (1 January 2008) and increasing regulation of copper have prompted research and development of non-toxic paints. This review synthesises existing information regarding the ecological impact of biocides in a wide range of organisms and highlights directions for the management of antifouling paints. We focus particularly on representatives of the recent past (copper and tributyltin) and present (copper and 'booster') biocides. We identify knowledge gaps in antifouling research and provide recommendations relating to the regulation and phasing-out of copper.

The Green Revolution in India has achieved self-sufficiency in food production. However, in the state of Haryana this has resulted in continuous environmental degradation, particularly of soil, vegetation and water resources. Soil organic matter levels are declining and the use of chemical inputs is intensifying. Newly introduced crop varieties have been responsive to inputs but this has necessitated both increased fertiliser application and use of irrigation resulting in water contamination by nitrate and phosphate and changes in the ground water table. With 82% of the geographic area already under cultivation, the scope for increased productivity lies in further intensification which is crucially dependent on more energy-intensive inputs. Declining nutrient-use efficiency, physical and chemical degradation of soil, and inefficient water use have been limiting crop productivity, whilst the use of monocultures, mechanisation and an excessive reliance on chemical plant protection have reduced crop, plant and animal diversity in recent years. About 60% of the geographical area faces soil degradation (waterlogging, salinity and alkalinity) which threatens the region's food security in the future. Since 1985, the water table has risen more than 1 m annually, and patches of salinity have started to appear at the farm level. The situation is worse in higher rainfall areas where waterlogging follows shortly after the rains. Apart from affecting agricultural crops, a high water table causes floods even following slight rains due to the reduced storage capacity of the soil. Such ecological impacts are motivating farmers to reduce fertiliser and pesticides use. This has led to an increased investment in alternative technology and products including an interest in Integrated Pest Management. The paper discusses major physical, hydrological, chemical and biological constraints relating to soil and water resources for ecosystem sustainability. : S 0 1 6 7 -8 8 0 9 ( 0 0 ) 0 0 2 1 9 -X

This paper reviews recent research into the ecological impacts of recreation and tourism on coastal marine fauna in Australia. Despite the high and growing importance of water-based recreation to the Australian economy, and the known fragility of many Australian ecosystems, there has been relatively limited research into the effects of marine tourism and recreation, infrastructure and activities, on aquatic resources. In this paper we have reviewed the ecological impacts on fauna that are caused by outdoor recreation (including tourism) in Australian coastal marine ecosystems. We predict that the single most potentially severe impact of recreation may be the introduction and/or dispersal of nonindigenous species of marine organisms by recreational vessels. Such introductions, together with other impacts due to human activities have the potential to increasingly degrade recreation destinations. In response, governments have introduced a wide range of legislative tools (e.g., impact assessment, protected area reservation) to manage the recreational industry. It would appear, however, that these instruments are not always appropriately applied.

The relationship between density of development and the health of nearshore marine habitats is explored through spatial and temporal comparisons of patch reef environments in the central Bahamas. Nearshore patch reefs are important fi sh habitats, and tend to have high, but variable, coral cover and benthic diversity in the Bahamian archipelago. Twelve patch reef stations were established off developed and undeveloped islands in the central Bahamas. Environmental parameters were measured over an 18-mo period to examine seasonal, tidal, and diurnal variability. Water quality measurements were not signifi cantly different between developed and undeveloped sites for temperature, salinity, dissolved oxygen, chlorophyll-a, total nitrogen and total phosphorus. Only turbidity measurements were signifi cantly different among sites, attributed to storm events. Ecological surveys recorded macroalgae species, stony coral species, coral cover, and coral vitality. Signifi cant differences in species composition between developed and undeveloped stations were seen, with a higher coral diversity, lower coral cover, and higher incidence of coral lesions on developed patch reefs. A 53yr comparison of nearshore environments from aerial imagery showed signifi cant loss of patch reefs and seagrass areas with increasing development density. Results stress the importance of comparison reefs in marine protected areas for evaluating impacts of coastal development on nearshore marine habitats.

Dam removal continues to garner attention as a potential river restoration tool. The increasing possibility of dam removal through the FERC relicensing process, as well as through federal and state agency actions, makes a critical examination of the ecological benefits and costs essential. This paper reviews the possible ecological impacts of dam removal using various case studies. Restoration of an unregulated flow regime has resulted in increased biotic diversity through the enhancement of preferred spawning grounds or other habitat. By returning riverine conditions and sediment transport to formerly impounded areas, riffle/pool sequences, gravel, and cobble have reappeared, along with increases in biotic diversity. Fish passage has been another benefit of dam removal. However, the disappearance of the reservoir may also affect certain publicly desirable fisheries. Short-term ecological impacts of dam removal include an increased sediment load that may cause suffocation and abrasion to various biota and habitats. However, several recorded dam removals have suggested that the increased sediment load caused by removal should be a short-term effect. Preremoval studies for contaminated sediment may be effective at controlling toxic release problems. Although monitoring and dam removal studies are limited, a continued examination of the possible ecological impacts is important for quantifying the resistance and resilience of aquatic ecosystems. Dam removal, although controversial, is an important alternative for river restoration.

... Keywords: Strawbale building, Construction, Risks, Moisture, Ecological impacts, Fire safety, Mould growth Introduction Straw has been used as a building material since prehistoric times, as a component of roofs; in structural walls; and as an insulation material. ...

The ecotourism literature is focused on market segmentation, ecological impacts of wildlife viewing, and community-based ecotourism, but there has been minimal attention to critical areas such as quality control, the industry, external environments or institutions even as the components and parameters of ecotourism are being extended. This imbalance, combined with the fragmentation and lack of integration within the literature, suggest that ecotourism, as a field of academic inquiry, is still in a state of adolescence. r

The increase of productivity in aquaculture has been accompanied by ecological impacts including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in production cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in aquaculture, with a critical evaluation of results obtained to date. #

We review direct and indirect impacts of invasive alien species (focussing on plants and insects) on native bees worldwide. Although there is a rapidly growing body of research into the effects of invasive alien plants on native plant pollination via disruption of native mutualisms, there has been little research on the impacts of invasive alien plants directly on bees. Such impacts are likely to vary according to the taxon of plant, the functional specificity of the native bees, and ecosystem context. Conversely, there have been more attempts to document impacts of invasive alien social bees on native bees. Most of these studies only indirectly evaluate competition for resources, have focused on a few native species and findings are sometimes contradictory. However, some studies showed strong negative impacts, suggesting that effects might be species-specific. Additionally, pathogen spillover and reproductive disruption due to interspecific mating has been demonstrated among some closely related taxa. Where we lack unequivocal evidence for impacts however, this should not be interpreted as lack of effect. We recommend that future studies are robustly designed and consider impacts on genetic, species (particularly solitary bees) and ecosystem biodiversity.

The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aquaculture systems (RASs) provide opportunities to reduce water usage and to improve waste management and nutrient recycling. RAS makes intensive fish production compatible with environmental sustainability. This review aims to summarize the most recent developments within RAS that have contributed to the environmental sustainability of the European aquaculture sector. The review first shows the ongoing expansion of RAS production by species and country in Europe. Life cycle analysis showed that feed, fish production and waste and energy are the principal components explaining the ecological impact of RAS. Ongoing developments in RAS show two trends focusing on: (1) technical improvements within the recirculation loop and (2) recycling of nutrients through integrated farming. Both trends contributed to improvements in the environmental sustainability of RAS. Developments within the recirculation loop that are reviewed are the introduction of denitrification reactors, sludge thickening technologies and the use of ozone. New approached towards integrated systems include the incorporation of wetlands and algal controlled systems in RAS. Finally, the review identifies the key research priorities that will contribute to the future reduction of the ecological impact of RAS. Possible future breakthroughs in the fields of waste production and removal might further enhance the sustainabilty of fish production in RAS.

Plant roots serve a multitude of functions in the plant including anchorage, provision of nutrients and water, and production of exudates with growth regulatory properties. The root-soil interface, or rhizosphere, is the site of greatest activity within the soil matrix. Within this matrix, roots affect soil structure, aeration and biological activity as they are the major source of organic inputs into the rhizosphere, and are also responsible for depletion of large supplies of inorganic compounds. Roots are very complicated morphologically and physiologically, and their metabolites are often released in large quantities into the soil rhizosphere from living root hairs or fibrous root systems. Root exudates containing root-specific metabolites have critical ecological impacts on soil macro and microbiota as well as on the whole plant itself. Through the exudation of a wide variety of compounds, roots impact the soil microbial community in their immediate vicinity, influence resistance to pests, support beneficial symbioses, alter the chemical and physical properties of the soil, and inhibit the growth of competing plant species. In this review, we outline recent research on root exudation and the role of allelochemicals in the rhizosphere by studying the case of three plants that have been shown to produce allelopathic root exudates: black walnut, wheat and sorghum

During field surveys from June 2002 through August 2003, we documented an established population of the veiled or Yemen chameleon (Chamaeleo calyptratus) in Fort Myers, Lee County, Florida. We recorded at least 70 individuals, including both genders and all size classes in consecutive years, indicating a reproducing population. Additionally, ca. 100 individuals were reportedly removed from this site prior to our study. Chamaeleo calyptratus has also been reported from areas near Lehigh Acres and Alva, Lee County, and Naples, Collier County, suggesting independent introductions of this popular exotic lizard. Monitoring of this population should continue, and eradication should be attempted if ecological impacts on native species are observed.

Ichthyofauna in the Hellenic freshwaters is quite diverse consisted of 161 species (including 28 non-natives), out of the 546 native species in Pan-European level. However, the status of many aquatic ecosystems is currently degraded as a result of a variety of anthropogenic impacts. This has direct reflection on the conservation status of the indigenous and native fish species whose populations are in many cases declining in favor of the invasive ones. Prussian carp (Carassius gibelio) is probably the most dominant invasive species and currently is considered as naturalized in about 26 lake and river basins. Its successful adaptation and proliferation is mainly attributed to its dual reproductive mode (allogynogenetic and gonochoristic), the opportunistic-omnivorous feeding habits and the ability to withstand and flourish in adverse ecological conditions. Accordingly, it exerts competitive, as well as destructive effects upon the indigenous fish species (sperm parasitism, antagonism for food, spawning grounds and spawning substrates) and therefore, efforts are needed to sustain a relative balance of the populations. This review aims to critically discuss the status of C. gibelio in Greece, the intrinsic causes of establishment and the observed impacts on ecosystems. Finally, reasonable actions are proposed related to exploitation of C. gibelio stocks and a path model for the protection of native fish species and their ecosystems.

The increase of productivity in aquaculture has been accompanied by ecological impacts including emergence of a large variety of pathogens and bacterial resistance. These impacts are in part due to the indiscriminate use of chemotherapeutic agents as a result of management practices in production cycles. This review provides a summary of the use of probiotics for prevention of bacterial diseases in aquaculture, with a critical evaluation of results obtained to date. #

The Red Sea is a deep semi-enclosed and narrow basin connected to the Indian Ocean by a narrow sill in the south and to the Suez Canal in the north. Oil industries in the Gulf of Suez, phosphate ore mining activities in Safaga-Quseir region and intensified navigation activities are non-nuclear pollution sources that could have serious radiological impacts on the marine environment and the coastal ecosystems of the Red Sea. It is essential to establish the radiological base-line data, which does not exist yet, and to investigate the present radio-ecological impact of the non-nuclear industries to preserve and protect the coastal environment of the Red Sea. Some natural and man-made radionuclides have been measured in shore sediment samples collected from the Egyptian coast of the Red Sea. The specific activities of 226 Ra and 210 Pb ( 238 U) series, 232 Th series, 40 K and 137 Cs (Bq/kg dry weight) were measured using gamma ray spectrometers based on hyper-pure germanium detectors. The specific activities of 210 Po ( 210 Pb) and uranium isotopes ( 238 U, 235 U and 234 U) (Bq/kg dry weight) were measured using alpha spectrometers based on surface barrier (PIPS) detectors after radiochemical separation. The absorbed radiation dose rates in air (nGy/h) due to natural radionuclides in shore sediment and radium equivalent activity index (Bq/kg) were calculated. The specific activity ratios of 228 Ra/ 226 Ra, 210 Pb/ 226 Ra, 226 Ra/ 238 U and 234 U/ 238 U were calculated for evaluation of the geo-chemical behaviour of these radionuclides. The average specific activity of 226 Ra ( 238 U) series, 232 Th series, 40 K and 210 Pb were 24.7, 31.4, 427.5 and 25.6 Bq/kg, respectively. The concentration of 137 Cs in the sediment samples was less than the lower limit of detection. The Red Sea coast is an arid à Corresponding author. Present address: region with very low rainfall and the sediment is mainly composed of sand. The specific activity of 238 U, 235 U and 234 U were 25.3, 2.9 and 25.0 Bq/kg. The average specific activity ratios of 226 Ra/ 228 Ra, 210 Pb/ 226 Ra and 234 U/ 238 U were 1.67, 1.22 and 1.0, respectively.

The genus Castor comprises two species: the Eurasian beaver Castor fibre , and the North American beaver Castor canadensis . Both species suffered from overexploitation, but have seen a revival since the 1920s due to increased protection and reintroduction programmes. Increases in the populations and distributions of species that are able to modify ecosystems have generated much scientific interest. Here

Historically, visitors' motives for visiting protected areas included 'rest, relaxation and reinvigoration'. Ecological impacts were typically low. Recent trends have increased use of protected areas for extreme sports, with greater numbers undertaking more active recreation, such as extreme sports. The effect of this trend is considered, together with potential management options. We propose that the development of appropriately targeted and delivered educational programmes could minimise environmental degradation. However, to maximise ecological conservation in protected lands we consider that a major paradigm shift is required. This will require a more strategic, holistic approach to planning and managing outdoor recreation/sport destinations incorporating collaboration across stakeholders. Based on past experience, to continue with the current model will ultimately accelerate biodiversity loss, degradation of protected areas, and loss of recreational amenity.