Rising food, housing and energy demand of increasing population creates an immense pressure on water resources, especially on water quality. The water quality around the globe is degrading primarily due to intense agricultural activities associated with rapid urbanization. This study attributes to cause of water quality problem, indices to measure water quality, methods to identify proper explanatory variables to water quality and it's processing to capture the special effect, and finally modeling of water quality using identified explanatory variables to provide insights. This would help policymakers and watershed managers to take necessary steps to protect water quality for the future as well as current generation. Finally, some knowledge gaps are also discussed which need to be addressed in the future studies.
This paper elaborates an empirical analysis of labour force characteristics that emerge as a response to the growing importance of environmental sustainability. Using data on the United States we compare green and non-green occupations to detect differences in terms of skill content and of human capital. Our empirical profiling reveals that green jobs use more intensively high-level cognitive and interpersonal skills compared to non-green jobs. Green occupations also exhibit higher levels of standard dimensions of human capital such as formal education, work experience and on-the-job training. While preliminary, our exploratory exercise seeks to call attention to an underdeveloped theme, namely the labour market implications associated with the transition towards green growth.
An abundance of approaches, strategies, and instruments – in short: tools – have been developed that intend to stimulate or facilitate the integration of a variety of environmental objectives into development planning, national or regional sectoral policies, international agreements, business strategies, etc. These tools include legally mandatory procedures, such as Environmental Impact Assessment and Strategic Environmental Assessment; more voluntary tools such as environmental indicators developed by scientists and planning tools; green budgeting, etc. A relatively underexplored question is what integration tool fits what particular purposes and contexts, in short: “what works where?”. This paper intends to contribute to answering this question, by first providing conceptual clarity about what integration entails, by suggesting and illustrating a classification of integration tools, and finally by summarising some of the lessons learned about how and why integration tools are (not) used and with what outcomes, particularly in terms of promoting the integration of environmental objectives.
Baited stereo-camera surveys of fish assemblages provide conservative estimates of abundance and length-frequency distributions. While underwater camera systems have numerous advantages over traditional fishing and diver surveys, limitations in sampling capacity, data processing time, and resultant data still exist. Previous studies have shown that shorter camera soak times can increase sampling efficiency and reduce per-sample data processing time without affecting overall data quality. Using data from stereo-video surveys of bottomfish in the main Hawaiian Islands, this study evaluates the effect of camera soak time on relative abundance metrics, fish length data, sampling efficiency, and power to detect differences in relative abundance and fish lengths. A soak time of 15 min was found to be the shortest duration able to capture bottomfish abundance and length metrics while 30 min generated data that did not significantly differ from the standard 40-min soak time. These shorter soak times allow for better survey efficiency and improved cost–benefit through increased levels of field sampling and reductions in video-processing time, while maintaining the power to detect differences in bottomfish relative abundance and lengths. The main drawback to shortening soak time was the concurrent reduction in the number of length measurements collected per species. An increased sample yield can alleviate this effect but only for bottomfish with a higher frequency of occurrence. Species-specific patterns in abundance were apparent in this study suggesting a strong influence of fish behavior on stereo-video abundance metrics. While a soak time of 15 to 30 min was found to be sufficient for effectively sampling bottomfish, the cost–benefit of employing a given soak time in future stereo-video surveys should be assessed based on the target species and survey goals.
The Antarctic Treaty permits the discharge of wastewater into Antarctic marine waters providing that conditions exist for initial dilution and rapid dispersal. We investigated the dilution and dispersal of macerated wastewater around Australia's Davis Station in East Antarctica and examined sediments for evidence of contaminants. Methods used to examine hydrodynamic conditions included current meters, dye release experiments and measurement of sewage-associated microbial markers and surfactants in the water column. We measured marine sediments for metals, nutrients, PBDEs, hydrocarbons and faecal sterols. We propose that if there is adequate dilution and dispersal there would be no significant difference in contaminant concentrations in sediments around the outfall compared to distant control sites. Currents were strongly correlated with prevailing wind conditions. Modelling indicated that diffusivity of wastewater had the greatest effect on dilution factors and that neither discharge rates nor local currents had as much effect. During summer conditions of open water, wastewater is likely to be constrained in a narrow plume close to the coast. Concentrations of sewage bacteria were high around the outfall and detected up to 1.5 km away, along with dye. There were significant differences in sediment concentrations of metals, PBDEs, hydrocarbons, nutrients and faecal sterols between sites within 2 km of the outfall and control sites. We conclude that dilution and dispersal conditions at the Davis outfall are insufficient to prevent the accumulation of contaminants in local sediments and that microbial hazards posed by wastewater are an environmental risk to local wildlife.
Hydrothermal vent fields in the western Pacific Ocean are mostly distributed along spreading centers in submarine basins behind convergent plate boundaries. Larval dispersal resulting from deep-ocean circulations is one of the major factors influencing gene flow, diversity, and distributions of vent animals. By combining a biophysical model and deep-profiling float experiments, we quantify potential larval dispersal of vent species via ocean circulation in the western Pacific Ocean. We demonstrate that vent fields within back-arc basins could be well connected without particular directionality, whereas basin-to-basin dispersal is expected to occur infrequently, once in tens to hundreds of thousands of years, with clear dispersal barriers and directionality associated with ocean currents. The southwest Pacific vent complex, spanning more than 4,000 km, may be connected by the South Equatorial Current for species with a longer-than-average larval development time. Depending on larval dispersal depth, a strong western boundary current, the Kuroshio Current, could bridge vent fields from the Okinawa Trough to the Izu-Bonin Arc, which are 1,200 km apart. Outcomes of this study should help marine ecologists estimate gene flow among vent populations and design optimal marine conservation plans to protect one of the most unusual ecosystems on Earth.
Mixotrophic plankton, which combine the uptake of inorganic resources and the ingestion of living prey, are ubiquitous in marine ecosystems, but their integrated biogeochemical impacts remain unclear. We address this issue by removing the strict distinction between phytoplankton and zooplankton from a global model of the marine plankton food web. This simplification allows the emergence of a realistic trophic network with increased fidelity to empirical estimates of plankton community structure and elemental stoichiometry, relative to a system in which autotrophy and heterotrophy are mutually exclusive. Mixotrophy enhances the transfer of biomass to larger sizes classes further up the food chain, leading to an approximately threefold increase in global mean organism size and an ∼35% increase in sinking carbon flux.
A choice experiment is undertaken to elicit preferences of scuba divers in the Marine Protected Area of Medes Islands (Spain). This is the first non-market valuation study of a typical Mediterranean habitat, the Coralligenous, which is characterized by high biodiversity, geomorphologic complexity and iconic species like gorgonians. This habitat is not only very attractive for scuba diving, but is also threatened by climate change and ocean acidification, which is our motivation for undertaking this valuation study. Choice attributes include the number of divers on a diving trip, underwater landscape, presence of jellyfish species, expected state of gorgonians, and price of a dive. Results of multinomial and random parameter logit models indicate a decrease in the attractiveness of Coralligenous areas for scuba diving as a result of both environmental pressures. Estimates of welfare values show that the local extinction of gorgonians had the highest negative effect on utility equivalent to a cost of €60 per dive, followed by abundance of stinging jellyfish with a cost of €26 per dive. Choice probabilities for the selection of different dive experiences indicate the highest rejection rates for the combined sea warming and acidification scenarios.
- Data sets on wetlands required for the representation of aquatic ecosystem biodiversity and systematic wetland conservation planning are typically not available or are inadequate, particularly at country-wide scale, which hinders conservation planning. The improvement in hierarchical classification systems and increased availability of broad-scale data sets offers new opportunities to overcome these limitations.
- This study demonstrates replicable methods for classifying wetland ecosystem types and condition country-wide using broad-scale data sets in data-scarce countries.
- A country-wide data set, compiled primarily using remote sensing techniques, was combined with regional and landscape-setting data sets to reflect the ecological and geomorphic biodiversity of wetlands. Geographical Information Systems (GIS) were employed to model wetland types, disturbance indices and identify priority wetlands through threatened faunal species associations using existing data. Accuracy of the national data was assessed through a congruency with two local data sets.
- Most of the 1 680 306 ha of inland wetlands were classified as Natural (80%), of which the majority were located on Valley Floors (68%). However, the national data were found only to represent 54% of wetlands mapped at a local scale, and comparison with local data showed inaccuracies in the types and condition classifications.
- Problems regarding spatial data quality and scale are discussed and suggestions for improvement are provided. The desktop classification steps can be reproduced easily for other data-scarce countries. Data sets on freshwater ecosystems can assist in raising awareness and influence policy at a national scale.
Over recent years, fisheries managers have been going through a paradigm shift to prioritize ecosystem-based management. With this comes an increasing need to better understand the impacts of fisheries management decisions on the social well-being and sustainability of fishing communities. This article summarizes research aimed at using secondary data to develop socioeconomic and fisheries involvement indices to measure objective fishing community well-being in Alaska. Data from more than 300 communities in Alaska were used to create a database of socioeconomic and fisheries involvement indices of objective well-being and adaptability for Alaska communities dependent on marine resources. Each index was developed using a principal components factor analysis to assess the relative position of each community compared to all other communities in Alaska. We find that creating performance measures, such as the indices presented here, provides a useful way to track the status of socioeconomic conditions and fisheries involvement by communities over time.