The Estuarine Component of the Us E.P.A.'S Environmental Monitoring and Assessment Program

The US Environmental Protection Agency's Office of Research and Development has initiated the Environmental Monitoring and Assessment Program (EMAP) to monitor status and trends in the condition of the nation's near coastal waters, forests, wetlands, agro-ecosystems, surface waters, deserts and rangelands. the programme is also intended to evaluate the effectiveness of Agency policies at protecting ecological resources occurring in these systems. Monitoring data collected for all ecosystems will be integrated for regional and national status and trends assessments. the near coastal component of EMAP consists of estuaries, coastal waters, and the Great Lakes. Near coastal ecosystems have been regionalized and classified, and an integrated sampling strategy has been developed. EPA and NOAA have agreed to coordinate and, to the extent possible, integrate the near coastal component of EMAP with the NOAA National Status and Trends Program. A demonstration project was conducted in estuaries of the mid-Atlantic region (Chesapeake Bay to Cape Cod) in the summer of 1990. in 1991, monitoring continued in mid-Atlantic estuaries and was initiated in estuaries of a portion of the Gulf of Mexico. Preliminary results indicate: there are no insurmountable logistical problems with sampling on a regional scale; several of the selected indicators are practical and sensitive on the regional scale; and an efficient effort in future years will provide valuable information on condition of estuarine resources at regional scales.     

Variance estimation in the EMAP strategy for sampling discrete ecological resources

The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) is designed to describe status, trends and spatial pattern of indicators of condition of the nation's ecological resources. The proposed sampling design for EMAP is based on a triangular systematic grid and employs both variable probability and double sampling. The Horvitz-Thompson estimator provides the foundation of the design-based estimation strategy used in EMAP. However, special features of EMAP designed to accommodate the complexity of sampling environmental resources on a national scale require modifications of standard variance estimation procedures as well as development of new techniques. An overview of variance estimation methods proposed for application to EMAP's sampling strategy for discrete resources is presented.     

Model-based combination of spatial information for stream networks

Evolutionary improvements in Geographic Information Systems (GIS) now routinely allow the management and mapping of spatial-temporal information. In response, the development of statistical models to combine information of different types and spatial support is of vital importance to environmental science. In this paper we develop a hierarchical spatial statistical model for environmental indicators of stream and river systems in the United States Mid-Atlantic Region by combining information from separate monitoring surveys, available contextual information on hydrologic units and remote sensing information. These models are used to estimate the indicators throughout the riverine system based on information from multiple sources and aggregate scales. The analysis is based on information underlying the Landscape Atlas of the mid-Atlantic region produced by the US Environmental Monitoring and Assessment Program (EMAP). We also combine information from two overlapping separate monitoring surveys, the EMAP Stream and River Survey and the Maryland Biological Streams Survey. We present a general framework for comparative distributional analysis based on the concept of a relative spatial distribution. As an application, the spatial model is used to predict spatial distributions and relative spatial distributions for a watershed.     

Coastal lagoons: “transitional ecosystems” between transitional and coastal waters

The European Water Framework Directive (WFD) establishes a well differentiated typology of water bodies on the basis of scientific and biological criteria. For coastal waters, such criteria have long been established, while for transitional waters they are still under discussion. One of the difficulties when applying the WFD to coastal lagoons is to include them in only one of these categories, and while there is no doubt about the nature of estuaries as transitional waters, there is some controversy concerning lagoons. To what extent, reference conditions may be similar for estuaries and lagoons, or whether features common to all coastal lagoons are more important for differentiating them from other water bodies than the fact that there is (or is not) any fresh water influence, is something that remains unclear and is discussed in this work. Coastal lagoons and estuaries form part of a continuum between continental and marine aquatic ecosystems. Shelter, strong boundaries or gradients with adjacent ecosystems, anomalies in salinity regarding freshwater or marine ecosystems, shallowness, etc. all contribute to the high biological productivity of estuaries and lagoons and determine common ecological guilds in the species inhabiting them. On the other hand, fresh water influence, the spatial organization of gradients and environmental variability (longitudinal one-dimensional gradients in estuaries versus complex patterns and three-dimensional heterogeneity in lagoons) constitute the main differences, since these factors affect both the species composition and the dominance of certain ecological guilds and, probably, the system’s complexity and homeostatic capability. In the context of the WFD, coastal lagoons and estuaries are closer to each other than they are to continental or marine waters, and, on the basis of the shared features, they could be intercalibrated and managed together. However, coastal lagoons cannot be considered transitional waters according to the present definition. To assume that fresh water influence is an inherent characteristic to these ecosystems could lead to important changes in the ecological organization and functioning of coastal lagoons where natural fresh water input is low or null. In our opinion, the present day definition of transitional waters should be changed substituting the criterion of fresh water influence by another based on common features, such as relative isolation and anomalies in salinity in water bodies with marine influence. Otherwise, coastal lagoons should be considered a particularly characteristic type of water mass for establishing reference conditions of ecological status.     

Dissolved nutrient dynamics along the southwest coastal waters of India during northeast monsoon: a case study

Dissolved nutrients, Chl-a and primary productivity were measured from seven transects along the coastal waters of the southeastern Arabian Sea during northeast monsoon. Ten major estuaries were chosen to study the influence of estuarine discharge on the nutrient dynamics in the coastal waters. The mean water discharge of the estuaries in the north (64.8?±?18?×?10⁵?m³?d^?1) was found to be higher than those in the south (30.6?±?21.4?×?10⁵?m³?d^?1), whereas the nutrient concentrations were found to be higher in the estuaries of the south. The results from the offshore waters were discussed in accordance with the depth contour classification, that is, shelf (depth?≤?30?m) and slope waters (depth?≥?30?m). Our results suggest that the estuarine discharge plays a major role in the nutrient distribution in near shore shelf waters, whereas in shelf and slope waters, it was mainly controlled by in situ biological processes. The inorganic form of N to P ratios were found to be higher than Redfield ratio in slope waters when compared with shelf waters, suggesting that PO₄^3? (<0.15?µmol?L^?1) is a limiting nutrient for primary production. The multivariate statistical analysis revealed that the nutrient dynamics in the coastal waters was controlled by both biological and physical processes.     

Bimetallic adsorbents for wastewater treatment: a review

Environmental Chemistry Letters - The rising pollution of water resources is threatening the health of humans and ecosystems, calling for advanced methods to clean polluted waters. Adsorption on...     

Self-purification capacity and management of Baltic coastal ecosystems

It is expected that the Baltic region becomes a major centre of economic growth and prosperity in Europe already during this decade (Anon. 2000). Therefore, an Agenda 21 for the Baltic region (Baltic 21) was developed to ensure a sustainable development. Especially the coastal ecosystems are subject to increasing anthropogenic pressure e.g. eutrophication, traffic, harbours, tourism or offshore wind parks. Eutrophication remains the main ecological problem in the Baltic Sea and has serious negative social and economical consequences. Inner and outer coastal waters play an important role as buffers and filters for the Baltic proper. Consequently, the utilization and preservation of their self-purification capacity is of great importance. Combined results of our own coastal research and of the international workshop ‘Baltic coastal ecosystems: structure, function and coastal zone management’ (Rostock University, November 2001) are presented here. Conclusions for an improved integrated coastal zone management of Baltic coastal ecosystems will be presented.     

Toxiwasp∗

TOXIWASP combines most of the kinetic structure of EXAMS 2 with the transport capabilities of WASP (Water Analysis Simulation Program). TOXIWASP uses variable chemical degradation rates from chemical properties and the environmental conditions of the aquatic ecosystem. These rates are reduced from pseudo first‐order rates to first‐order rates including the processes hydrolysis, biotransfor‐mation, phototransformation, oxidation, and volatilisation. Assuming ultimate local equilibrium, and using a chemical dependent partition coefficient as well as spatially varying environmental carbon fractions, sorption onto sediments and biomass is calculated. Environmental alternations could be specified in any time scale by providing monitoring data.

TOXIWASP generates total sediment and chemical concentrations every time step in every segment, including surface water, subsurface water, surface bed and subsurface bed. Advection, dispersion, mass loading, sedimentation, and scour affect sediment concentration in the water column and in the bed sediment concentrations depend on burial and erosion. In addition chemical concentrations are influenced by degradation, sediment‐water dispersion, and percolation. Lateral transport of chemical within the bed is neglected and transport data are not calculated in the program. TOXIWASP is developed to model stratified lakes, reservoirs, large rivers, estuaries, and coastal waters. As for EXAMS 2 (Burns et al.²) the TOXIWASP user has to accept the model's inability to connect the water body to a chemically contaminated atmosphere.     

Estuarine management strategies and the predictability of ecosystem changes

The Dutch Delta Region (S-W Netherlands) originally consisted of interconnected estuaries, interfacing the rivers Rhine, Meuse and Schelde with the North Sea. The ecosystems were immature, with physical rather than biological control of population dynamics. Main functions were shipping and shellfisheries. An emergent function of the interconnected estuaries was the buffering and upgrading of river-borne substances before they entered the sea. Execution of the Delta Project in the period 1960–1986 resulted in isolation of several water systems disconnected from rivers and sea, and loss of gradients within these systems. Population dynamics were now controlled by chemical and biological rather than physical factors. Vulnerability to external perturbation increased. These changes also affected the buffering capacity, i.e. reduced the utility of the area as stabiliser of the geosystem. Recreational use and appreciation of natural values increased, potentially conflicting with shipping and shellfisheries. Retrospective analysis of the environmental policy and management revealed three consecutive strategies in the Delta Project. 1. Reactive one-issue management, focusing on safety against flooding only. This strategy aimed at complete closure of the estuaries thus transforming them into fresh water lakes. It has destroyed feed-backs and buffering between coastal and inland waters. This strategy has not promoted sustainable development and has increased the vulnerability of the area to future catastrophes. 2. Protective bio-ecological management focused on the preservation of existing values of landscape and environment, and resulted in the maintenance of saline conditions and preservation of marshes by shore protection measures. The drawback of this passive orientation to existing values ?where they are now? is the necessity of continuous intensive care because the natural adaptive ability is not being restored. 3. Constructive geo-ecological management is based on understanding functional properties within and between ecosystems as integrated elements of the landscape structure. This strategy aims at environmental protection, restoration and development of values ?where they must be?. Re-establishment of gradients by e.g. re-introducing tidal influence and by restoring salt marshes should contribute to sustainable development.     

Denitrification across landscapes and waterscapes: a synthesis.

Denitrification is a critical process regulating the removal of bioavailable nitrogen (N) from natural and human-altered systems. While it has been extensively studied in terrestrial, freshwater, and marine systems, there has been limited communication among denitrification scientists working in these individual systems. Here, we compare rates of denitrification and controlling factors across a range of ecosystem types. We suggest that terrestrial, freshwater, and marine systems in which denitrification occurs can be organized along a continuum ranging from (1) those in which nitrification and denitrification are tightly coupled in space and time to (2) those in which nitrate production and denitrification are relatively decoupled. In aquatic ecosystems, N inputs influence denitrification rates whereas hydrology and geomorphology influence the proportion of N inputs that are denitrified. Relationships between denitrification and water residence time and N load are remarkably similar across lakes, river reaches, estuaries, and continental shelves. Spatially distributed global models of denitrification suggest that continental shelf sediments account for the largest portion (44%) of total global denitrification, followed by terrestrial soils (22%) and oceanic oxygen minimum zones (OMZs; 14%). Freshwater systems (groundwater, lakes, rivers) account for about 20% and estuaries 1% of total global denitrification. Denitrification of land-based N sources is distributed somewhat differently. Within watersheds, the amount of land-based N denitrified is generally highest in terrestrial soils, with progressively smaller amounts denitrified in groundwater, rivers, lakes and reservoirs, and estuaries. A number of regional exceptions to this general trend of decreasing denitrification in a downstream direction exist, including significant denitrification in continental shelves of N from terrestrial sources. Though terrestrial soils and groundwater are responsible for much denitrification at the watershed scale, per-area denitrification rates in soils and groundwater (kg N x km(-2) x yr(-1)) are, on average, approximately one-tenth the per-area rates of denitrification in lakes, rivers, estuaries, continental shelves, or OMZs. A number of potential approaches to increase denitrification on the landscape, and thus decrease N export to sensitive coastal systems exist. However, these have not generally been widely tested for their effectiveness at scales required to significantly reduce N export at the whole watershed scale.     

Hydrography and distribution dynamics of larval and juvenile fishes in the coastal waters of the Tanshui River estuary,Taiwan, with reference to estuarine larval transport

Distribution dynamics of fish larvae and juveniles in the coastal waters of the Tanshui River, Taiwan was studied fortnightly using surface horizontal tows with a larval net in daytime during the period from early April through early June 1991. Environmental factors, including water temperature, salinity, dissolved oxygen, pH, transparency and depth at sampling stations, were also monitored. A total of 10737 fish eggs and 1387 individuals, representing 43 families and 93 species, was collected during five cruises from 12 stations in the coastal waters. Most fish were estuarine-dependent marine species. Liza macrolepis, Ambassis gymnocephalus, Terapon jarbua, Mullidae and Gobiidae were the most dominant, making up 64.7% of the total catch. Early life stages, including egg, preflexion, flexion and postflexion larvae were abundant in surface samples. However, yolk-sac larvae were absent in the surface water, probably due to an ontogenetic behavioral shift as a consequence of a change in specific weight during early development. The species composition of fish larvae and juveniles was related to the microhabitats found in the coastal waters. The physico-chemical conditions, along with ontogenetic behavior, played an important role in larval fish distribution in the coastal waters.     

Classification of coastal waters according to the new Italian water legislation and comparison with the European Water Directive

New legislation for the protection of inland surface waters, transitional waters, coastal waters and ground waters has recently been established in Italy. This law presents a new integrated approach, where all water bodies are considered as complex ecosystems to be studied in each of their components. The new concept of environmental quality of the water body, based on the ecological and chemical status, is also introduced. At the same time (i.e. the end of 2000), the European Community approved the European Water Framework Directive based on the same basic environmental concepts and criteria of the new Italian law. This paper analyses the important points and innovations required by the new Italian legislation for monitoring and classification of marine coastal waters. Details of definitions, parameters, analysis and monitoring programs are discussed. A comparison with the European Water Framework Directive is eventually given, underlining the specific characteristics of the Mediterranean sea, which have to be taken into consideration when applying the European Directive to this particular ecoregion.     

Estuarine management strategies and the predictability of ecosystem changes

The Dutch Delta Region (S-W Netherlands) originally consisted of interconnected estuaries, interfacing the rivers Rhine, Meuse and Schelde with the North Sea. The ecosystems were immature, with physical rather than biological control of population dynamics. Main functions were shipping and shellfisheries. An emergent function of the interconnected estuaries was the buffering and upgrading of riverborne substances before they entered the sea. Execution of the Delta Project in the period 1960–1986 resulted in isolation of several water systems disconnected from rivers and sea, and loss of gradients within these systems. Population dynamics were now controlled by chemical and biological rather than physical factors. Vulnerability to external perturbation increased. These changes also affected the buffering capacity, i.e. reduced the utility of the area as stabiliser of the geosystem. Recreational use and appreciation of natural values increased, potentially conflicting with shipping and shellfisheries. Retrospective analysis of the environmental policy and management revealed three consecutive strategies in the Delta Project. 1. Reactive one-issue management, focusing on safety against flooding only. This strategy aimed at complete closure of the estuaries thus transforming them into fresh water lakes. It has destroyed feed-backs and buffering between coastal and inland waters. This strategy has not promoted sustainable development and has increased the vulnerability of the area to future catastrophes. 2. Protective bio-ecological management focused on the preservation of existing values of landscape and environment, and resulted in the maintenance of saline conditions and preservation of marshes by shore protection measures. The drawback of this passive orientation to existing values Ôwhere they are nowÕ is the necessity of continuous intensive care because the natural adaptive ability is not being restored. 3. Constructive geo-ecological management is based on understanding functional properties within and between ecosystems as integrated elements of the landscape structure. This strategy aims at environmental protection, restoration and development of values Ôwhere they must beÕ. Re-establishment of gradients by e.g. re-introducing tidal influence and by restoring salt marshes should contribute to sustainable development.     

An integrated methodology for assessment of estuarine trophic status

This paper describes an integrated methodology for the Assessment of Estuarine Trophic Status (ASSETS), which may be applied comparatively to rank the eutrophication status of estuaries and coastal areas, and to address management options. It includes quantitative and semi-quantitative components, and uses field data, models and expert knowledge to provide Pressure-State-Response (PSR) indicators.A substantial part of the concepts underlying the approach were developed as the United States National Estuarine Eutrophication Assessment (NEEA), which was applied to 138 estuaries in the continental United States. The core methodology relies on three diagnostic tools: a heuristic index of pressure (Overall Human Influence), a symptoms-based evaluation of state (Overall Eutrophic Conditions), and an indicator of management response (Definition of Future Outlook).Recently, the methodology has been extended and refined in its application to European estuaries, and a more quantitative approach to some of the metrics has been implemented. In particular, the assessment of pressure is carried out by means of simple modeling techniques, comparing anthropogenic nutrient loading with natural background concentrations, and the quantitative criteria for classification of system state based on different symptoms have been refined to improve comparability.The present approach has been intercalibrated with the original NEEA work, for five widely different U.S. estuaries (Long Island Sound, Neuse River, Savannah River, Florida Bay and West Mississippi Sound) with good results. ASSETS additionally aims to contribute to the EU Water Framework Directive classification system, as regards a subset of water quality and ecological parameters in transitional and coastal waters.     

Integrated maritime policy for the European Union — consolidating coastal and marine information to support maritime spatial planning

Launch of the Integrated Maritime Policy for the European Union in 2007 served as important factor that stimulates consolidation of coastal and marine information to support policy implementation. Policy’s action plan provides approaches for maritime governance, research and planning relevant to information. In particular, roadmap for maritime spatial planning stimulates development of coastal and marine GIS. Article reviews the current general status of coastal and marine systems and puts them in the context of the policy actions. Main focus is on formation of geospatial information platform for integrated assessment and ecosystem-based management of coastal and marine areas. Recent developments in data, indicator and information systems are summarized in European perspective: better characterization of maritime space and marine ecosystems, development of GMES Marine Core service and related in situ data collection; data harmonisation, interoperability and access, promoted by Shared Environmental Information System principles.     

Geomorphology as an indicator of the biophysical vulnerability of estuaries to coastal and flood hazards in a changing climate

Climate change is increasing the need to characterise the vulnerability of coastal landscapes to coastal and flood hazards that result in erosion and inundation. Indices, such as the Coastal Vulnerability Index (CVI), have emerged as useful tools with which coastal managers can prioritise areas for further detailed assessment of vulnerability, risk, resilience and adaptation options. Approaches, such as the use of an index, efficiently characterise the vulnerability of linear, one-dimensional coastal features such as coastlines; however, they do not capture variability in coastal processes affecting more complex, non-linear features, such as estuaries, or interactive effects of coastal processes between linear (e.g. coastlines) and non-linear (e.g. estuaries) landforms. We present an approach that uses geomorphology to indicate biophysical vulnerability of estuaries to coastal and flood hazards. The approach is applied to the South Coast of NSW; a wave-dominated coastline of approximately 400 km length that contains more than 100 estuaries. We demonstrate the simplicity of the approach and its utility in identifying areas requiring higher resolution assessments. Although this approach does not include socio-economic factors, we demonstrate the capacity to incorporate socio-economic components of vulnerability using regional land use mapping. We infer that the most vulnerable estuaries are characterised by large catchment areas, broad estuarine valleys, mature stages of infill, or entrances oriented towards the prevailing wave direction. The area below 15 m elevation was identified as a robust indicator of the total area of vulnerability within a catchment. This approach can be applied to one-dimensional and more complex two-dimensional landscapes, such as estuaries; integrates varying sea-level rise projections; and incorporates a wider range of hazards that operate in the coastal zone.     

Physical planning in the coastal region of Zeeland, the Netherlands

The Dutch province of Zeeland is situated in the southern part of the Delta region. The geographical location of the province and its history of inundation, land reclamation and dam-building, clearly illustrate the importance that water always has had and still has in The Netherlands. Coastal defence projects are of utmost importance for The Netherlands and the Delta Project is the crown project. The importance of this project does not only regard the protection against the sea; the Delta dams also contribute considerably to the regional infrastructure. They are a important contribution to the abolishment of the former isolation of the region. They control inland navigation and form important boundaries for water management. They separate salt, brackish and fresh water as well as waters with or without tidal-influence and they also influence the ecological systems in and along the waters. Through physical planning, including the coastal policy of today, land and water can be further integrated. This paper discusses the role of the Province in area planning, related to the division of labour between the various public authorities in The Netherlands: state, provinces and municipalities. Coastal and water policy at the provincial level have been largely integrated with relevant other interests. It may be concluded that regional planning and coastal policy are beginning to adopt a new view towards dealing with water.     

Circatidal swimming behavior of brachyuran crab zoea larvae: implications for ebb-tide transport

Larvae of the blue crab Callinectes sapidus and fiddler crab Uca pugilator are exported from estuaries and develop on the continental shelf. Previous studies have shown that the zoea-1 larvae of some crab species use selective tidal-stream transport (STST) to migrate from estuaries to coastal areas. The STST behavior of newly hatched larvae is characterized by upward vertical migration during ebb tide followed by a descent toward the bottom during flood. The objectives of the study were (1) to determine if newly hatched zoeae of U. pugilator and C. sapidus possess endogenous tidal rhythms in vertical migration that could underlie STST, (2) to determine if the rhythms persist in the absence of estuarine chemical cues, and (3) to characterize the photoresponses of zoeae to assess the impact of light on swimming behavior and vertical distribution. Ovigerous crabs with late-stage embryos were collected from June to August 2002 and maintained under constant laboratory conditions. Following hatching, swimming activity of zoeae was monitored in darkness for 72 h. U. pugilator zoeae displayed a circatidal rhythm in swimming with peaks in activity occurring near the expected times of ebb currents in the field. Conversely, C. sapidus zoeae exhibited no clear rhythmic migration patterns. When placed in a light field that simulated the underwater angular light distribution, C. sapidus larvae displayed a weak positive phototaxis at the highest light levels tested, while U. pugilator zoeae were unresponsive. Swimming behaviors and photoresponses of both species were not significantly influenced by the presence of chemical cues associated with offshore or estuarine water. These results are consistent with predictions based on species-specific differences in spawning and the proximity of hatching areas to the mouths of estuaries. U. pugilator larvae are released within estuaries near the adult habitat. Thus, ebb-phased STST behavior by zoeae is adaptive since it enhances export. Selective pressures for a tidal migration in C. sapidus larvae are likely weaker than for U. pugilator since ovigerous females migrate seaward prior to spawning and hatching occurs near inlets and in coastal waters.     

Studies of primary productivity in coastal waters of southern Long Island,New York

Phytoplankton productivity of the tidal estuaries and coastal waters of southern Nassau Country, Long Island, New York, USA was determined monthly at 28 stations during 1966. Diatoms alternated with dinoflagellates in dominating the standing crop in the coastal area. The estuaries were characterized by sustained blooms of green flagellates and dinoflagellates during the spring/summer period, 1966. Chlorophyll a ranged from 1.0 to 27.6 mg/m³ in the estuarine area, and 1.45 to 10.15 mg/m³ in adjacent coastal waters. Rate of phytosynthesis per unit weight chlorophyll a for surface samples in the region under study a veraged from 3.1 to 3.5 mgC/mg chlorophyll a/h. At light saturation, however, the ratio varied according to water temperature and species' composition. Primary productivity decreased seawards, with mean values for 1966 of 0.35, 0.22, and 0.16 gC/m³/d for the estuarine, nearshore and offshore areas, respectively.This study was carried out at the Lamont Geological Observatory of Columbia University Palisades; New York, USA.The study was conducted with financial assistance from Nassau County, New York, and the G. Unger Vetlesen Foundation.