Wetland Loss Research Articles

Future response of global coastal wetlands to sea-level rise.

The response of coastal wetlands to sea-level rise during the twenty-first century remains uncertain. Global-scale projections suggest that between 20 and 90 per cent (for low and high sea-level rise scenarios, respectively) of the present-day coastal wetland area will be lost, which will in turn result in the loss of biodiversity and highly valued ecosystem services1-3. These projections do not necessarily take into account all essential geomorphological4-7 and socio-economic system feedbacks8. Here we present an integrated global modelling approach that considers both the ability of coastal wetlands to build up vertically by sediment accretion, and the accommodation space, namely, the vertical and lateral space available for fine sediments to accumulate and be colonized by wetland vegetation. We use this approach to assess global-scale changes in coastal wetland area in response to global sea-level rise and anthropogenic coastal occupation during the twenty-first century. On the basis of our simulations, we find that, globally, rather than losses, wetland gains of up to 60 per cent of the current area are possible, if more than 37 per cent (our upper estimate for current accommodation space) of coastal wetlands have sufficient accommodation space, and sediment supply remains at present levels. In contrast to previous studies1-3, we project that until 2100, the loss of global coastal wetland area will range between 0 and 30 per cent, assuming no further accommodation space in addition to current levels. Our simulations suggest that the resilience of global wetlands is primarily driven by the availability of accommodation space, which is strongly influenced by the building of anthropogenic infrastructure in the coastal zone and such infrastructure is expected to change over the twenty-first century. Rather than being an inevitable consequence of global sea-level rise, our findings indicate that large-scale loss of coastal wetlands might be avoidable, if sufficient additional accommodation space can be created through careful nature-based adaptation solutions to coastal management.

Can denitrification explain coastal wetland loss: A review of case studies in the Mississippi Delta and New England

There has been considerable discussion over the past several years about the potential negative effects of nutrient loading on coastal wetland stability. In particular, there have been concerns that high nitrate concentrations can fuel denitrification that can lead to soil organic matter loss and wetland deterioration. Here we review these issues for three case studies where there have been elevated levels of dissolved inorganic nitrogen, especially nitrate, coincident with wetland deterioration. These case studies include the Breton Sound estuary that receives diverted Mississippi River water at Caernarvon LA, a freshwater assimilation wetland that receives treated municipal effluent from a wastewater treatment plant at Hammond, LA, and a tidal creek in the Plum Island Sound estuary of northeastern Massachusetts where nitrate was introduced on each flood tide during the growing season for nearly ten years. We review the physical setting, ecology and biogeochemistry of these sites and use stoichiometric calculations to estimate how much soil organic matter decomposition could be accounted for by denitrification. Results of these calculations show that denitrification rates could not have caused the observed marsh deterioration at the two LA marshes. Denitrification may play a significant role in marsh loss at the MA site, however due to the unique hydrology of this site, denitrification rates induced by very high nitrogen loading rates in concert with the hydrology of the site may play a more significant role in marsh deterioration.

Analyzing risk factors for shrinkage and transformation of East Kolkata Wetland, India

The East Kolkata Wetland, called the ‘kidney’ of city Kolkata has now become a significant issue for its gradual loss and modification of anthropogenic activities. A socioeconomic elucidation had been used in this article through the analysis using GIS and field observation. Changes of wetland area have been determined from 1991 to 2017 with Landsat images and accuracy assessment through ground truth verification. It is seen that loss of wetland from 1991 to 2001 was 23.55% where it was 7.34% in 2011 to 2017, mainly due to the result of land transformation for aquaculture activity. Hence, three phases of degradation have been observed in this study, these are: the phase of rapid degradation, the phase of controlled degradation and phase of transforming degraded. At the same time, it’s highlighted the loophole of management actions. A multi-criteria analysis technique with the analytic hierarchy process has been applied to determine the risk factors of wetland degradation and it is seen that expansion of built-up area, encroachment of cropland, the transformation of wetland into fishing ponds are responsible for wetland degradation. In the conclusion, it highlights the approaches of land developers and real estate agents in their wetland hunting process and emergence consequences on the environment as well as conserving approaches for sustainable management.

Assessment of wetland flora and avifauna species diversity in Kafa Zone, Southwestern Ethiopia

Wetland disturbance, degradation, and losses affect wetland-dependent plant and animal species. This study explored the extent of wetland area changes and diversity of plant and bird species in Kafa Zone—one of the most biodiversity-rich area in Ethiopia. Wetland size change and plant and bird species assessment were conducted at two wetlands: Alemgono and Doil following standard scientific procedures. In the past 15 years, 10.2–325.07 ha of wetland areas were converted to other land forms for various uses. The wetlands comprise 36 plant species belonging to 18 families and 56 bird species. Human disturbances and colonization of nonhydrophytes remained as major problems of the wetlands. Alemgono wetland was composed of a large number of plant species with high richness and evenness, whereas Doil wetland contained relatively few species, low richness, and high dominance. Unlike Alemgono, Doli wetland has high bird species richness, evenness, and low dominance. Based on the IUCN (International Union for Conservation of Nature) Red List criteria, 1.82% of birds of the study wetlands were critically endangered, 5.45% were vulnerable, 1.82% were near threatened, 80% were least concerned, and 10.91% were not assessed. This reveals that wetlands of the study area are the habitat for globally threatened bird species and that appropriate conservation measures are needed to save these species.

Unsustainable trade-offs: provisioning ecosystem services in rapidly changing Likangala River catchment in southern Malawi

Provisioning ecosystem services of the Likangala River Catchment in southern Malawi are important for livelihoods of those living there. Remote sensing, participatory mapping and focus group discussions were used to explore the spatio-temporal changes and trade-offs in land-cover change from 1984 to 2013, and how that affects provisioning ecosystem services in the area. Communities derive a number of provisioning ecosystem services from the catchment. Forty-eight species of edible wild animals (including birds), 28 species of edible wild plants and fungi, 22 species of medicinal plants, construction materials, ornamental flowers, firewood, honey, gum, reeds and thatch/weaving grasses were derived from the catchment and used by local communities. These provisioning services are under threat from land-use change within two “hot-spots”, Zomba Mountain and mouth of the river at Lake Chilwa. Zomba Mountain has experienced losses in forests and gains in shrublands, and Lake Chilwa area saw losses of forests, wetlands and shrublands due to increased areas under cultivation. Extrapolation of trends of land cover change in the catchment until 2023 revealed that forests and wetlands will occupy less than 2% of the catchment, while urban areas will grow to over 5% of catchment area. The main driver for land-use change is need for expansion of agricultural land for food production. Participatory mapping and focus group discussions point towards a decline in provisioning services in the catchment and spill-over effects to other catchments. This requires a holistic approach to address the drivers of land-use change for effective management of this ecosystem.

Evaluating the Relationship Among Wetland Vertical Development, Elevation Capital, Sea-Level Rise, and Tidal Marsh Sustainability

Accelerating sea-level rise and human impacts to the coast (e.g., altered sediment supply and hydrology, nutrient loading) influence the accumulation of sediment and organic matter, and thereby impact the ability of coastal tidal wetlands to maintain an elevation consistently within the vegetation growth range. Critical components of marsh sustainability are the marsh elevation within the vegetation growth range (elevation capital) and the rates of marsh surface elevation change and relative sea-level rise. The relationship among these factors and their combined influence on marsh integrity were evaluated by comparing trends in surface elevation change on five salt marsh sites located on three marsh islands in Jamaica Bay, NY, USA. All marsh sites were located in a similar physical setting (i.e., tidal range, sea-level rise rate, sediment supply). The structural integrity of the marshes ranged from densely vegetated (high integrity) to severely deteriorated (low integrity) with elevation capital ranging from high to low, respectively, and included a deteriorating marsh site that was partially restored. Two marshes with high elevation capital maintained their relative position high within the tidal range through a combination of surface sediment deposition and shallow subsurface expansion, and kept pace with local sea-level rise. A marsh with moderate elevation capital showed signs of flooding stress and was deteriorating, but managed to keep pace with local sea-level rise. The deteriorated marsh gained no elevation over the 14-year study and was located too low within the tidal range to support continuous coverage of salt marsh vegetation. Elevation gain in the restored marsh initially lagged behind sea-level rise for 8 years, but the elevation trend recovered and kept pace with sea-level rise for the last 5 years. A conceptual model is presented that describes the relationship among elevation capital, and rates of marsh elevation gain and sea-level rise. Note that a search for factors influencing wetland loss should focus on process changes to marsh vertical development (e.g., sediment supply, vegetation growth) and climate change effects (e.g., sea-level and temperature rise) that can cause elevation gain to lag behind sea-level rise, and these occur prior to the onset of marsh deterioration.

Alternatives for reducing the environmental impact of an ammonia production plant adjacent to a coastal lagoon in the southeastern Gulf of California

There is an increasing demand for N-fertilizers and the manufacture of N-products worldwide. In Mexico, ammonia production is being promoted by the government, but this development is associated with several environmental impacts. This study examines the causes, effects and mitigation alternatives related to the installation and operation of an ammonia production plant adjacent to a coastal lagoon. A multiplicity of causes (and effects) was identified: water suction (elimination of plankton and larvae), effluent discharge (thermal contamination, salinization, and the effects of chlorine), and the conversion of wetlands (loss of habitat and nursery areas, biodiversity, fishery benefits, retention of contaminants, coastal stabilization, carbon storage and aesthetic value). At present, it is estimated that wetlands (9146 ha mangroves + 22,641 ha others) in the Ohuira-Topolobampo lagoon sustain the production of 3000 t live weight of seafood catches per year, implying that the conversion of 126 ha of wetlands could represent for fishermen a catch reduction of 11.9–41.3 t of shellfish per year and a decrease in the annual retention load of up 0.52 kg Cd, 41.0 kg Cu, 0.40 kg Hg, 280 kg Pb, 88.2 t P and 75.6 t N by wetland sediments. To mitigate the environmental effects associated with the installation and operation of the plant, the following is recommended: (i) afforestation of an equivalent area (126 ha), (ii) installation of an exclusion system for fauna to avoid the incidental capture of plankton and larvae, (iii) the use of cooling towers, and (iv) the selection of an appropriate discharge point for the effluent. A list of fauna and flora of the lagoon, as well as environmental services that could be compromised and affected by the operation of the ammonia production plant, is presented. This study is the first to analyze and document such effects and mitigation options related to land conversion and water management, providing useful information for decision makers.

The Second Warning to Humanity – Providing a Context for Wetland Management and Policy

The Second Warning to Humanity provides a clarion call for wetland researchers and practitioners given the loss and degradation of wetlands, the declining availability of fresh water, and the likely consequences of climate change. A coordinated response and approach to policies has the potential to prevent further degradation and support resilient wetlands that can provide a range of ecosystem services, including buffering wetlands from climate impacts, and avoiding major climate amplification from temperature-induced release of additional carbon dioxide and methane while addressing the causes and consequences of global climate change. The Warning to Humanity also provides an opportunity for organisations such as the Society of Wetland Scientists to raise the profile of wetlands and to initiate a discussion on how to respond and change direction from the destructive development trajectory that led to wetland loss and degradation. It also provides a signal for a reappraisal of the effectiveness of the implementation of the Ramsar Convention on Wetlands as an international mechanism for ensuring the sustainability of wetlands.

Water use conflict between wetland and agriculture

To analyze the water use conflict and its driving factors between wetland and agriculture at both regional and local scales, agricultural water consumption and wetland water storage changes in the Sanjiang Plain, the main grain-producing area in Heilongjiang Province of Amur River Basin, were investigated based on statistical data, field survey and GIS calculation. A specific case study in the Qixing River National Nature Reserve (QNNR) wetland-farmland system was completed using a water balance approach. Results showed that the proportion of agricultural water increased from 71.8% to 88.0% while that of ecological water only hovered around approximately 1% in Heilongjiang Province during 2004–2015. Due to wetland loss and degradation, the total surface water storage in the Sanjiang Plain wetlands decreased from 14.46 × 109 t in the 1980s to 4.70 × 109 t in 2010. Agricultural development in successive years, and the dramatic increased requirement for water in paddy fields, intensified the water use conflict between wetlands in the QNNR and surrounding farmlands. Groundwater extraction for irrigation was approximately twice as high as the total infiltration recharge from wetlands and farmlands. It is concluded that the degraded natural water resource endowments are struggle to sustainably support stable grain production as a mainstay of national food safety, which determined the competitive relationship between wetland and agriculture. To mitigate this conflict, adaptive wetland (e.g. water transfer at stagger time, precise water recharge, resourced meltwater) and agricultural techniques (e.g. water-saving irrigation and planting, soil water capacity increment, rainfed agriculture) and five key management solutions were recommended.

A spatial and temporal assessment of wetland loss to development projects: the case of the Kampala–Mukono Corridor wetlands in Uganda

ABSTRACT This article reports an assessment of the spatial and temporal loss of wetlands to development projects (DPs) in the Kampala–Mukono Corridor (KMC). Four sets of satellite images (1974–2013), historical and field data sets were used to assess changes in the spatial extent of wetland land cover types. Through unsupervised classification, wetland cover types and DPs were delineated and future wetland losses to DPs projected through the IDRISI Selva-based Markov Chain model. The KMC wetlands have shrunk by almost a half (47%) since 1974, with DPs accounting for 56% of the total loss. The main drivers of wetland loss are inadequate development planning and the preference for Kampala as an industrial zone. Projections indicate that 61% of the gross KMC wetland loss (42.7%) by 2040 will accrue to more DPs. Wetlands along major transport arteries need conservation by proactive measures.

Quantifying shorebird habitat in managed wetlands by modeling shallow water depth dynamics.

Over 50% of Western Hemisphere shorebird species are in decline due to ongoing habitat loss and degradation. In some regions of high wetland loss, shorebirds are heavily reliant on a core network of remaining human-managed wetlands during migration journeys in the spring and fall. While most refuges have been designed and managed to match the habitat needs of waterfowl, shorebirds typically require much shallower water (<10cm deep). Traditional static habitat modeling approaches at relatively coarse spatial and temporal resolution are insufficient to capture dynamic changes within this narrow water depth range. Our objectives were to (1) develop a method to quantify shallow water habitat distributions in inland non-tidal wetlands, and (2) to assess how water management practices affect the amount of shorebird habitat in Sacramento National Wildlife Refuge Complex. We produced water depth distributions and modeled optimal habitat (<10cm deep) within 23 managed wetlands using high-resolution topography and fixed-point water depth records. We also demonstrated that habitat availability, specifically suitable water depth ranges, can be tracked from satellite imagery and high-resolution topography. We found that wetlands with lower topographic roughness may have a higher potential to provide shorebird habitat and that strategically reducing water levels could increase habitat extent. Over 50% of the wetlands measured provided optimal habitat across <10% of their area at the peak of migration in early April, and most provided a brief duration of shallow water habitat. Reducing water volumes could increase the proportion of optimal habitat by 1-1,678% (mean=294%) compared to actual volumes measured at peak spring migration in 2016. For wetlands with a high habitat potential, beginning wetland drawdown earlier and extending drawdown time could dramatically improve habitat conditions at the peak of shorebird migration. Our approach can be adapted to track dynamic hydrologic changes at broader spatial scales as additional high-resolution topographic (e.g., lidar, drone imagery photogrammetry) and optical remote sensing data (e.g., planet imagery, drone photography) become available.

Four Decades of Estuarine Wetland Changes in the Yellow River Delta Based on Landsat Observations Between 1973 and 2013

Yellow River Delta wetlands are essential for the migration of endangered birds and breeding. The wetlands, however, have been severely damaged during recent decades, partly due to the lack of wetland ecosystem protection by authorities. To have a better historical understanding of the spatio-temporal dynamics of the wetlands, this study aims to map and characterize patterns of the loss and degradation of wetlands in the Yellow River Delta using a time series of remotely sensed images (at nine points in time) based on object-based image analysis and knowledge transfer learning technology. Spatio-temporal analysis was conducted to document the long-term changes taking place in different wetlands over the four decades. The results showed that the Yellow River Delta wetlands have experienced significant changes between 1973 and 2013. The total area of wetlands has been reduced by 683.12 km2 during the overall period and the trend of loss continues. However, the rates and trends of change for the different types of wetlands were not the same. The natural wetlands showed a statistically significant decrease in area during the overall period (36.04 km2·year−1). Meanwhile, the artificial wetlands had the opposite trend and showed a statistically significant increase in area during the past four decades (18.96 km2·year−1). According to the change characteristics revealed by the time series wetland classification maps, the evolution process of the Yellow River Delta wetlands could be divided into three stages: (1) From 1973–1984, basically stable, but with little increase; (2) from 1984–1995, rapid loss; and (3) from 1995–2013, slow loss. The area of the wetlands reached a low point around 1995, and then with a little improvement, the regional wetlands entered a slow loss stage. It is believed that interference by human activities (e.g., urban construction, cropland creation, and oil exploitation) was the main reason for wetland degradation in the Yellow River Delta over the past four decades. Climate change also has long-term impacts on regional wetlands. In addition, due to the special geographical environment, the hydrological and sediment conditions and the location of the Yellow River mouth also have a significant influence on the evolution process of the wetlands.

Remote Sensing and GIS Support to Identify Potential Areas for Wetland Restoration from Cropland: A Case Study in the West Songnen Plain, Northeast China

Wetland restoration is important to responding to climate change and ensuring ecological security. In terms of the serious wetland loss and limited wetland restoration in China, there is a need to investigate approaches to identifying potential areas for wetland restoration from cropland, in order to support making spatial decisions at a regional scale. Here, we provide an example of integrating remote sensing (RS) and geographical information systems (GIS) effectively to identify where and how many croplands could be converted into wetlands in the West Songnen Plain (WSNP). The map of potential areas for wetland restoration from croplands generated in this study is expected to help decision makers to implement wetland restoration in the WSNP. Besides the widely highlighted hydrological, topographical, and landscape features, four indicators, namely, flooded area, time under cultivation, human disturbance, and wetland conservation level, were selected to identify the potential areas for wetland restoration—with different priorities—from croplands. Satellite observation revealed that a total of 2753.3 km2 of wetlands have been cultivated into croplands for grain production from 1990 to 2015 in the WSNP. It is estimated that 8882.1 km2 of croplands are suitable for conversion to wetlands, of which 3706 km2 (29.4%) are with high priority, and 44.5% are from dry farmlands. A total of 3284.7 km2 of paddy fields are identified to be potential areas for wetland restoration, of which 1119.6 km2 are high priority, and another 2165.1 km2 are medium priority.

China's wetlands loss to urban expansion

AbstractHumans benefit from multiple ecosystem services of wetlands, but massive wetland loss has occurred worldwide due to rapid urbanization. To assess the problem, it is necessary to quantify the spatial extent of urbanization‐induced wetland loss. Here, we investigated the amount and pattern of wetland loss in China due to urbanization from 1990 to 2010, based on the China National Land Cover Database (ChinaCover). Our results show that, during these 20 years, China lost 2,883 km2 of wetlands to urban expansion, of which about 2,394 km2 took place in the eastern regions (Northeast China, North China, Southeast China, and South China). The rate of urbanization‐induced wetland loss was 2.8 times higher between 2000 and 2010 (213 km2 year−1) than between 1990 and 2000 (75 km2 yr−1). Of all wetland categories, reservoirs/ponds and marshes suffered the most severe losses. Most of the wetland loss was due to the expansion of urban built‐up areas rather than industrial or transportation lands. Four hotspots of urbanization‐induced wetland loss in China were identified: the Beijing–Tianjin metropolitan region, the Yangtze River Delta, the Jianghan Plain, and the Pearl River Delta. Urbanization and industrialization continue to unfold in China for the next few decades, and the rapid expansion of small‐ and middle‐sized cities and urban traffic networks is expected to encroach on more wetlands. Although great efforts have been made towards wetland conservation in recent years, China must prevent more wetlands from being wiped out by urbanization if the country is to ahieve its sustainable development goals.

Temporal (1970–2016) changes in human pressures and wetland response in the St. Lawrence River (Québec, Canada)

Temporal changes (1970–2016) in St. Lawrence River wetlands were assessed between Cornwall and Québec (≈400 km) to assess wetland response to cumulative anthropogenic pressures in the watershed. Emergent wetlands area and biomass of submerged aquatic vegetation (SAV) were contrasted among five regions subjected to sharply different water level/discharge regime (stabilized, semi-natural, tidal), nutrient concentrations and shoreline use (rural to urbanized). Between 1970 and 2016, over the growing season (April–Sept.), St. Lawrence River mean water level at Sorel dropped by ≈1 m and mean water temperature increased by ≈3 °C. Reductions in phosphorus concentrations (by ≈2-fold) were observed over time both in water and in SAV tissues, in phase with improvements of urban wastewater treatment and P-reduction in upstream Lake Ontario. Nitrate concentrations in water increased and SAV biomass decreased between the 1970s and 2008 in the downstream regions of Lake Saint-Pierre and fluvial corridor subjected to the cumulative impacts from urban centers and intensively farmed watersheds. Over the 1970–2010 period, dropping water levels yielded slightly increasing wetland areas, owing to the downslope colonization of emergent and submerged plants. In urbanized regions, emergent wetlands shifted towards drier assemblages dominated by invasive reed species. Encroachment of wetlands by agriculture accounted for most wetland losses in rural Lake Saint-Pierre, which holds the single largest area (197 km2) of continuous wetland habitat of the entire watershed. Our results highlight the strong response of riverine wetlands to a wide range of human pressures, including dropping water levels, changing nutrient concentrations, rising population and intensifying agriculture.

Mapping Wetlands and Land Cover Change with Landsat Archives: The Added Value of Geomorphologic Data

While classification of remote sensing images has proven useful to quantify wetland losses, wetland mappers have always faced challenges, such as dealing with variable responses of wetlands to meteorological conditions and the obstruction of ground by the canopy in forested wetlands. In this paper, we investigate the added value of using geomorphological data, namely hillslope geometry (through Dikau shapes) and soil drainage classes, as ancillary datasets to map the evolution of wetland cover over the last 35 years. We developed an object-based image analysis method, through a case study in Quebec. Two sets of land cover scenarios (spring and fall) were generated from Landsat archives for 1978, 1985, 1992, 2001, and 2014. Results show that the global accuracy was improved by 19% to 35% when using the geomorphological data, especially soil drainage classes, confirming that their use as ancillary data significantly contributed to the classification process. However, differences were noted between spring and fall scenarios. The wetland cover of the study watershed decreased by 8%–53% between 1978 and 2014 at the expense of an increase in urban areas. Meanwhile, the agricultural land cover decreased (72%–83%) throughout the study period, while forests, water, and bare soil remained stable.

An Interactive Platform for Sustainable Supply Chains

In 2015, the United Nations set up 17 sustainable development goals to transform the world. Sustainable supply chains play a key role in achieving these goals. In this article, the authors propose an interactive platform with communication systems and technologies to empower sustainable development participants actively engaging in managing sustainable supply chains and international soft landings. Specifically, this article illustrates how to develop an interactive “Flying High, Landing Soft” platform of wetland entrepreneurship to address the growing global problem of wetland losses. The interactive platform, grounded in the theory of digital nervous systems and equipped with social interaction technologies, and allows student entrepreneurs to participate in exploring and developing business solutions to maintain a healthy wetland and have positive impact on global sustainability development.

Impacts of coastal reclamation on wetlands: Loss, resilience, and sustainable management

Coastal wetlands are some of the most valuable ecosystems on Earth because they provide many ecological services for coastal security. However, these wetlands are seriously threatened by accelerated climate change and intensive anthropogenic activities. To understand the impacts of land reclamation on landscape change of coastal wetlands and the long-term effects of disturbances of coastal wetlands on their sustainable management, we used time-series Landsat imagery with an object-oriented classification and Digital Shoreline Analysis System to map wetland changes within a reclaimed area in the Pudong District (PD), in Shanghai, China. Our analysis indicated that from 1989 to 2013, 19,793.4 ha of coastal wetlands have been changed to inland wetlands enclosed by a seawall and dike since 1989, thereby cutting off the exchange of sediment and water flux between the wetlands and the coastal ocean. Subsequently, under the increasing threats of anthropogenic activities, the wetland ecosystem collapsed sharply, in a transformation chain of inland wetland (fresh swamp), artificial wetland (agriculture and aquaculture wetland), and non-wetland (urban land). Under this explosive utilization following coastal reclamation, only 8.9% of natural wetlands remain in the reclaimed area, which has experienced an average annual wetland loss rate of 3.8% over the past 24 years. More than 80% of the wetlands have been developed for agricultural, industrial, and urban land uses, leading to an enormous loss of associated ecological services—benefits arising from the ecological functions provided by wetland ecosystems, thereby undermining the coastal protection these wetlands provided. Nevertheless, considerable regeneration of wetlands occurred because of their inherent resilience. This paper addresses the importance of maintaining a balance between economic growth and coastal ecological protection for sustainable management. It proposes a strategy for how ecosystem-based land planning and ecological engineering should be applied to ensure the effective and sustainable management of living shorelines so that the benefits of healthy ecological functions accrue to coastal ecosystems.

Assisting Nature: Ducks, “Ding” and DU by Arnold van der Valk

J ay “Ding” Darling (1876-1962) was a newspaper editorial cartoonist and duck hunter. Because of his proconservation cartoons, he had become one America’s most prominent conservationists by the early 1930s. Joseph P. Knapp (1864-1951) was a prominent businessman, philanthropist, conservationist, and duck hunter who, like Darling, had become concerned about the decline of waterfowl populations. Both worked to reverse this duck decline. Darling was appointed chief of the Bureau of Biological Survey in 1934 by President Franklin Roosevelt. During his short tenure as its chief (1934-1935), he focused the Bureau’s mission more on wildlife conservation and he oversaw the expansion of the national wildlife refuge system. In 1930, Knapp founded the More Game Birds in America Foundation. This Foundation through its waterfowl surveys documented that western Canada was the major breeding ground of ducks in North America. This resulted in the Foundation establishing Ducks Unlimited, Inc. in the US and Ducks Unlimited (Canada) in 1937. DU, Inc. would raise money, and DU (Canada) would spend this money in western Canada on wetland conservation and restoration projects. Both men helped to slow down the loss of wetlands by stressing the need for the public and private sectors to conserve and restore them as waterfowl habitat. They also shaped future wetland science by creating opportunities for the employment of wetland scientists.

Application of Geospatial Technology for Wetlands’ Mapping and Change-Detection: A Case Study in Selected Areas of South Eastern Coast in Ampara District, Sri Lanka

In global context, the anthropogenic pressure increases the loss of wetland and its resources. Wetlands and estuaries are highly productive and act as critical habitats for a variety of plants, fish, shellfish, and other wildlife (Klemas, 2011). The detection and evaluation of the wetland with modern technology is an important phenomenon to conserve the wetland area and its ecosystem. Remote sensing (RS) has a long history of successful applications within the field of wetland delineation, using a multitude of satellite platforms and sensors (Allan, 2016). This paper is an attempt to object-based approach to derive the change detection inventory information of wetland for selected administrative areas of South Eastern coast in Ampara District within the period of 1991 to 2017 using Toposheets and Google Earth imagery. Further, it also explores the human activities which pressure on wetland including agricultural practices (land encroachment), new settlements, solid waste dumping, land cover changes and etc. Google Earth imagery of 1991 and 2017 were collected and subjected to the GIS analysis to find the result of this study. According to the results, agricultural and built-up area has increased in 1991 by (9.4 per cent), 2017 (16.4 per cent) and 1991 (0.1 per cent), 2017 (2.1 per cent) respectively whereas there has been a decrease in the forest and wetland areas in the years of 1991 (80.3 per cent), 2017 (72.7 per cent) and 1991 (3.5 per cent), 2017 (2.9 per cent) respectively.