6,173 research outputs found
“The pond pollinator pantry”: Assessing how pond management influences pollinators in the UK farmland landscape
No full textRecent decades have seen major declines in invertebrate populations across agricultural landscapes, especially amongst pollinating insects. Concurrently, farmland ponds have faced ecological degradation through neglect and ecological succession leading to the widespread development of heavily overgrown and species-poor systems. Recent research has shown ponds to be highly beneficial to pollination, but the mechanisms that connect ponds to pollinating invertebrate species are poorly understood. Similarly, little is known on how the restoration and subsequent management of formerly overgrown farmland ponds impacts upon pollinating insect communities, and whether current pond restoration techniques, involving major woody vegetation removal, mimic what is believed to have occurred at farmland ponds in the past. In this thesis, I examine the drivers of pollinator utilisation of farmland pond systems based on the presence of woody vegetation management, as well as examining historical changes to ponds ecosystems as a means to informing on past pond-plant-pollinator environments and the influence of historic management practices relative to contemporary UK pond restoration approaches. First, I studied the effects of occasional tree and shrub management and pond restoration on flowering plant communities. Influences of pond management on diurnal and nocturnal pollinator richness and abundance were then explored with the general conclusion that such efforts were largely beneficial. Indeed, enhanced flowering plant and pollinator communities also resulted in increased complexity in terms of plant-pollinator interactions. Finally, subfossil analysis of pond sediment cores indicated that current woody vegetation management has historical precedents in the past, with restored pond macrophyte communities having close similarities with subfossil assemblages. With farmland ponds scattered widely across UK farmland landscapes, their conservation represents a massive, untouched resource in the preservation of historical wetland plant and pollinating insect communities
The Ecology and Palaeoecology of Diatom – Duckweed Relationships
No full textThis thesis focuses on the ecology and palaeoecology of diatom-duckweed relationships and utilises a combined experimental, ecological and palaeoecological approach. In particular, the study sought to determine the potential of the epiphytic diatom Lemnicola hungarica to be utilised as a proxy indicator of past dominance of duckweed (Lemna) in small ponds. To this end, contemporary sampling of epiphytic diatom assemblages from a variety of macrophytes (including multiple samples of free-floating plants) were collected from around the world and analysed for diatom epiphytes. In this study, even despite significant environmental gradients, L. hungarica showed a significant association with free-floating plants (including Lemna spp.) as did Sellaphora seminulum. To determine whether this relationship might be used to infer Lemna-dominance in sediment cores, diatom assemblages were analysed in surface sediments from English Lemna and non-Lemna covered ponds and in a core from a pond (Bodham Rail Pit, eastern England) known to have exhibited periods of Lemna-dominance in the past. In both cases, the data suggested that both L. hungarica and S. seminulum were excellent predictors of past Lemna-dominance. Finally, to infer the consequences of Lemna-dominance for the long-term biological structure and ecosystem function of the Bodham Rail Pit, the sedimentary remains of diatoms, plant pigments, and plant and animal macrofossils were enumerated from two sediment cores. These stratigraphic data were compared with the diatom Lemna-indicator metric which indicated three distinct Lemna cycles. Sediment core analyses suggested major compositional, structural and ecological changes brought about by the Lemna cycles, especially in the submerged macrophyte community and in fish-invertebrate relationships. These data reveal that duckweed proliferation, often brought about by eutrophication and terrestrialisation in ponds, can result in dramatic ecological changes due to a strong physical ecosystem engineering effect
Concentrations of Cd, Cu, Mn, Pb, and Zn in Fishes in a Highly Organic Softwater Pond
No full text Concentrations of Cd, Pb, and three essential metals (Cu, Mn, and Zn) in stocked bluegill (Lepomis macrochirus) and eight resident species of fish were studied in an acidic, highly organic pond on the southeastern U.S. coastal plain. Concentrations of Cu, Mn, and Zn in stocked and resident fish were apparently homeostatically controlled in liver tissue, axial musculature, and whole body. Concentrations of all metals studied in axial muscle tissue and whole body of stocked bluegill remained relatively constant after 200 d of residence in the pond. Analysis of concentration factors from pond water to whole stocked bluegill indicated that Pb in this system was less available to fish than in hardwater lakes. In contrast, Cd in the pond was as available to fish as in harder waters. Differences in relative availabilities of Cd and Pb were explained by the tendency of Pb to form complexes with naturally occurring organics. The need for metal-specific analysis of biological availability of metals in highly organic softwater systems is stressed. Key words: trace metal, availability, fish, soft water, concentration factor, organic water </jats:p
Making an impact on UK farmland pond conservation
No full text1.It is of vital importance that aquatic conservation is evidence based, and in the field of farmland pond management and restoration evidence was largely lacking until an article published in Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) in 2012.
2.To examine the influence of farmland pond management on aquatic biodiversity conservation, macrophyte and invertebrate diversity in ponds subject to traditional management involving scrub and occasional sediment removal at different time intervals in the past (0–2, 3–5, 6–10 years since management), were compared with a set of neighbouring, highly terrestrialized ponds that had not been managed for many decades.
3.With the exception of Mollusca, significantly higher species diversity was found for managed ponds compared with the late‐succession unmanaged ponds, with invertebrate gamma diversity significantly lower for the late‐succession ponds, compared with all the managed pond categories.
4.The AQC article was a key component of the Natural England (UK Government's adviser on the natural environment in England) ‘Freshwater and Wetland Conservation Narrative’ and has helped with integrating pond management into recent great crested newt Triturus cristatus mitigation policy as well as bringing it to the fore in past and evolving agri‐environment policy.
5.The AQC article provided the evidence and in turn the confidence for the authors and a number of conservation partners to form a Norfolk Ponds Project. Since 2014, the Project has delivered or facilitated more than 100 pond restorations in Norfolk, eastern England, as well as educating conservation practitioners and farmers on the importance of farmland ponds via various events.
6.With good underpinning science it has been possible to achieve considerable impact in the field of farmland pond conservation. This study shows the importance of setting aside time and support for academic staff to translate applied research outputs into practical impact
Tratamento de esgoto doméstico em lagoas de estabilização com suportes para o desenvolvimento de perifiton - biofilme
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Ambiental.As lagoas de estabilização são sistemas naturais de tratamento de esgotos domésticos que vêm sendo empregadas em todas as regiões do país. Nesses sistemas, o tratamento ocorre mediante fenômenos bioquímicos, biológicos e físico-químicos regulados por uma ampla diversidade de organismos, os quais são responsáveis pela reciclagem da matéria orgânica e dos nutrientes. São sistemas sensíveis às condições climáticas, as quais regulam a atividade das algas e das bactérias envolvidas no processo de tratamento de esgotos. Comumente, os efluentes produzidos em sistemas de lagoas de estabilização apresentam boas condições sanitárias, satisfatória redução do material orgânico carbonáceo afluente, porém, reduzida eficiência de remoção de nutrientes e sólidos em suspensão. Comparativamente aos sistemas lodos ativados que possuem alta concentração de biomassa por unidade de volume, as conversões bioquímicas em lagoas de estabilização ocorrem mais lentamente, necessitando assim maiores tempos de retenção hidráulicos e, conseqüentemente, maiores áreas. A introdução de suportes nas lagoas de estabilização induz a um aumento no contato entre os microrganismos e o efluente, conduzindo a um incremento da atividade da biomassa na lagoa e, conseqüentemente, uma melhora da qualidade do efluente final, inclusive com possibilidade de nitrificação. O objetivo geral desse estudo é avaliar o potencial de utilização de suportes para biofilmes em lagoas de estabilização aplicadas ao tratamento de esgoto doméstico. A base metodológica empregada conduziu a ações diferenciadas em quatro etapas, sendo três destas em escala de laboratório e uma em escala de campo - módulos piloto. Em laboratório buscou-se a identificação do potencial do biofilme/perifiton sob condições ambientais parcialmente controladas, a escolha do material suporte, a relação área suporte/volume do reator, a identificação do incremento de biomassa promovido pelo biofilme e a identificação dos microrganismos via microscopia óptica e análises de biologia molecular. Com as relações obtidas nas diferentes fases de laboratório, partiu-se para o estudo em escala de campo utilizando duas lagoas (área de 15m2, cada), sendo uma com suporte para biofilme (30m2 de suporte), denominada de LB e a outra sem suporte, denominada de lagoa facultativa - LF. Durante os 17 meses de estudo em campo, aplicou-se dois tempos de retenção hidráulico distintos (10 e 20 dias). Os resultados mostraram que o biofilme aderido a suportes de PVC, material selecionado em etapa de laboratório, proporcionou um aumento da biomassa na lagoa correspondente a faixa entre 25% a 57% da biomassa presente nas lagoas sem biofilme. A introdução de suportes de PVC para a adesão de biofilme, numa relação de duas vezes a área superficial da lagoa, contribuiu para uma melhora significativa na qualidade do efluente tratado em termos de DBO5 solúvel quando as lagoas operaram em TRH de 10 dias. A nitrificação não foi detectada em campo. Este processo foi significativo apenas quando as lagoas de laboratório operaram como lagoas terciárias. Na lagoa com biofilme ocorreram menores variações na qualidade do efluente quando maiores cargas foram aplicadas (TRH de 10 dias), sugerindo que uma maior densidade de microrganismos ativos na lagoa (biofilme + plâncton) foi obtida, acelerando o processo de biodegradação dos compostos orgânicos afluentes e tornando o sistema mais estável em caso de variações nas cargas aplicadas. A principal vantagem verificada nas lagoas com biofilmes no tratamento de esgotos foi a expressiva redução na concentração de SS no efluente produzido. Em 50% das etapas experimentais, o efluente da LB apresentou concentrações de SS significativamente inferiores às observadas no efluente da LF. Com maiores áreas de suporte introduzidas nas lagoas (7,5m2/m3 e 5,2m2/m3), menores foram às concentrações de SS no efluente produzido. A introdução de suportes artificiais para adesão de microrganismos constitui uma interessante alternativa aplicada à melhoria do tratamento em sistemas de lagoas de estabilização que se encontram sobrecarregados - sistemas subdimensionados, pois permitem uma manutenção de uma fração maior de microrganismos no sistema. Stabilization ponds are natural systems of domestic wastewater treatment which are being used in all regions of Brazil. In these systems the treatment occurs by biochemical, biological and physico-chemical processes that are regulated by a diversity of organisms which are responsible for the natural organic matter and nutrient recycling. This kind of system is sensitive to climatic conditions that regulate the activity of bacteria and algae involved in the treatment process. Often, the effluents produced in the stabilization pond systems present good sanitary conditions, and a satisfactory reduction in the organic matter content, however, they have limited efficiency regarding the removal of nutrients and suspend solids. In comparison to activated sludge systems that have high biomass concentrations per unit of volume, the biochemical conversions occur more slowly in the ponds, which need longer hydraulic retention times and, consequently, bigger areas. The introduction of supports into the stabilization ponds induces an increase in the contact between the microorganisms and the effluent, leading to an increase in the biomass activity in the pond and the possibility for nitrification and, consequently, a better effluent quality is obtained. The overall aim of this study is to evaluate the potential for the utilization of biofilm supports in stabilization ponds applied to domestic wastewater treatment. The methodology was carried out in four steps, three of them being in laboratory scale and one in field scale - pilot module. In the laboratory we investigated the potential of the biofilm/periphyton under partially controlled environmental conditions, the choice of the support material, the support area/pond volume ratio, the identification of the development of biomass promoted by the biofilm and the identification of the microorganisms by optical microscopy and molecular biology analyses. The ratios obtained in the different phases of laboratory experiments, allowed the study to be carried out in field scale using two ponds (area of 15m2, each). In one of them we placed 30m2 of support and this was called the biofilm pond (LB) and in the other one we did not place anything and this was called the facultative pond (LF). For 17 months of field study, we applied two distinct hydraulic retention times (10 and 20 days). The results showed that the biofilm attached to the PVC plates, the material selected in the laboratory phase, provided an increase in the pond biomass, corresponding to 25% - 57% of the biomass present in the ponds without biofilm. The area of PVC support introduced for the attachment of biofilm, twice the superficial area of the pond, contributed to a significant improvement in the treated effluent quality in terms of soluble BOD5 when the ponds operated with a 10-day HRT. Nitrification was not detected in field scale. This process was significant only when the laboratory ponds operated as tertiary ponds. In the pond with biofilm less variations occurred in the quality of the effluent when higher organic loads were applied (10-day HRT), suggesting that a higher density of active microorganisms in the pond (biofilm + plankton) was obtained, which accelerated the biodegradation process of affluent organic matter and it made the system more stable in the cases where organic loading variations were applied. The main advantage of using the biofilm ponds for wastewater treatment was found to be the significant reduction in SS concentration in the effluent produced. In 50% of the experimental steps, the LB effluent presented SS concentrations significantly lower than those observed in the LF effluent. When larger support areas were introduced in the ponds (7.5m2/m3 and 5.2m2/m3), lower SS concentrations in the final effluent were found. The introduction of supports for the microorganism attachment presented an interesting alternative for the improvement of wastewater stabilization pond treatments when they are overloaded or undersized. The supports permit the maintenance of a greater proportion of microorganisms in the system
Heavy metals retention in Oxidation Pond Systems
No full textSarawak is a key producer of cultured black tiger shrimp (fenaeus monodon) in Malaysia. However, knowledge on the heavy metals in shrimp and culture ponds were lacking in literature. Therefore, in this study, concentrations of selected heavy metals in shrimp pond sludge, pond water, shrimp feed, and shrimp muscles from two farms in different locations were hvestigated. Results indicated that heavy metals concentrations of sludge nearer to the center of the pond were higher than those at the edge of the pond and Zn and Mn concentrations were higher than Cu and Cd. In pond water, concentrations of heavy metals were less than 0.2 mgfL except for Mn in Farm 2 which was much higher. For ShrinlP feed, Zn and Mn concentrations were higher than eu and Cd. The concentration of Cu in feed was different between the two farms. In the shrimp muscles, Zn concentration was the highest followed by Cu. The concentration of heavy metals such as Zn and Cu in the shrimp muscles was not significantly correlated with that in the feed, sludge or water. The concentrations of Zn, Cu and Cd in the shrimp muscle did not exceed the maximum permissible limits of the Malaysian Food Act
Pond ecology and conservation: research priorities and knowledge gaps
No full textPonds are among the most biodiverse and ecologically important freshwater habitats globally and may provide a significant opportunity to mitigate anthropogenic pressures and reverse the decline of aquatic biodiversity. Ponds also provide important contributions to society through the provision of ecosystem services. Despite the ecological and societal importance of ponds, freshwater research, policy, and conservation have historically focused on larger water bodies, with significant gaps remaining in our understanding and conservation of pond ecosystems. In May 2019, pond researchers and practitioners participated in a workshop to tackle several pond ecology, conservation, and management issues. Nine research themes and 30 research questions were identified during and following the workshop to address knowledge gaps around: (1) pond habitat definition; (2) global and long-term data availability; (3) anthropogenic stressors; (4) aquatic–terrestrial interactions; (5) succession and disturbance; (6) freshwater connectivity; (7) pond monitoring and technological advances; (8) socio-economic factors; and (9) conservation, management, and policy. Key areas for the future inclusion of ponds in environmental and conservation policy were also discussed. Addressing gaps in our fundamental understanding of pond ecosystems will facilitate more effective research-led conservation and management of pondscapes, their inclusion in environmental policy, support the sustainability of ecosystem services, and help address many of the global threats driving the decline in freshwater biodiversity.Additional co-authors: James C. White, Robert A. Briers, Kate L. Mathers, Michael J. Jeffries, and Paul J. Woo
Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Bangladesh
No full textThis report is an output of the project ôDetermination of high-potential aquaculture development areas and impact in Africa and Asiaö. This monograph is the case study for Bangladesh. Written in three parts, it describes the historical background, practices, stakeholder profiles, production levels, economic and institutional environment, policy issues, and prospects for aquaculture in the country. First, it documents the history and current status of the aquaculture in the country. Second, it assesses the technologies and approaches that either succeeded or failed to foster aquaculture development and discusses why. Third, it identifies the key reasons for aquaculture adoption.Freshwater aquaculture, Economic analysis, Trade, Ecosystems, Pond culture, Fish consumption, Food security, Policies, Regulations, Legislation, Socioeconomic aspects, Yield, Bangladesh,
Pond amphibian survey with special reference to Great Crested Newts. Manor Farm, Melton Constable, Norfolk
No full textThis data report summarises pond survey information gathered over the course of seven
daytime visits (24/4/04, 25/4/04, 30/4/05, 1/5/05, 2/5/05 1/4/06 and 2/4/06) to Manor
Farm, Melton Constable, North Norfolk. The primary reason for the surveys was to
determine the location and number of ponds occupied by amphibians, specifically Great
Crested Newts (Triturus cristatus). At the same time surveys of aquatic plants were also
undertaken, general habitat notes recorded and Global Positioning System (GPS)
locations ascertained for each pond
A new role for pond management in farmland bird conservation
No full textBiodiversity declines in agricultural landscapes represent a major conservation challenge. In the UK, some agricultural landscapes contain high pond densities, but many farmland ponds have become terrestrialised since the 1960s, with input of organic material resulting in a decrease in the size and depth of ponds that eventually transform into wet woodland habitats. Pond management, including removal of overhanging scrub and sediment, has proven highly effective in enhancing freshwater biodiversity. However, the implications of this management for farmland bird assemblages are unknown. Bird surveys were undertaken at recently managed, open, macrophyte-dominated and at highly terrestrialised, macrophyte-free ponds in the intensively cultivated farmland of North Norfolk, UK. The diversity, abundance and composition of bird assemblages visiting these ponds were compared to determine responses to pond management by tree and mud removal. Avian species richness, abundance and bird-visit frequencies were all higher at open farmland ponds. The observed patterns of bird occurrence were best explained by management-induced reductions in tree shading that resulted in aquatic macrophyte-dominance likely associated with high emergent invertebrate prey abundance. Moreover, we predict that open-canopy ponds offer greater habitat heterogeneity than overgrown ponds, allowing diversified bird use. Overgrown, terrestrialised ponds were preferred by some woodland bird species. Gamma diversity across the entire pondscape exceeded all individual pond alpha diversity measures by an order of magnitude, suggesting distinct variation in the bird assemblages visiting farmland ponds during different successional stages. Pond management that generates a mosaic of pond successional stages, including open-canopy, macrophyte-dominated ponds, could help to address the long-term decline of farmland birds. We strongly advocate increased agro-ecological research in this field, combined with greater emphasis on ponds and pond management options in agri-environment schemes
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