Samantha J Hughes - Profile on Academia.edu (original) (raw)

Papers by Samantha J Hughes

A predictive modelling tool for assessing climate, land use and hydrological change on reservoir physicochemical and biological properties

Area, 2012

ABSTRACT Reservoirs are fundamental for water and energy supply but vulnerable to impacts includi... more ABSTRACT Reservoirs are fundamental for water and energy supply but vulnerable to impacts including climate change. This paper outlines the steps in the development of a model to predict how climate, land use and hydrological change could affect the physiochemical and ecological quality of reservoirs in Portugal's Douro region. Climatic data will be downscaled for subsequent finer spatial scale models to develop scenarios and outputs. Field observations and satellite imagery analysis will create dynamic maps providing data on change in land use and vegetation cover, while Artificial Neural Networks will determine how climate, land use and vegetation cover change may influence catchment hydrology. Data from field surveys of biological indicators, greenhouse gas emissions plus additional research will be applied in the Stochastic Dynamic Methodology, a sequential modelling process based on statistical parameter estimation, developed to predict and model physiochemical and ecological changes in reservoirs. This interdisciplinary approach will provide vital modelling tools for end users essential for water resource management in Portugal and to comply with the EU Water Framework Directive.

Limnetica, 2012

Azorean freshwater invertebrates: Status, threats and biogeographic notes This paper presents an ... more Azorean freshwater invertebrates: Status, threats and biogeographic notes This paper presents an updated catalogue of the freshwater invertebrates of the Azores archipelago and reviews the published records to account for the current taxonomic status and changes in the nomenclature of the listed taxa. The number of freshwater invertebrate species that has been recorded in the Azores has risen sharply throughout the 20th century to 241 species based on field collections and the identification by several generations of local and foreign researchers. The freshwater fauna has been described as the following: (i) being "disharmonic", i.e., lacking taxa commonly found in continental freshwater systems such as the Plecoptera, and (ii) possessing a relatively high degree of endemism in selected groups. As expected, most recorded invertebrates are primarily of Palaearctic origin. However, endemic species make up 11 % of the freshwater invertebrate fauna, which emphasises the unique character of Azorean freshwater habitats, the importance of conservation measures and the need to continue the study of these systems.

FIGURES 7–13 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 7–13. Larval structures of Cloeon peregrinator (except fig. 9: Cloeon dipterum): 7, forel... more FIGURES 7–13. Larval structures of Cloeon peregrinator (except fig. 9: Cloeon dipterum): 7, foreleg. 8, tarsal claw (Cloeon peregrinator). 9, tarsal claw (Cloeon dipterum). 10, distal margin of abdominal tergum IV. 11, lateral margin of abdominal segments VII–IX. 12, gill IV. 13, paraproct.

FIGURES 1–6 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 1–6. Larval structures of Cloeon peregrinator: 1, labrum (left: ventral; right: dorsal). ... more FIGURES 1–6. Larval structures of Cloeon peregrinator: 1, labrum (left: ventral; right: dorsal). 2, hypopharynx. 3, right mandible. 4, left mandible. 5, right maxilla. 6, labium.

FIGURES 25–31 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 25–31. Larval structures of Baetis enigmaticus: 25, foreleg. 26, tarsal claw. 27, distal ... more FIGURES 25–31. Larval structures of Baetis enigmaticus: 25, foreleg. 26, tarsal claw. 27, distal margin of abdominal tergum IV. 28, gill IV. 29, paraproct. 30, median caudal filament. 31, detail of antenna (scape and pedicel).

FIGURES 14–15 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 14–15. Female imago of Cloeon peregrinator: 14, dorsal view. 15, ventral view.

FIGURES 32–33 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 32–33. labial palps of Baetis spp: 32, Baetis atlanticus. 33, Baetis rhodani.

FIGURES 18–24 in Revision of Madeiran mayflies (Insecta, Ephemeroptera)

FIGURES 18–24. Larval structures of Baetis enigmaticus: 18, labrum (left: ventral; right: dorsal)... more FIGURES 18–24. Larval structures of Baetis enigmaticus: 18, labrum (left: ventral; right: dorsal). 19, hypopharynx. 20, right mandible. 21, left mandible. 22, right maxilla. 23, tip of maxillary palp. 24, labium.

Description of a peculiar Rhithrogena nymph from the Iberian Peninsula (Ephemeroptera, Heptagenii... more Description of a peculiar Rhithrogena nymph from the Iberian Peninsula (Ephemeroptera, Heptageniidae) Recent collecting in southern Portugal (Algarve) let to the discovery of an unusual Rhithrogena that possibly belongs to the so-called Rh. sowai group. The nymph of the species is described but not named, and affinities and relationships with other members from the Iberian Peninsula are discussed. Key words: Portugal, Rhithrogena, nymph, Rhithrogena sowai group, description. RESUMEN Descripción de una ninfa peculiar de Rhithrogena para la Península Ibérica (Ephemeroptera, Heptageniidae) Una especie poco frecuente de Rhithrogena, que posiblemente pertenece al llamado grupo Rh. sowai ha sido descubierta en unos muestreos realizados recientemente en el sur de Portugal (Algarve). En este trabajo se describe la ninfa de la especie pero no se le da nombre. Se discuten también las relaciones y afinidades con otros miembros del género de la Península Ibérica.

Limnetica

Combining habitat and biological characterization: ecological validation of the river habitat sur... more Combining habitat and biological characterization: ecological validation of the river habitat survey The River Habitat Survey (RHS) is a widespread technique used to characterize the habitats at the fluvial sector level and to quantify the magnitude of physical disturbances. In this study we tested the ability of this method to discriminate sites along a gradient of perturbation and to analyse its relation with typological and environmental features. At the same time, a biological validation of RHS parameters was carried out by crossing the descriptors with three different aquatic communities (benthic macroinvertebrates, fish, and macrophytes). The Portuguese sector of the Douro basin was the area selected for this purposes. Ordination and classification techniques were used to achieve the objectives mentioned, after a reduction of the variables as a function of their relationships and according to their affinity. The multivariate analysis revealed that the variables associated with the river corridor were more appropriate to differentiate the sampling stations along the gradient of disturbance. However, these variables, together with the ones describing the river conditions (together with the RHS derived indices) were strongly dependent on the typological characteristics. This work shows an adequate strategy for the characterization of the fluvial habitat with biological data to obtain an integrated ecological vision.

Limnetica

Effects of landscape metrics and land-use variables on macroinvertebrate communities and habitat ... more Effects of landscape metrics and land-use variables on macroinvertebrate communities and habitat characteristics The growing number of studies establishing links between stream biota, environmental factors and river classification has contributed to a better understanding of fluvial ecosystem function. Environmental factors influencing river systems are distributed over hierarchically organised spatial scales. We used a nested hierarchical sampling design across four catchments to assess how benthic macroinvertebrate community composition and lower spatial scale habitat descriptors were shaped by landscape and land-use patterns. We found that benthic macroinvertebrate community structure and composition varied significantly from catchment to habitat level. We assessed and identified fractal metrics of landscape descriptors capable of explaining compositional and functional change in the benthic faunal indicators and compared them with the traditional variables describing land use and reach level habitat descriptors within a 1 km radius of each sampling site. We found that fractal landscape metrics were the best predictor variables for benthic macroinvertebrate community composition, function, instream habitat and river corridor characteristics.

Habitat-Oriented Sampling of Macroinvertebrates Affects the Determination of Ecological Status in Temporary Mediterranean River Systems

River Research and Applications, 2014

ABSTRACT Inter-annual and annual variation in precipitation levels in Mediterranean temporary riv... more ABSTRACT Inter-annual and annual variation in precipitation levels in Mediterranean temporary river systems strongly influence riverine flow regimes and as a result habitat’ availability for biological assemblages. Under-sampling of less well-presented microhabitats in such changeable, dynamic systems can result in information loss leading to misclassification of Water Framework Directive (WFD) compliant ecological status, with serious consequences for Programmes of Measures in River Basin Management Plans. This paper compares two benthic macroinvertebrate sampling protocols tested in intermittent Mediterranean streams (n = 40) in the Algarve region of southern Portugal. The officially adopted WFD compliant European assessment system for the ecological quality of rivers using benthic macroinvertebrates, a composite sampling protocol, focuses sampling a greater area of the most representative microhabitats at a given sampling site (proportional habitat sampling). A non-proportional habitat sampling protocol was applied to test the assumption that taxa may have preference for different microhabitats and that this could influence classification of ecological status. Variation was detected in the levels of similarity in the structure and the composition of the benthic macroinvertebrate community within sampling sites and rivers, based on material collected using the two collection methods. Ecological index scores and biotic metrics were higher when the non-proportional oriented sampling protocol was utilized resulting in a ‘good ecological status’ classification at sites that had been classified as ‘Bad’ using the official WFD, Decision tree analysis results indicated that changes in the area of individual microhabitats sampled among protocols was the principal driver behind differences in ecological status derived. The results indicate that more realistic classifications could be achieved in intermittent Mediterranean rivers when considering and sampling less well-represented microhabitat types (non-proportional sampling) rather than distributing sampling effort by the proportion of the dominant habitat present as currently used for the WFD protocol. The application of the non-proportional microhabitat-based approach, which accounts for selective preferences of some benthic macroinvertebrate taxa, would ensure that a greater proportion of a given site community contributes to the assessment.

Boletim do Museu Municipal do Funchal (História Natural) Sup. No. 13

CHIRONOMUS Journal of Chironomidae Research, 2014

Procedia Computer Science, 2015

The Fluvial Ecology Laboratory at the University of Trás-os-Montes and Alto Douro (LEF-CITAB) use... more The Fluvial Ecology Laboratory at the University of Trás-os-Montes and Alto Douro (LEF-CITAB) uses the River Habitat Survey (RHS) methodology a Water Framework Directive accepted method for assessing the character and habitat quality of rivers, which involves the use of a paper questionnaire, GPS and photographic camera for the collection of data in the field, which can be very cumbersome. In order to make this a more efficient and rapid process LEF-CITAB suggested the creation of a mobile application to record field data. This paper outlines the development of the proposed mobile application-Mobile RHS.

Wiley Interdisciplinary Reviews: Water, 2015

The demand for freshwater is projected to increase worldwide over the coming decades, resulting i... more The demand for freshwater is projected to increase worldwide over the coming decades, resulting in severe water stress and threats to riverine biodiversity, ecosystem functioning and services. A major societal challenge is to determine where environmental changes will have the greatest impacts on riverine ecosystem services and where resilience can be incorporated into adaptive resource Page 2 of 21 John Wiley & Sons WIREs Water Resource planners and scientists could better address a growing set of riverine management and risk mitigation issues by (1) using a "Virtual Watersheds" approach based on improved digital river networks and better connections to terrestrial systems; (2) integrating Virtual Watersheds with ecosystem services technology (ARtificial Intelligence for Ecosystem Services: ARIES), and (3) incorporating the role of riverine biotic interactions in shaping ecological responses. This integrative platform can support both interdisciplinary scientific analyses of pressing societal issues and effective dissemination of findings across river research and management communities. It should also provide new integrative tools to identify the best solutions and trade-offs to ensure the conservation of riverine biodiversity and ecosystem services.

Contemporary and future distribution patterns of fluvial vegetation under different climate change scenarios and implications for integrated water resource management

Ecological Research, 2015

Knowledge of plant community structure and how it can confer resistance to climate change effects... more Knowledge of plant community structure and how it can confer resistance to climate change effects is required for the management of fluvial ecosystems. Findings from such studies can be applied in decision making processes to implement measures to maintain, conserve or improve fluvial quality. Floristic and environmental data from 100 sample stations located in three River Basin Districts in northern Portugal were gathered as part of the 2010 Water Framework Directive monitoring program carried out on mainland Portugal. Three habitat types were characterized based on the flow dynamic level: the wetted channel, the bankfull area and the riparian gallery. Hierarchical cluster analysis of environmental data revealed three distinct environmental groups of sites. Floristic data were organized by these environmental groups characterized by altitudinal, temperature and precipitation data variables. The combination of taxonomic diversity and species frequency reflect functional differences for these habitats, here explained by a resistance and resilience approach. More low-frequency species and higher levels of functional diversity occurred at stations with more variable environmental conditions. Predictive modelling of the future distribution of the three environmental groups under two different climate scenarios supported the relevance of low-frequency traits in conferring resistance to climatic change effects.

Freshwater systems in volcanic oceanic islands have very particular characteristics as a result o... more Freshwater systems in volcanic oceanic islands have very particular characteristics as a result of their geological origin and youth, small size, and distinct catchment morphology resulting in freshwater communities that are clearly distinct from continental systems. In accordance with the objectives of the Water Framework Directive the Azorean government launched a monitoring study of streams in 2003; results indicated that more traditional biotic indexes (FBI, BMWP, ASPT and BBI) were unsuitable due to the low level of taxonomic resolution (family level). In order to establish a regional monitoring method for biological assessment of water quality pupal exuviae were sampled in 15 streams in Azores archipelago, situated in three different islands during spring 2008. These were used to test the use of chironomid assemblages for stream classification and water-quality assessment in Azores. Downstream reaches of the streams are organically enriched to different extent, but most of the...

An outline of modelling tool applications in freshwater ecosystem and resource management

""The quality and availability of freshwater are cornerstone determinants for both ecos... more ""The quality and availability of freshwater are cornerstone determinants for both ecosystem and human health worldwide but are deleteriously affected by complex impacts and pressures associated with an increasing world population and developing economies. The deleterious effects of habitat destruction, land use change, chemical pollution, eutrophication and climatic alterations on aquatic ecosystems due to human activities, combined with the urgent need for sustainable management of water resources has led to the development of improved methods for assessing the ecological condition of freshwater systems. Complex numerous but interlinked catchment processes ultimately affect surface water quality and whether mandatory standards set down by cornerstone legislation such as the Water Framework Directive (WFD) will be met. Management strategies must take into account this complexity, including the effect of climate change and develop programmes of actions to maintain or improve ecological and surface water quality, based on results from monitoring programmes. This chapter will outline the importance of mathematical modelling, in particular Stochastic Dynamic Methodology (StDM), in the assessment and management of the ecological integrity of freshwater ecosystems, in particular reservoirs, in Portugal. The methods outlined in this chapter can contribute to the development of new, improved assessment techniques ultimately improving aquatic resource management strategies can be adapted and applied to other regions.""

Fundamental and Applied Limnology / Archiv für Hydrobiologie, 2014

The widespread urbanization of river catchments has resulted in the degradation of many fluvial e... more The widespread urbanization of river catchments has resulted in the degradation of many fluvial ecosystems. We examined the hypothesis that riparian vegetation corridors form effective buffers, mitigating the effects of anthropogenic disturbances in urban river systems. We aimed to identify the principal factors affecting ecological status and biological diversity in the River Corgo (northern Portugal) in order to develop a programme of rehabilitation measures. Data were collected from urban reaches and downstream rural reaches of the River Corgo. We assessed the habitat preferences of two native cyprinid fish species Pseudochondrostoma duriense and Luciobarbus bocagei and also sampled the benthic macroinvertebrate fauna, physicochemical characteristics and hydromorphological support elements following Water Framework Directive compliant protocols. Fish habitat preference curves indicated that the specific habitat preferences of the target native cyprinid fish species were influenced by riparian zone vegetation quality, in addition to micro-habitat characteristics (substrate, current velocity and shelter). Sampling sites located in the urban centre were found to have higher ecological status than sites located in downstream rural and agricultural areas. This may reflect the increased habitat quality and buffering capacity of riparian vegetation, which was better preserved at urban sites. Despite this, non-native fish species were more abundant within urban sites compared to downstream rural sites. The results indicate the significant cumulative effect of anthropogenic influences on downstream sites, such as diffuse pollution from agriculture and loss of riparian cover. Based on the results of this study we recommend that rehabilitation measures should be directed to: a) improve the connectivity of the flowing channel in urban reaches; and b) restore the riparian corridor in the other reaches affected by nutrient input and the spread of invasive fish species.