Consulta: subjectFacets:"Food web"
Registros recuperados: 46
Data/hora: 04/06/2024 06:38:10

Adaptive Harvesting in a Multiple-Species Coral-Reef Food Web
Provedor de dados: 7
Autores: Kramer, Daniel B; Michigan State University; dbk@msu.edu.
The utility of traditional bio-economic harvest models suffers from their dependence on two commonly used approaches. First, optimization is often assumed for harvester behavior despite system complexity and the often neglected costs associated with information gathering and deliberation. Second, ecosystem interactions are infrequently modeled despite a growing awareness that these interactions are important. This paper develops a simulation model to examine the consequences of harvesting at two trophic levels in a coral-reef food web. The model assumes adaptive rather than optimizing behavior among fishermen.  The consequences of changing economic, biological, and social parameters are examined using resilience as an evaluative framework. Three general...
Tipo: Peer-Reviewed Reports
Palavras-chave: Fisheries; Resource economics; Coral reefs; Resilience; Adaptive behavior; Food web; Simulation.
Ano: 2008

Особенности формирования хроматофорного комплекса камбалы калкан Psetta maxima var. maeotica в онтогенезе в зависимости от пищевой цепи.
Provedor de dados: 13
Autores: Ханайченко, А. Н.; Битюкова, Ю. Е.
Сравнение влияния пищевой цепи на развитие пигментации (хроматофорного комплекса) у камбалы калкан Psetta maxima var. maeotica проводили от начала экзогенного питания до начала метаморфоза (3 - 18 сут) и от начала до последней стадии метаморфоза (18 – 60 сут). Группы калкана (в двух повторностях, из однородных партий икры) содержали в разных пищевых цепях: либо в типично морской, состоящей из культивируемых каланоидных копепод, Acartia tonsa (группа MZ), либо в искусственной, состоящей из солоноватоводных коловраток Brachionus plicatilis и метанауплиев Artemia  franciscana (группа BZ). Для аппроксимации  жирнокислотного состава применяли единую схему насыщения, в результате которой у всех кормовых организмов были близкие значения содержания и соотношения...
Tipo: Journal Contribution
Palavras-chave: Калкан; Пищевая цепь; Пигментация; Меланофор; Липофор; Гуанофор; Дифференциация; Black Sea turbot; Food web; Pigmentation; Melanophore; Lipophore; Guanophore; Differentiation; Харчовий ланцюг; Пігментація; Меланофор; Ліпофор; Гуанофор; Діфференціація.
Ano: 2007
URL: http://repository.ibss.org.ua/dspace/handle/99011/849

Effet d’une espèce ingénieur sur la diversité et le fonctionnement des communautés benthiques : l’habitat récifal à Sabellaria alveolata
Provedor de dados: 5
Autores: Jones, Auriane.
Coastal zones worldwide are home to a large diversity of ecosystem engineers that perform key functions such as the recycling of organic matter and nutrients. The habitats resulting from the biological activity of these species are exposed to numerous disturbances such as over harvesting and trampling or via coastal modification. In this context, it is becoming key to understand the functioning of these engineered habitats and how they are affected by increasing disturbances. During my PhD, I used the reef habitat built by the gregarious tubiculous polychaete Sabellaria alveolata as a study case. First, the environmental and biotic changes associated with the establishment of a S. alveolata reef and its increasing disturbance were assessed, focusing on...
Tipo: Text
Palavras-chave: Ingénieur de l’écosystème; Habitat récifal; Macrofaune benthique; Diversité fonctionnelle et isotopique; Production primaire benthique; Réseau trophique; Flux biogéochimiques; Traits biologiques; Ecosystem engineer; Reef habitat; Benthic macrofauna; Functional and isotopic diversity; Facilitation; Benthic primary production; Food web; Biogeochemical fluxes; Isoscape; Biological traits.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00498/60960/64363.pdf

Short-scale temporal variability of physical, biological and biogeochemical processes in the NW Mediterranean Sea: an introduction
Provedor de dados: 5
Autores: Andersen, V.; Goutx, M.; Prieur, L.; Dolan, J. R.
In the framework of the PROOF-PECHE project (http://www.obs-vlfr.fr/proof/vt/op/ec/peche/pec.htm) a multi-disciplinary team performed experiments and collected samples during the DYNAPROC2 cruise aboard the RV Thalassa from September to October in 2004. The cruise provided data on the functioning of the pelagic food web by sampling over a month long period in the NW Mediterranean Sea at a fixed station subject to weak horizontal advection currents during a period of hydrological stability. This paper describes the background of the cruise and provides an overview of the results derived from the campaign which constitute the special section. The major objective of the cruise was to assess the relative importance and variability of the pathways of carbon in...
Tipo: Text
Palavras-chave: Spring bloom; Zooplankton community; Vertical distribution; Surface layer; Wind events; Bacterial communities; Food web; Transition; Oligotrophy; Abundance.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00092/20315/17954.pdf

The Channel habitat atlas for marine resource management (CHARM): an aid for planning and decision-making in an area under strong anthropogenic pressure
Provedor de dados: 5
Autores: Martin, C. S.; Carpentier, Andre; Vaz, Sandrine; Coppin, Franck; Curet, L.; Dauvin, J. -c.; Delavenne, Juliette; Dewarumez, J. -m.; Dupuis, L.; Engelhard, G.; Ernande, Bruno; Foveau, A.; Garcia, C.; Gardel, Laure; Harrop, S.; Just, R.; Koubbi, P.; Lauria, Valentina; Meaden, G. J.; Morin, Jocelyne; Ota, Y.; Rostiaux, Emilie; Smith, R.; Spilmont, N.; Verin, Yves; Villanueva, Ching-maria; Warembourg, Caroline.
The eastern English Channel, the narrow channel of water separating northern France and southeast England is an area of intense human use of the array of resources concentrated into its relative small area. The vulnerability of living resources and their habitats brought together French and British maritime experts within a common project (called CHARM): to create an atlas of marine resource habitats in the eastern English Channel so as to provide planners and decision-makers with the necessary information to help managing the use of its living and non-living resources. This multidisciplinary and richly illustrated atlas provides abundant information on the legal framework and physical environment; benthic invertebrates, fish and their habitats; fishing...
Tipo: Text
Palavras-chave: Eastern English Channel; Dover Strait; Benthos; Fish; Habitat; Ecosystem; Marine spatial planning; Fisheries; Legislation; Trophic network; Food web; GIS; Geographic Information System.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11169/7523.pdf

Stable isotope analysis position of intertidal of food source and trophic nematodes and copepods
Provedor de dados: 5
Autores: Rzeznik Orignac, J; Boucher, G; Fichet, Denis; Richard, P.
Four dominant nematode species and various copepods from an intertidal mudflat in Marennes-Oleron Bay were analyzed for delta C-13 and delta N-15 ratios together with their potential food source, the microphytobenthos. It was shown that microphytobenthic C is passed to nematodes either by grazing or predation on herbivorous meiofauna by other nematodes. Diatoms of different sizes exhibited different C-13 content, which can be reflected in herbivorous meiofauna, such as the nematodes Daptonema oxycerca and Metachromadora remanei and the bulk of copepods, indicating they can select different sizes of diatoms. Results confirm the need to analyze meiofauna feeding habits at the species or genera level since the delta N-15 and delta C-13 signatures differed...
Tipo: Text
Palavras-chave: Stable isotopes; Marennes Oleron; Mudflat; Food web; Benthic diatoms; Microphytobenthos; Meiofauna; Copepods; Nematodes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4292.pdf

Trophic relationships in a deep Mediterranean cold-water coral bank (Santa Maria di Leuca, Ionian Sea)
Provedor de dados: 5
Autores: Carlier, A.; Le Guilloux, E.; Olu, Karine; Sarrazin, Jozee; Mastrototaro, F.; Taviani, M.; Clavier, J.
Cold-water corals (CWC) are frequently reported from deep sites with locally accelerated currents that enhance seabed food particle supply. Moreover, zooplankton likely account for ecologically important prey items, but their contribution to CWC diet remains unquantified. We investigated the benthic food web structure of the recently discovered Santa Maria di Leuca (SML) CWC province (300 to 1100 m depth) located in the oligotrophic northern Ionian Sea. We analyzed stable isotopes (delta C-13 and delta N-15) of the main consumers (including ubiquitous CWC species) exhibiting different feeding strategies, zooplankton, suspended particulate organic matter (POM) and sedimented organic matter (SOM). Zooplankton and POM were collected 3 m above the coral...
Tipo: Text
Palavras-chave: Particulate organic matter; Zooplankton; Stable isotopes; Food web; Mediterranean Sea; Benthic community; Cold water corals.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-7450.pdf

Understanding patterns and processes in models of trophic cascades
Provedor de dados: 5
Autores: Heath, Michael R.; Speirs, Douglas C.; Steele, John H.
Climate fluctuations and human exploitation are causing global changes in nutrient enrichment of terrestrial and aquatic ecosystems and declining abundances of apex predators. The resulting trophic cascades have had profound effects on food webs, leading to significant economic and societal consequences. However, the strength of cascades-that is the extent to which a disturbance is diminished as it propagates through a food web-varies widely between ecosystems, and there is no formal theory as to why this should be so. Some food chain models reproduce cascade effects seen in nature, but to what extent is this dependent on their formulation? We show that inclusion of processes represented mathematically as density-dependent regulation of either consumer...
Tipo: Text
Palavras-chave: Bottom-up; Density dependence; Food chain; Food web; Harvesting; Model; Predator-prey; Simulation; Top-down.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00171/28249/26505.pdf

Influences of geothermal sulfur bacteria on a tropical coastal food web
Provedor de dados: 5
Autores: Pascal, Pierre-yves; Dubois, Stanislas; Goffette, Anais; Lepoint, Gilles.
The activity of the geothermal plant at Bouillante in Guadeloupe (French West Indies) releases thioautotrophic bacteria into the coastal environment. Fish counts reveal that fish abundance increases with higher availability of this bacterial resource. In order to evaluate the trophic role of these bacteria, isotopic compositions (C, N, S) of potential consumers were evaluated on transects at increasing distance from the source of bacteria. The 3 mobile fish species examined (Abudefduf saxatilis, Acanthurus bahianus, and Stegastes partitus) ingested and assimilated chemosynthetic bacteria. Similarly, the isotopic composition of the mobile sea urchin Diadema antillarum was different close to the discharge channel, suggesting a diet mainly composed of sulfur...
Tipo: Text
Palavras-chave: Shallow vent; Food web; Sulfur bacteria; Stable isotope.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00404/51511/52256.pdf

Couplage de modèles trophiques et effets combinés de la pêche et du climat
Provedor de dados: 5
Autores: Travers, Morgane.
Overfishing and climate change are now recognized to have important effects on marine ecosystem functioning but uncertainties remains about their combined effects. Using a modelling approach this thesis aims at assessing how the top-down effects of fishing and the bottom-up effects of climate combine themselves within the food web. A preliminary review highlighted the lack of end-to-end model applicable as it stands to our study case - the southern Benguela - and suitable to study the combined effects of fishing and climate. Coupling the plankton model ROMS-N2P2Z2D2 and the fish model OSMOSE appeared as an innovative method allowing to develop an appropriate tool meeting our objectives. The importance of two-way coupling via the predation process is first...
Tipo: Text
Palavras-chave: Modèle end-to-end; Couplage de modèle; Réseau trophique; Sud- Benguela; Effets combinés; Changement climatique; Surexploitation; End-to-end model; Model coupling; Food web; Southern Benguela; Combined effects; Climate change; Overfishing.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00003/11445/7993.pdf

Typologie biosédimentaire de la baie de Saint-Brieuc (Manche ouest), et estimation de la biomasse des catégories trophiques macrozoobenthiques.
Provedor de dados: 5
Autores: Gros, Philippe; Hamon, Dominique.
The aim of this report is to provide biomass estimates (AFDW, g.m-2 ) of the four main components of the benthic food web in the southern part of the Bay of St-Brieuc: suspension-feeders, deposit-feeders, herbivores and carnivores. Patterns in the environmental data (i.e., sedimentary characters) are first analysed, and then related to the spatial distribution of communities ; both approaches use classical ordination techniques (PCA, correspondence analysis). A second typology, based on a review of published litterature concerning coastal macrozoobenthos feeding, ascribes each taxonomic unit to a trophic group. Finally, quantitative results are thus given per biota ; suspension-feeders appear to dominate (in terms of biomass) most of fine-sand habitats of...
Tipo: Text
Palavras-chave: Zoobenthos; Réseau trophique; Analyses multivariables; Manche ouest; Zoobenthos; Food web; Multivariate analysis; Western Channel.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/00107/21794/19371.pdf

Caractérisation et modélisation des processus de bioaccumulation des PCB chez le merlu (Merluccius merluccius) du golfe du Lion
Provedor de dados: 5
Autores: Bodiguel, Xavier.
Understanding bioaccumulation mechanisms of persistent organic pollutants (POPs) is a major issue for environmental risk assessment. In this work, polychlorinated biphenyls (PCBs), a model contaminant family, has been studied in the European hake (Merluccius merluccius), a high trophic level species from the Gulf of Lions. High concentrations of PCBs were measured in hake from this area compared to those encountered in the population of the Bay of Biscay. PCB biomagnification was highlighted along its food web from marine phytoplankton, suggesting a strong influence of diet on contamination levels. The role of other biological processes was also apprehended in order to understand the high variability of observed levels. Thus, growth, sex, and also the...
Tipo: Text
Palavras-chave: DEB theory; Bioenergetic model; Gulf of Lions; Biomagnification; Food web; Hake; Bioaccumulation; Polychlorinated biphenyls; Organic contaminants; Théorie DEB; Modèle bioenergétique; Golfe du Lion; Bioamplification; Réseau trophique; Merlu; Bioaccumulation; Polychlorobiphényles; Contaminants organiques.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/these-6490.pdf

Seagrass organic matter transfer in Posidonia oceanica macrophytodetritus accumulations
Provedor de dados: 5
Autores: Remy, François; Mascart, Thibaut; De Troch, Marleen; Michel, Loic; Lepoint, Gilles.
Seagrass ecosystems are net autotrophic systems which contribute to organic carbon burial in marine sediment. Dead seagrass leaves are often exported outside the seagrass beds and may form accumulations (exported macrophytodetritus accumulations, hereafter EMAs) from littoral zones to deepest canyons. Understanding how seagrass organic matter is channeled in its associated trophic web is necessary to assess the role of the seagrass ecosystem as blue carbon service providers. We used gut content and stable isotope analyses to delineate the Posidonia oceanica EMA food web structure and to determine the importance of detrital material in the diets of macrofauna. Evidence from gut contents and stable isotopes showed that this food web is fuelled mainly by two...
Tipo: Text
Palavras-chave: Stable isotopes; Detrital pathway; Mixing models; Trophic level; Invertebrates; Mediterranean Sea; Food web.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00448/55969/57464.pdf

Contamination of some aquatic species with the organochlorine pesticide chlordecone in Martinique
Provedor de dados: 5
Autores: Coat, Sophie; Bocquene, Gilles; Godard, Eric.
Martinique is a French overseas department whose economy relies heavily on agriculture. Organochlorine pesticides, mainly chlordecone, were used for banana cultivation to eradicate banana weevil over a period of 40 years. Chlordecone is chemically stable,and has a strong affinity for fatty tissues. It is therefore able to bioaccumulate in animals and thereby represent a threat to ecosystems and man. Soils from banana plantations in Martinique are heavily contaminated with chlordecone. Possible transfer of these molecules from agricultural watersheds to the aquatic environment and the organisms that live in it is feared. The hypothesis that ecosystems of Martinique might be highly contaminated with this organochlorine pesticide was investigated. Chlordecone...
Tipo: Text
Palavras-chave: W Atlantic; Caribbean Islands; Food web; Aquatic organisms; Chlordecone; Contamination; Pesticides.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1662.pdf

Network analysis and inter-ecosystem comparison of two intertidal mudflat food webs (Brouage Mudflat and Aiguillon Cove, SW France)
Provedor de dados: 5
Autores: Leguerrier, D; Degre, Delphine; Niquil, N.
Network analysis was used to analyse steady-state models of the food webs of two intertidat mudflat ecosystems: Aiguillon Cove and Brouage Mudflat, on the South-Western Atlantic Coast of France. The aim was to highlight emergent properties of food-web functioning in these two ecosystems and to compare these properties with other coastal ecosystems. Both ecosystems imported detritus in parallel to a high benthic primary production. They were characterised by a high diversity of resources. Both also exported living material, leading to a high quality production, quantified as export of Exergy. This export was mainly composed of cultivated bivalves during the cold season for Brouage Mudflat, and of the migration of grazing fish in Aiguillon Cove during the...
Tipo: Text
Palavras-chave: Atlantic coast; Intertidal mudflat; Network analysis; Inverse analysis; Ecosystem comparison; Food web.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-3696.pdf

Diverse molecular signatures for ribosomally 'active' Perkinsea in marine sediments
Provedor de dados: 5
Autores: Chambouvet, Aurelie; Berney, Cedric; Romac, Sarah; Audic, Stephane; Maguire, Finlay; De Vargas, Colomban; Richards, Thomas A.
Background: Perkinsea are a parasitic lineage within the eukaryotic superphylum Alveolata. Recent studies making use of environmental small sub-unit ribosomal RNA gene (SSU rDNA) sequencing methodologies have detected a significant diversity and abundance of Perkinsea-like phylotypes in freshwater environments. In contrast only a few Perkinsea environmental sequences have been retrieved from marine samples and only two groups of Perkinsea have been cultured and morphologically described and these are parasites of marine molluscs or marine protists. These two marine groups form separate and distantly related phylogenetic clusters, composed of closely related lineages on SSU rDNA trees. Here, we test the hypothesis that Perkinsea are a hitherto under-sampled...
Tipo: Text
Palavras-chave: 454 pyrosequencing; Perkinsus; Parvilucifera; Food web; Protist; Parasite.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00374/48496/48830.pdf

Investigating trophic-level variability in Celtic Sea fish predators
Provedor de dados: 5
Autores: Chassot, E; Rouyer, Tristan; Trenkel, Verena; Gascuel, D.
The trophic level mean and variance, and the degree of omnivory for five Celtic Sea fish predators were estimated using a database of stomach content records characterized by a high level of taxonomic resolution. The predators occupied a high position in the food web, i.e. 4.75 for Atlantic cod Gadus morhua, 444 for haddock Melanogrammus aeglefinus, 4.88 for European hake Merluccius merluccius, 5.00 for megrim Lepidorhombus whiffiagonis and 5.27 for whiting Merlangius merlangus. The level of taxonomic resolution of the prey did not greatly affect mean T-L predator values; an effect on variance was evident, low resolution masking intra-population variability in T-L. Generalized additive models (GAM) were used to explain the variability of predator T-L...
Tipo: Text
Palavras-chave: Trophic level; Predation; Omnivory; Indicator; GAM; Food web.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4699.pdf

Trophic structure in the Gulf of Lions marine ecosystem (north-western Mediterranean Sea) and fishing impacts
Provedor de dados: 5
Autores: Banaru, Daniela; Mellon, Capucine; Roos, David; Bigot, Jean-louis; Souplet, Arnauld; Jadaud, Angelique; Beaubrun, P.; Fromentin, Jean-marc.
The Gulf of Lions ecosystemwas described using the Ecopath mass-balancemodel to characterise its structure and functioning and to examine the effects of themultispecific fisheries operating in this area. The model is composed of 40 compartments, including 1 group of seabirds, 2 groups of etaceans, 18 groups of fish, 12 groups of invertebrates, 5 groups of primary producers, detritus and discards. Input datawere based on several recurrent scientific surveys, two alternative datasets for fishing data, stock assessment outputs, stomach content analyses and published information. Results showed that the functional groups were organised into five trophic levels with the highest one represented by dolphins, anglerfish, Atlantic bluefin tuna, European hake and...
Tipo: Text
Palavras-chave: Gulf of Lions; Ecopath with Ecosim; Food web; Fishing impacts.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00116/22758/20614.pdf

There's no harm in having too much: A comprehensive toolbox of methods in trophic ecology
Provedor de dados: 5
Autores: Majdi, Nabil; Hette-tronquart, Nicolas; Auclair, Etienne; Bec, Alexandre; Chouvelon, Tiphaine; Cognie, Bruno; Danger, Michael; Decottignies, Priscilla; Dessier, Aurélie; Desvilettes, Christian; Dubois, Stanislas; Dupuy, Christine; Fritsch, Clémentine; Gaucherel, Cédric; Hedde, Mickaël; Jabot, Franck; Lefebvre, Sebastien; Marzloff, Martin; Pey, Benjamin; Peyrard, Nathalie; Powolny, Thibaut; Sabbadin, Régis; Thébault, Elisa; Perga, Marie-elodie.
Trophic ecology is the study of feeding interactions and food acquisition by organisms. It includes the causes and consequences of those behaviours at all levels of biological organisation. As a field of research, it crosses many disciplinary boundaries and provides knowledge that is pertinent to many other areas of ecology. Here we list and categorise the methods available to trophic ecologists whose toolbox has broadened considerably in recent years. They encompass empirical and numerical approaches with focus ranging from molecules to ecosystems. We further examine the relationship of each method to features such as the scale of observation (from microbes to largest organisms) and organisational level (from individuals to ecosystems) as well as the...
Tipo: Text
Palavras-chave: Food web; Feeding interactions; Flux of energy; Computer simulations; Trophic models.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00487/59834/65986.pdf

Biomass changes and trophic amplification of plankton in a warmer ocean
Provedor de dados: 5
Autores: Chust, Guillem; Allen, J. Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason; Tsiaras, Kostas; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle; Daewel, Ute; Wakelin, Sarah L.; Machu, Eric; Pushpadas, Dhanya; Butenschon, Momme; Artioli, Yuri; Petihakis, Georges; Smith, Chris; Garcon, Veronique; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A.; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier.
Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis,...
Tipo: Text
Palavras-chave: Ecosystem model; Food web; Plankton; Primary production; Sea warming; Trophic amplification.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00188/29966/28481.pdf

Spatial analysis of the trophic interactions between two juvenile fish species and their preys along a coastal-estuarine gradient
Provedor de dados: 5
Autores: Kopp, Dorothee; Le Bris, Herve; Grimaud, Lucille; Nerot, Caroline; Brind'Amour, Anik.
Coastal and estuarine systems provide nursery grounds for many marine fish species. Their productivity has been correlated with terrigeneous inputs entering the coastal-estuarine benthic food web, thereby favouring the establishment of fish juveniles. Studies in these ecosystems often describe the nursery as a single large habitat without verifying nor considering the presence of contiguous habitats. Our study aimed at identifying different habitats based on macrozoobenthic communities and morpho-sedimentary characteristics and assessing the trophic interactions between fish juveniles and their benthic preys within these habitats. It included 43 sampling sites covering 5 habitats in which we described taxonomically and quantitatively the invertebrates and...
Tipo: Text
Palavras-chave: Stable isotopes; Gut content; Food web; Nursery ground; Solea solea; Trisopterus luscus.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00151/26226/24327.pdf

Trophic flow structure of a neotropical estuary in northeastern Brazil and the comparison of ecosystem model indicators of estuaries
Provedor de dados: 5
Autores: Lira, Alex; Angelini, Ronaldo; Le Loc'H, Francois; Menard, Frederic; Lacerda, Carlos; Fredou, Thierry; Fredou, Flavia Lucena.
We developed an Ecopath model in the Estuary of Sirinhaém River (SIR), a small-sized system surrounded by mangroves, subject to high impact, mainly by sugar cane industry and other farming industries in order to describe the food web structure and trophic interactions. In addition, we compared our findings with those of 20 available Ecopath estuarine models for tropical, subtropical and temperate regions, aiming to synthesize the knowledge on trophic dynamics and provide a comprehensive analysis of the structures and functioning of estuaries. Our model consisted of 25 compartments and its indicators were within the expected range for estuarine areas around the world. The average trophic transfer efficiency for the entire system was 11.8%, similar to the...
Tipo: Text
Palavras-chave: Tropical estuary; Ecopath; Food web; Global comparison of ecological indicators.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00428/53929/55061.pdf

Emergence of negative trophic level-size relationships from a size-based, individual-based multispecies fish model
Provedor de dados: 5
Autores: Travers-trolet, Morgane; Coppin, Franck; Cresson, Pierre; Cugier, Philippe; Oliveros-ramos, Ricardo; Verley, Philippe.
Modeling the mechanisms underlying trophic interactions between individuals allows the food web structure to emerge from local interactions, which constitutes a prerequisite for assessing how marine ecosystems respond to various anthropogenic pressures. Using a multispecies spatially explicit individual-based model, the emergence of trophic patterns was explored in the eastern English Channel ecosystem, where pelagic-benthic trophic coupling was recently studied empirically. The OSMOSE model was applied to this ecosystem by explicitly representing the life cycle of 13 fish species and one squid group, forced by pelagic and benthic prey fields that are variable over time and space. A matrix defining possible accessibilities between life stages was added to...
Tipo: Text
Palavras-chave: Emergent patterns; Pelagic-benthic coupling; Individual-based model; Food web; Fish community.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00511/62290/66748.pdf

Modeling the impact of oyster culture on a mudflat food web in Marennes-Oleron Bay (France)
Provedor de dados: 5
Autores: Leguerrier, D; Niquil, Nathalie; Petiau, A; Bodoy, Alain.
We used a carbon-based food web model to investigate the effects of oyster cultivation on the ecosystem of an intertidal mudflat. A previously published food web model of a mudflat in Marennes-Oleron Bay, France, was updated with revised parameters, and a realistic surface area and density of existing oyster cultures on the mudflat. We developed 2 hypothetical scenarios to estimate the impact of oyster cultivation on the food web structure of the ecosystem: one with no oysters, the other with a doubled area devoted to cultivated oysters in the bay. Oysters are direct trophic competitors of other filter feeders, and their presence modifies benthic-pelagic coupling by forcing a shift from pelagic consumers to benthic consumers. Increasing the surface area of...
Tipo: Text
Palavras-chave: Carbon flux; Inverse analysis; Food web; Network analysis; Bivalve culture.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/00000/10816/7583.pdf

Numerical analysis of the food web of an intertidal mudflat ecosystem on the Atlantic coast of France
Provedor de dados: 5
Autores: Leguerrier, Delphine; Niquil, Nathalie; Boileau, N; Rzeznik, J; Sauriau, Pierre-guy; Le Moine, Olivier; Bacher, Cedric.
Food web modelling is an ideal way to describe ecosystems, because it accounts for the totality of the relationships between its various components. One difficulty of such an approach, however, lies in the lack of data and information about some ecological relationships, resulting in under-defined systems. Inverse analysis can serve to complete steady-state food webs where the number of direct flow measurements is insufficient relative to the actual number of flows. We applied this method to the intertidal mudflat ecosystem of Brouage (eastern Marennes-Oleron Bay, SW France) and estimated the annual average carbon flows between the compartments of a coupled benthic and pelagic trophic food web from primary producers (microphytobenthos and phytoplankton) to...
Tipo: Text
Palavras-chave: Network analysis; Food web; Inverse analysis; Carbon flow.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/2003/publication-3134.pdf

Implementation of an end-to-end model of the Gulf of Lions ecosystem (NW Mediterranean Sea). I. Parameterization, calibration and evaluation
Provedor de dados: 5
Autores: Bănaru, Daniela; Diaz, Fréderic; Verley, Philippe; Campbell, Rose; Navarro, Jonathan; Yohia, Christophe; Oliveros-ramos, Ricardo; Mellon, Capucine; Shin, Yunne-jai.
An end-to-end model named OSMOSE-GoL has been built for the Gulf of Lions, the main French Mediterranean fishing area. This spatialized dynamic model links the coupled hydrodynamic and biogeochemical model Eco3M-S/SYMPHONIE (LTL – low trophic level model) to OSMOSE (HTL – high trophic level model). It includes 15 compartments of living organisms, five from the LTL model (i.e. nanophytoplankton, microphytoplankton, nanozooplankton, microzooplankton and mesozooplankton) and ten from the HTL model (northern krill, southern shortfin squid, European pilchard, European anchovy, European sprat, Atlantic horse mackerel, Atlantic mackerel, blue whiting, European hake and Atlantic bluefin tuna). With the exception of northern krill and European sprat, all HTL...
Tipo: Text
Palavras-chave: Ecosystem modeling; Food web; Fisheries; OSMOSE; Eco3M.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00487/59860/65525.pdf

Stable isotope ratios in bentho-demersal biota along a depth gradient in the bay of biscay: A multitrophic study
Provedor de dados: 5
Autores: Schaal, Gauthier; Nerot, Caroline; Grall, Jacques; Chouvelon, Tiphaine; Lorrain, Anne; Mortillaro, Jean-michel; Savoye, Nicolas; Brind'Amour, Anik; Paulet, Yves-marie; Le Bris, Herve.
Although stable isotope ratios are increasingly used to investigate the trophic ecology of marine organisms, their spatial variations are still poorly understood in the coastal environment. In this study, we measured the stable isotope composition (δ13C, δ15N) of suspended particulate organic matter (SPOM) (primary producer), a suspension feeder, the great scallop Pecten maximus (primary consumer), megabenthic decapods and benthic fishes (secondary consumers) along a depth gradient (from 5m to 155m depth) across the continental shelf of the Bay of Biscay. Although the three trophic levels exhibited similar δ13C patterns along the gradient, the δ15N patterns varied between SPOM, scallops and carnivores. The δ15N difference between SPOM and scallops...
Tipo: Text
Palavras-chave: Trophic; Coastal; Bivalves; Food web; Bay of Biscay.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00288/39921/38481.pdf

Calibrating process-based marine ecosystem models: An example case using Atlantis
Provedor de dados: 5
Autores: Pethybridge, Heidi; Weijerman, Mariska; Perrymann, Holly; Audzijonyte, Asta; Porobic, Javier; Mcgregor, Vidette; Girardin, Raphael; Bulman, Cathy; Ortega-cisneros, Kelly; Sinerchia, Matteo; Hutton, Trevor; Lozano-montes, Hector; Mori, Mao; Novaglio, Camilla; Fay, Gavin; Gorton, Rebecca; Fulton, Elizabeth.
Calibration of complex, process-based ecosystem models is a timely task with modellers challenged by many parameters, multiple outputs of interest and often a scarcity of empirical data. Incorrect calibration can lead to unrealistic ecological and socio-economic predictions with the modeller’s experience and available knowledge of the modelled system largely determining the success of model calibration. Here we provide an overview of best practices when calibrating an Atlantis marine ecosystem model, a widely adopted framework that includes the parameters and processes comprised in many different ecosystem models. We highlight the importance of understanding the model structure and data sources of the modelled system. We then focus on several model outputs...
Tipo: Text
Palavras-chave: Best practices; Model diagnostics; Food web; Pedigree; Parameter estimation.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00516/62723/67160.pdf

Dietary breadth and trophic position of introduced European catfish Silurus glanis in the Tarn River (Garonne River basin), southwest France
Provedor de dados: 5
Autores: Syvaeranta, Jari; Cucherousset, Julien; Kopp, Dorothee; Crivelli, Alain; Cereghino, Regis; Santoul, Frederic.
Although being a widely introduced and successfully established species, the European catfish Silurus glanis L. (the world’s third largest freshwater fish) remains poorly studied in its introduced areas. Here we studied the trophic ecology of non-native European catfish in a large river system in south-western France using stomach content and stable isotope analyses (SIA). We used fin samples for SIA of catfish and hence tested the validity of using fin tissue as a proxy for muscle in SIA. The mean δ15N and δ13C values analysed from fin tissues did not differ from those analysed from muscle tissue and reflected strong and consistent relationships (r2 = 0.95 for carbon and r2 = 0.98 for nitrogen). The δ15N values varied almost 5‰ among the analysed catfish...
Tipo: Text
Palavras-chave: Stable isotopes; Introduced species; Top predator; River; Food web; Fin clips.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00168/27896/26159.pdf

Modelling the Mediterranean marine ecosystem as a whole: addressing the challenge of complexity
Provedor de dados: 5
Autores: Piroddi, Chiara; Coll, Marta; Steenbeek, Jeroen; Moy, Diego Macias; Christensen, Villy.
An ecosystem modelling approach was used to understand and assess the Mediterranean marine ecosystem structure and function as a whole. In particular, 2 food web models for the 1950s and 2000s were built to investigate: (1) the main structural and functional characteristics of the Mediterranean food web during these 2 time periods; (2) the key species/functional groups and interactions; (3) the role of fisheries and their impact; and (4) the ecosystem properties of the Mediterranean Sea in comparison with other European regional seas. Our results show that small pelagic fishes, mainly European pilchards and anchovies, prevailed in terms of biomasses and catches during both periods. Large pelagic fishes, sharks and medium pelagic fishes played a key role in...
Tipo: Text
Palavras-chave: Ecopath model; Food web; Ecosystem modelling; Network analysis; Fishing impact; Mediterranean Sea.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00626/73838/73681.pdf

Comparative analysis of the food webs of two intertidal mudflats during two seasons using inverse modelling: Aiguillon Cove and Brouage Mudflat, France
Provedor de dados: 5
Autores: Degre, Delphine; Leguerrier, D; Du Chatelet, E; Rzeznik, J; Auguet, Jean-christophe; Dupuy, Christine; Marquis, E; Fichet, Denis; Struski, Caroline; Joyeux, E; Sauriau, Pierre-guy; Niquil, Nathalie.
Inverse analysis was used to model the food webs of two intertidal mudflat ecosystems: Aiguillon Cove (AC) and Brouage Mudflat (BM) (south-western Atlantic coast, France). The aim of the present study is to describe and compare the functioning of these two ecosystems. The method of inverse analysis has been adapted in order to take into account, in a single calculation, two seasons: spring/summer (mid-March to mid-October) and autumn/winter (the rest of the year). Gathering all available data on the two sites, the most important gaps in knowledge were identified with the help of sensitivity analyses: they concerned mainly the exports of material by grazing fish (such as mullet Liza ramada), resuspension of microphytobenthos, and fluxes linked to microfauna...
Tipo: Text
Palavras-chave: Atlantic coast; Sensitivity analysis; Tidal flat; Inverse analysis; Steady state; Food web.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1863.pdf

Trophic importance of diatoms in an intertidal Zostera noltii seagrass bed: Evidence from stable isotope and fatty acid analyses
Provedor de dados: 5
Autores: Lebreton, Benoit; Richard, Pierre; Galois, Robert; Radenac, Gilles; Pfleger, Camille; Guillou, Gael; Mornet, Francoise; Blanchard, Gerard F.
A current predominant paradigm emphasizes the role of epiphytic algae for invertebrates in most seagrass food webs. However, in some intertidal Zostera noltii beds, epiphyte biomass is very low compared to microphytobenthos and seagrass biomasses. We assessed the role of microphytobenthos in a temperate intertidal Z. noltii bed by combining stable isotope and fatty acid (FA) analyses on primary producers, composite sources suspended particulate organic matter (SPOM) and sediment surface organic matter (SSOM) and the main macrofaunal consumers. Z. noltii showed high delta C-13 (-9.9 parts per thousand) and high 18:2(n-6) and 18:3(n-3) contents. Microphytobenthos was slightly more C-13-depleted (-15.4 parts per thousand) and had high levels of diatom...
Tipo: Text
Palavras-chave: Food web; Intertidal seagrass bed; Microphytobenthos; Zostera noltii; Stable isotope ratio; Fatty acid profiles; European Atlantic coast.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00035/14640/12051.pdf

Diversity and stability of an estuarine trophic network
Provedor de dados: 5
Autores: Lobry, Jeremy; David, V; Pasquaud, S; Lepage, M; Sautour, B; Rochard, E.
Estuarine areas provide highly valuable ecosystem benefits for human populations, despite being under intense demographic, economic and ecological pressures. Hence, an understanding of the structure and function of estuarine ecosystems is essential for understanding the persistence and stability of these ecosystems and their response to perturbations. This study synthesises available data and knowledge about the Gironde estuary (SW France) in a mass-balanced trophic model to illustrate potential key patterns in the functioning of the estuarine ecosystem and key elements of its stability. In order to evaluate the total direct and indirect impact on the whole community of the 2 main sources of anthropogenic perturbations in the estuarine area, mortalities...
Tipo: Text
Palavras-chave: Gironde estuary; Ecopath; Diversity; Stability; Network analysis; Food web; Estuarine ecosystem.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4290.pdf

Réseau trophique de l'anse de l'Aiguillon : dynamique et structure spatiale de la macrofaune et des limicoles hivernants
Provedor de dados: 5
Autores: Degre, Delphine.
The Aiguillon Cove has been preserved as Natural Reserves since 1996 and 1999 for its international importance as wintering areas for waterbirds. The benthic communities of this a macrotidal bay were still little studied. In order to understand the spatial pattern and the dynamics of the main compartments of its trophic network, two cartographies were carried out at the time of the departure (March) and the arrival (October) of the waders. A monthly study was carried out too in three stations of the upper mudflat. The spatio-temporal homogeneity of the granulometry of the sediments and the strong seasonal variation of the salinity of pore water were highlighted. The molluscs' diversity is low, especially on the upper mudflat where abundance of Hydrobia...
Tipo: Text
Palavras-chave: Carrying capacity; Inverse analysis; Spatio temporal patterns; Food web; Isotope; Waders; Molluscs bivalves; Aiguillon Cove; Capacité d'accueil; Analyse inverse; Dynamique des populations; Structure spatiale; Réseau trophique; Isotope; Limicoles; Bivalves; Mollusques; Anse de l'Aiguillon.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/these-2097.pdf

Diversité structurelle et fonctionnelle des peuplements sablo-vaseux de Bretagne sud : Impact de l'expansion d'Haploops nirae
Provedor de dados: 5
Autores: Rigolet, Carine.
This thesis aims here, based on the case of the Bay of Concarneau, to understand the impact of the development of dense populations of the tubiculous amphipod Haploops nirae on the structural and functional diversity of sandy-mud communities of South Brittany. The study of Haploops communities was developed on various levels of organization of life, from the specific role of Haploops nirae to functional role of Haploops community in the ecosystem passing through the description of the community composition and its role on the biodiversity. Our results suggest firstly that the functional role of Haploops nirae alone (filtration pressure, secondary production) is potentially important. Moreover, the physical changes induced by Haploops were found to have...
Tipo: Text
Palavras-chave: Ampeliscidae; Réseau trophique; Diversité fonctionnelle; Macrofaune benthique; Diversité; Bretagne Sud; Espèce ingénieure; Ampeliscidae; Benthic macrofauna diversity; Food web; Functional diversity; Engineer species; South Brittany.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00134/24549/22582.pdf

The mosaic of habitats of the Seine estuary: Insights from food-web modelling and network analysis
Provedor de dados: 5
Autores: Tecchio, Samuele; Rius, Antonio; Dauvin, Jean-claude; Lobry, Jeremy; Lassalle, Geraldine; Morin, Jocelyne; Bacq, Nicolas; Cachera, Marie; Chaalali, Aurelie; Villanueva, Ching-maria; Niquil, Nathalie.
Ecological network analysis was applied in the Seine estuary ecosystem, northern France, integrating ecological data from the years 1996 to 2002. The Ecopath with Ecosim (EwE) approach was used to model the trophic flows in 6 spatial compartments leading to 6 distinct EwE models: the navigation channel and the two channel flanks in the estuary proper, and 3 marine habitats in the eastern Seine Bay. Each model included 12 consumer groups, 2 primary producers, and one detritus group. Ecological network analysis was performed, including a set of indices, keystoneness, and trophic spectrum analysis to describe the contribution of the 6 habitats to the Seine estuary ecosystem functioning. Results showed that the two habitats with a functioning most related to a...
Tipo: Text
Palavras-chave: Trophic network; Estuary; Ecological network analysis; Ecopath with Ecosim; Food web; Ecosystem health indicators.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00270/38154/42026.pdf

Spatial distribution and nutritional requirements of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) in a Mediterranean Nanozostera noltii (Hornemann) meadow
Provedor de dados: 5
Autores: Rossi, Francesca; Colao, Elodie; Jose Martinez, Maria; Klein, Judith C.; Carcaillet, Frederique; Callier, Myriam; De Wit, Rutger; Caro, Audrey.
Sulphur-oxidising endosymbiont-bearing bivalves often inhabit seagrass meadows, where they can control sulphide levels and variably contribute to carbon cycling, by feeding on endosymbiotic bacteria and/or on particulate organic matter from the water column. The patterns of variability in their feeding mode and their spatial distribution within the seagrass meadows are however poorly studied. Seagrass beds form naturally patchy habitats with seagrass-sand edges that may have variable effects on different organisms. The present study aims at understanding differences in feeding mode and abundance of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) as well as the physiological conditions of its endosymbiotic populations between edge and...
Tipo: Text
Palavras-chave: Bivalve; Food web; Mediterranean; Seagrass; Stable isotopes; Symbiosis.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00138/24911/26373.pdf

Effects of alga Fucus serratus decline on benthic assemblages and trophic linkages at its retreating southern range edge
Provedor de dados: 5
Autores: Duarte, Linney; Rossi, Francesca; Docal, Cristina; Viejo, Rosa M.
Canopy-forming seaweeds are important coastal ecosystem engineers that sustain diverse multi-trophic assemblages. Their losses, with the subsequent reduction in habitat complexity, have been documented across many parts of the world and are often attributed to climate change and other anthropogenic factors. The general aim of the present study was to understand the repercussions of the decline of the canopy-forming alga Fucus serratus L. at its retreating southern range edge in the diversity and food-web linkages of intertidal assemblages. Few studies have attempted to document changes in benthic food webs following canopy loss. We examined the differences among southern locations situated at different distances from the range margin: those at the very...
Tipo: Text
Palavras-chave: Canopy-forming algae; Fucus serratus; Rear range edge margin; Delta N-15; Delta C-13; Stable isotope analysis; Food web.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00626/73845/73611.pdf

Gape size influences seasonal patterns of piscivore diets in three Neotropical rivers
Provedor de dados: 83
Autores: Montaña,Carmen G.; Layman,Craig A.; Winemiller,Kirk O.
We examined diets of four piscivores, two in the order Perciformes (Cichla temensis and C. orinocensis) and two in the order Characiformes (Boulengerella cuvieri and B. lucius), from the Cinaruco, La Guardia, and Ventuari rivers in Venezuela throughout the wet-dry seasonal cycle. The four piscivores consumed a phylogenetically and morphologically diverse group of fishes, reflecting the overall diversity of fish species in these rivers. At the start of the falling-water period, Cichla consumed large prey, especially the abundant, migratory, fish of the genus Semaprochilodus. As these relatively large prey became depleted during the dry season, Cichla tended to consume smaller prey. For Boulengerella, gape limitation precluded consumption of larger,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Floodplain river; Food web; Optimal foraging theory; Predator-prey interaction; Venezuela.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000300018

Body condition and energy density of juvenile streaked prochilod Prochilodus lineatus (Valenciennes, 1837) in a Neotropical floodplain
Provedor de dados: 83
Autores: Corbetta,Daiany de Fátima; Veronezzi,Ana Lúcia; Benedito,Evanilde.
ABSTRACT Variations in energetic density (E  D ) and the relative condition factor (K  n ) of juveniles of Prochilodus lineatus were investigated to identify whether these two variables respond similarly to environmental factors. We hypothesized that fluviometric levels in different sub-basins of the Upper Paraná River floodplain positively influence the E  D and K  n of juvenile fish. Temporally, the values of E  D and K  n were linked more directly to the dynamics of the flood pulses on the plain. Spatially, the lowest values of E  D and K  n were observed in the environment that was directly affected by the operation of dams, the sub-basin Paraná. Although the energy density and condition factor did not show similar results for juveniles in some of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Condition Factor; Food web; Habitat; Impact; Paraná basin.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000400201

Stable isotope evidence for trophic overlap of sympatric Mexican Lake Chapala silversides (Teleostei: Atherinopsidae: Chirostoma spp.)
Provedor de dados: 83
Autores: Mercado-Silva,Norman; Lyons,John; Moncayo-Estrada,Rodrigo; Gesundheit,Pablo; Krabbenhoft,Trevor J.; Powell,Daniel L.; Piller,Kyle R.
We explore the trophic role that a diverse sympatric group of fishes in the genus Chirostoma play in a large, shallow lake in central Mexico, Lake Chapala. We use δ13C and δ15N stable isotope - based food web analyses to explore how they relate to other components of the Lake Chapala ecosystem. We find five Chirostoma species in top trophic levels of the Chapala food web compared to other fishes, relying on a combination of zooplankton, fish and benthic resources as energy sources. Food web metric analyses showed generally overlapping trophic niches for members of Chirostoma, especially in terms of δ13C. However, C. jordani had lower mean δ15N isotopic values than C. promelas. As a group, "pescados blancos" (C. sphyraena and C. promelas) also had higher...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Charales; Food web; Menidini; Pescadoblanco; Shallow lake.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000200389

Modeling energy flow in a large Neotropical reservoir: a tool do evaluate fishing and stability
Provedor de dados: 83
Autores: Angelini,Ronaldo; Agostinho,Angelo Antonio; Gomes,Luiz Carlos.
Recently, there is an increasing perception that the ecosystem approach gives important insights to support fisheries stock assessment and management. This paper aims to quantify energy flows in the Itaipu Reservoir (Brazil) and to simulate increase of the fishing effort of some species, using Ecopath with Ecosim software, which could allow inferences on stability. Therefore, two steady-state Itaipu models were built (1983-87 and 1988-92). Results showed that: a) there are no differences between models, and results on aging trends do not vary over time indicating that fishery does not alter the ecosystem as a whole; b) results of fisheries simulations are approximate to mono-specific stock assessment for the same species and periods; c) many authors...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ecopath; Food web; Fisheries; Ecosystem; Simulation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000200011

Variability of δ13C and δ15N in three zooplankton species from the Upper Paraná River floodplain
Provedor de dados: 103
Autores: Santana,Ana R. A.; Lansac-Tôha,Fabio Amodêo; Benedito,Evanilde.
This study evaluated the isotopic composition of three zooplankton species - Notodiaptomus amazonicus (Wright, 1935), Moina minuta Hansen, 1899 and Bosmina hagmanni Stingelin, 1904 - from the Upper Paraná River floodplain. We predicted that there would be isotopic variability among species in the different sampled environments. Samplings were conducted in three lakes from the Baía subsystem and in two lakes from the Paraná subsystem. At each location, some abiotic variables were measured, and zooplankton (3 to 4) and phytoplankton (3) samples were taken. The species sampled did not present significant differences between subsystems; however, they were different among the lakes, with variations of about 10.8‰ for δ13C and 5.8‰ for δ15N. The isotopic values...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Food web; Limnology; Phytoplankton; Energy; Stable isotopes.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000400017

Influence of substrate on the richness and composition of Neotropical cave fauna
Provedor de dados: 42
Autores: ZEPON,TAMIRES; BICHUETTE,MARIA ELINA.
ABSTRACT The food base in the subterranean environment consists mainly of allochthonous materials. In this environment the resources are distributed generally in a heterogeneous dispersed way and the distribution of resources and their availability determine where the terrestrial invertebrates will reside, which is important for understanding ecological relationships and to establish conservation strategies. Thus, we tested how the complexity of substrates influences the richness and composition of the subterranean terrestrial invertebrates in the Presidente Olegário karst area, southeastern Brazil. We carried out collections in six caves during both dry and wet seasons, using combined collection methods. We observed different distributions in relation to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Brazil; Communities; Conservation; Food web; Terrestrial invertebrates; Trophic resources.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652017000401615

Spatial variation in the stable isotopes of 13C and 15N and trophic position of Leporinus friderici (Characiformes, Anostomidae) in Corumbá Reservoir, Brazil
Provedor de dados: 42
Autores: Pereira,Alexandre L.; Benedito,Evanilde; Sakuragui,Cássia M.
Stable isotopes of carbon (delta13C) and nitrogen (delta15N) were used to describe sources of energy and trophic position for adult Leporinus friderici in the area of the Corumbá Reservoir, Brazil. Samples were collected from April 1999 to March 2000. Spatial variations were not identified in the isotopic composition. The maximum and minimum contribution of C4 plants calculated integrating the variation of plants and fish were 47.7% and 2.4%, respectively. Among C3 plants, periphyton presented closer isotopic values to those observed for fishes, corresponding to an important carbon source. The proportion of ingested plant item is larger in rivers upstream from the reservoir (42.7%), which justifies the smaller trophic level among there. However, in the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Stable isotopes; Reservoir; Leporinus friderici; Food web.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652007000100006

Isotopic variation among Amazonian floodplain woody plants and implications for food-web research
Provedor de dados: 49
Autores: Correa,Sandra Bibiana; Winemiller,Kirk; Cárdenas,Dairon.
Isotopic variation within food sources adds uncertainty to models intended to reconstruct trophic pathways. Understanding this variation is pivotal for planning sampling protocols for food-web research. This study investigates natural variation in C and N stable isotopes among plant species in two western Amazon flooded forests with contrasting watershed biogeochemistry (white-water várzea-forest and black-water igapó-forest). Our objectives were to compare δ13C and δ15N of leaves and fruits between sites; assess the magnitude of within-site variation in δ13C and δ15N of leaves (várzea: 28 spp., igapó: 10 spp.) and fruits (várzea: 22 spp., igapó: 22 spp.); determine within-plant variation in δ13C and δ15N of leaf, wood and fruit tissues; and test whether...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Stable isotopes; Igapó; Várzea; Fruits; Food web; Mixing model.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032016000200207