Consulta: subjectFacets:"Trophic level"
Registros recuperados: 15
Data/hora: 12/06/2024 01:27:37

Effect of the Puyehue-Cordon Caulle volcanic complex eruption on crustacean zooplankton of Andean lakes
Provedor de dados: 67
Autores: Balseiro,Esteban; Souza,María S.; Serra Olabuenaga,Ignacio; Wolinski,Laura; Bastidas Navarro,Marcela; Laspoumaderes,Cecilia; Modenutti,Beatriz.
We studied the effect of volcanic ash on the crustacean zooplankton (mainly cladocerans) in the Andean North-Patagonian lakes that were affected by the eruption of the Puyehue-Cordón Caulle complex. The study was carried out at three different scales: sub cellular, population and ecosystemic. Cladocerans are filter feeding organisms that cannot distinguish between food (algae less than 30 µm) and suspended ash, therefore when feeding they ingest this material. The ash affected negatively the individuals at a biochemical level, increasing the oxidative stress reacting enzymes like Glutation-S-transferase and the biomarker Acetyl cholinesterase. At the population level, we recorded a decrease in survival and fecundity, in particular, when ash concentration...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Volcanic ash; Cladocerans; Oxidative stress; Survivorship; Trophic level.
Ano: 2014
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2014000100009

Trophic interactions in the coastal ecosystem of Sri Lanka: An ECOPATH preliminary approach
Provedor de dados: 5
Autores: Haputhantri, S; Villanueva, Ching-maria; Moreau, J.
This study attempts to assemble and summarize existing information in order to build a general representation of the trophic interactions within the shallow coastal ecosystem of Sri Lanka. A multispecific ecosystem-based approach on trophic relationships and their possible variations was performed using ECOPATH. Thirty-nine functional groups were considered representing all trophic levels in the food web.   Time-dynamic simulation was carried out using the ECOSIM routine to evaluate the impact of the 1998 El Nino event on key functional groups. Results show that the time needed for any impacted functional group to recover to its initial abundance increased with the trophic level. Two time-series data sets derived from commercial catch and effort statistics...
Tipo: Text
Palavras-chave: Sri Lanka; Indian Ocean; Fisheries management; Feeding relationships; Trophic level; ECOSIM; ECOPATH; Trophic modelling.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3892.pdf

Difference of mercury bioaccumulation in red mullets from the north-western Mediterranean and Black seas
Provedor de dados: 5
Autores: Harmelin-vivien, M.; Cossa, Daniel; Crochet, Sylvette; Banaru, D.; Letourneur, Y.; Mellon-duval, Capucine.
The relationships between total mercury (Hg) concentration and stable nitrogen isotope ratio (delta N-15) were evaluated in Mullus barbatus barbatus and M. surmuletus from the Mediterranean Sea and M. barbatus ponticus from the Black Sea. Mercury concentration in fish muscle was six times higher in the two Mediterranean species than in the Black Sea one for similar sized animals. A positive correlation between Hg concentration and delta N-15 occurred in all species. Increase in Hg concentration with delta N-15 was high and similar in the two Mediterranean fishes and much lower in the Black Sea species. Since this was neither related to trophic level difference between species nor to methylmercury (MeHg) concentration differences between the north-western...
Tipo: Text
Palavras-chave: Black Sea; Mediterranean; Mullidae; Methylmercury; Trophic level; N 15.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6647.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

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

Contrasting perception of fish trophic level from stomach content and stable isotope analyses: A Mediterranean artificial reef experience
Provedor de dados: 5
Autores: Cresson, Pierre; Ruitton, Sandrine; Ourgaud, Melanie; Harmelin-vivien, Mireille.
A large complex of artificial reefs was deployed in the Bay of Marseilles, North-Western Mediterranean, for the enhancement of commercial fisheries stocks. Carbon and nitrogen stable isotope and stomach content analyses were performed on 23 fish species collected on the artificial reefs to assess their trophic position and feeding behaviour. Results indicated that fish diets were not modified on the artificial reefs compared to natural environments, nor was the structure of their trophic network. Artificial reefs, with their complex design, provide diverse and abundant food sources for fishes. Ranges of delta C-13 and delta N-15 of artificial reef fishes were comparable to those recorded in natural Mediterranean environments, with a similar trophic...
Tipo: Text
Palavras-chave: Artificial reefs; Fish diet; NW Mediterranean; Stable isotopes; Stomach content; Trophic level.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00186/29708/28188.pdf

Isotopic analyses, a good tool to validate models in the context of Marine Renewable Energy development and cumulative impacts
Provedor de dados: 5
Autores: Raoux, Aurore; Pezy, Jean-philippe; Ernande, Bruno; Niquil, Nathalie; Dauvin, Jean-claude; Grangeré, Karine.
As part of the energy transition, the French government is planning Offshore Wind Farm (OWF) constructions in the next decades. An integrated ecosystem approach of two future OWF sites of the Eastern English Channel (Courseulles-sur-mer and Dieppe-Le Tréport) was developed to model the marine ecosystems before the OWF implementation. Such ecosystem models allow simulating the possible reef and reserve effects associated to the presence of the farm, and to character the overall changes in the food-web functioning. This holistic view of OWF effects could be replicated on other sites and form the basis of an ecosystem based management of marine renewable energies. However, to use these models for management purpose, they need to be validated. In order to do...
Tipo: Text
Palavras-chave: Offshore wind farm; Ecopath with ecosim; Trophic level; Isotopic nitrogen analysis; English channel.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00611/72359/71273.pdf

Unravelling the ecological role and trophic relationships of uncommon and threatened elasmobranchs in the western Mediterranean Sea
Provedor de dados: 5
Autores: Barria, Claudio; Coll, Marta; Navarro, Joan.
Deficiencies in basic ecological information on uncommon and endangered elasmobranch fishes impair the assessment of their ecological role in marine ecosystems. In this study, we examined the feeding ecology (diet composition and trophic level) and trophic relationships of 22 elasmobranchs (2 Carcharhiniformes, 1 Hexanchiformes, 1 Lamniformes, 3 Myliobatiformes, 6 Rajiformes, 6 Squaliformes and 3 Torpediniformes) present in the western Mediterranean Sea. To obtain a comprehensive view of the feeding ecology of these species, we combined different approaches: stable isotope analyses (delta C-13 and delta N-15 values), stomach content analyses and published sources. Our results revealed differences in feeding strategies among elasmobranch groups: skates...
Tipo: Text
Palavras-chave: Mediterranean Sea; Rays; Sharks; Skates; Species at risk; Stable isotopes; Trophic ecology; Trophic level.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00626/73825/73409.pdf

Investigation of spatiotemporal patterns in mean temperature and mean trophic level of MEDITS survey catches in the Mediterranean Sea
Provedor de dados: 5
Autores: Peristeraki, Panagiota; Bitetto, Isabella; Carbonara, Pierluigi; Carlucci, Roberto; Certain, Gregoire; De Carlo, Francesco; Gristina, Michele; Kamidis, Nikos; Pesci, Paola; Stagioni, Marco; Valls, María; Tserpes, George.
Mean temperature (MTC) and mean trophic level (MTL) spatiotemporal patterns of MEDITS survey catches were examined in 13 geographic statistical areas (GSAs) of the Mediterranean between 1994 and 2016. The study aimed to detect changes in the demersal community structure related to anthropogenic impacts. A generalized additive modelling approach was used to examine the effects of year and GSA on the MTC and MTL indexes and on bottom temperature by haul. For the MTC index, the year was significant only in 4 GSAs, while for MTL it was significant in 5. Higher MTC values were observed in central and eastern areas. Bottom temperature increased after 2010, and also from west to east and from north to south. Our results indicate that the recently observed...
Tipo: Text
Palavras-chave: Mean temperature of the catch; Trophic level; Bottom temperature; Trends; Mediterranean; Fishing pressure; Sea warming; Climate change.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00489/60054/63332.pdf

An ecosystem approach for the assessment of fisheries impacts on marine top predators: the Bay of Biscay case study
Provedor de dados: 5
Autores: Lassalle, Geraldine; Gascuel, Didier; Le Loch, Francois; Lobry, Jeremy; Pierce, Graham John; Ridoux, Vincent; Santos, Maria Begona; Spitz, Jerome; Niquil, Nathalie.
A number of marine mammal populations is currently threatened by their interactions with fisheries. The present study aimed to provide insights into the severity of potential impacts of operational and biological interactions between top predators and fisheries, in the Bay of Biscay region. Our approach was to modify an Ecopath with Ecosim (EwE) model describing the overall structure and function of the ecosystem by including landings and discards of exploited stocks and estimations of the bycatch of non-target compartments. Second, a set of ecological indices and a trophic level (TL)-based model (EcoTroph, ET) were derived from the EwE model. ET was used to simulate the effects of increasing fishing pressure on the ecosystem and, more particularly, on top...
Tipo: Text
Palavras-chave: Ecopath; Ecosystem modelling; EcoTroph; Fisheries impacts; Marine mammals; Trophic level.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00087/19855/17541.pdf

Fishing impact and environmental status in European seas: a diagnosis from stock assessments and ecosystem indicators
Provedor de dados: 5
Autores: Gascuel, Didier; Coll, Marta; Fox, Clive; Guenette, Sylvie; Guitton, Jerome; Kenny, Andrew; Knittweis, Leyla; Nielsen, J. Rasmus; Piet, Gerjan; Raid, Tiit; Travers-trolet, Morgane; Shephard, Samuel.
Stock-based and ecosystem-based indicators are used to provide a new diagnosis of the fishing impact and environmental status of European seas. In the seven European marine ecosystems covering the Baltic and the North-east Atlantic, (i) trends in landings since 1950 were examined; (ii) syntheses of the status and trends in fish stocks were consolidated at the ecosystem level; and (iii) trends in ecosystem indicators based on landings and surveys were analysed. We show that yields began to decrease everywhere (except in the Baltic) from the mid-1970s, as a result of the over-exploitation of some major stocks. Fishermen adapted by increasing fishing effort and exploiting a wider part of the ecosystems. This was insufficient to compensate for the decrease in...
Tipo: Text
Palavras-chave: Ecosystem approach to fisheries management; Ecosystem indicators; Good environmental status; Marine Strategy Framework Directive; Stock assessment; Trophic level.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00201/31256/29910.pdf

Trophic level-based indicators to track fishing impacts across marine ecosystems
Provedor de dados: 5
Autores: Shannon, Lynne; Coll, Marta; Bundy, Alida; Gascuel, Didier; Heymans, Johanna J;; Kleisner, Kristin; Lynam, Christopher; Piroddi, Chiara; Tam, Jorge; Travers-trolet, Morgane; Shin, Yunne.
Trophic level (TL)-based indicators have been widely used to examine fishing impacts in aquatic ecosystems and the induced biodiversity changes. However, much debate has ensued regarding discrepancies and challenges arising from the use of landings data from commercial fisheries to calculate TL indicators. Subsequent studies have started to examine survey-based and model-based indicators. In this paper, we undertake an extensive evaluation of a variety of TL indicators across 9 well-studied marine ecosystems by making use of model- as well as surveyand catch-based TL indicators. Using detailed regional information and data on fishing history, fishing intensity, and environmental conditions, we evaluate how well TL indicators are capturing fishing effects...
Tipo: Text
Palavras-chave: Trophic level; Global comparison; Indicator; Survey; Catch; Ecosystem model; Trophic spectra; Convention on Biological Diversity; Food webs; Ecosystem approach to fisheries.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00222/33361/31768.pdf

Régime alimentaire de poissons carnivores des récifs coralliens de Nouvelle Calédonie
Provedor de dados: 5
Autores: Kulbicki, M; Bozec, Ym; Labrosse, Pierre; Letourneur, Y; Mou-tham, G; Wantiez, L.
A total of 212 carnivorous coastal fish species from New Caledonia, represented by 7335 individuals, were analysed for their diet. Fifty two prey items were identified and later grouped into broader taxonomic categories refered as "prey types". For each fish species 6 biological traits were defined: maximum adult size, major biotope, schooling behaviour, home range, nycthemeral behaviour, degree of crypticity. A general linear model was fit to the diet data taking into account these traits, and depth of capture and fish family. This model was applied to the average number of prey types/stomach and to the volume of 5 prey types: nekton, crustaceans. molluscs, echinoderms, worms. A second analysis was performed on the effect of observed size on diet...
Tipo: Text
Palavras-chave: Coral reefs; Fish diet; Trophic level; Indian ocean.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00608/71965/70663.pdf

Feeding habits of the cockfish, Callorhinchus callorynchus (Holocephali: Callorhinchidae) from off northern Argentina
Provedor de dados: 83
Autores: Roman,Jorge M.; Chierichetti,Melisa A.; Barbini,Santiago A.; Scenna,Lorena B.
ABSTRACT The feeding habits of Callorhinchus callorynchus were investigated in coastal waters off northern Argentina. The effect of body size, seasons and regions was evaluated on female diet composition using a multiple-hypothesis modelling approach. Callorhinchus callorynchus fed mainly on bivalves (55.61% PSIRI), followed by brachyuran crabs (10.62% PSIRI) and isopods (10.13% PSIRI). Callorhinchus callorynchus females showed changes in the diet composition with increasing body size and also between seasons and regions. Further, this species is able to consume larger bivalves as it grows. Trophic level was 3.15, characterizing it as a secondary consumer. We conclude that C. callorynchus showed a behavior of crushing hard prey, mainly on bivalves,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chondrichthyes; Diet; Ontogenetic shifts; Southwest Atlantic; Trophic level.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252020000100202

Use of carbon and nitrogen stable isotopes to study the feeding ecology of small coastal cetacean populations in southern Brazil
Provedor de dados: 49
Autores: Hardt,Fernando Augusto Sliva; Cremer,Marta Jussara; Tonello Junior,Antonio José; Bellante,Antonio; Buffa,Gaspare; Buscaino,Giuseppa; Mazzola,Salvatore; Barreto,André Silva; Martinelli,Luiz Antonio; Zuppi,Giovanni Maria.
Samples from individuals of the populations of Sotalia guianensis (Guiana) and Pontoporia blainvillei (Franciscana) dolphins living in the Babitonga Bay estuary (26° 28′ S/48° 50′ W), and samples from individuals of a second population of P. blainvillei from a nearshore area (26° 38′ S/48° 41′ W), were collected and analyzed along with their prey between 2000 and 2006, to determine the carbon and nitrogen stable isotope ratios and to verify differences in their feeding ecology. No differences were found in the median ð15N values of Guiana (15.2‰) and Franciscana (15.9‰) dolphins living in Babitonga Bay, nor of nearshore Franciscana (15.0‰) individuals, suggesting no variation in the trophic level of these populations. However, the lack of more information...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pontoporia blainvillei; Sotalia guianensis; Babitonga Bay; Feeding ecology; Trophic level.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032013000400090