Consulta: subjectFacets:"Trophic levels"
Registros recuperados: 14
Data/hora: 01/06/2024 17:52:45

Visualizing the Food-Web Effects of Fishing for Tunas in the Pacific Ocean
Provedor de dados: 7
Autores: Hinke, Jefferson T; Pacific Fisheries Environmental Laboratory and Joint Institute for Marine and At; jhinke@pfeg.noaa.gov; Kaplan, Isaac C; Center for Limnology, University of Wisconsin; ickaplan@wisc.edu; Aydin, Kerim; Alaska Fisheries Science Center; Kerim.Aydin@noaa.gov; Watters, George M; Pacific Fisheries Environmental Laboratory; gwatters@pfeg.noaa.gov; Olson, Robert J; Inter-American Tropical Tuna Commission; rolson@iattc.org; Kitchell, James F. K.; Center for Limnology, University of Wisconsin; kitchell@mhub.limnology.wisc.edu.
We use food-web models to develop visualizations to compare and evaluate the interactions of tuna fisheries with their supporting food webs in the eastern tropical Pacific (ETP) and the central north Pacific (CNP) Oceans. In the ETP and CNP models, individual fisheries use slightly different food webs that are defined by the assemblage of targeted tuna species. Distinct energy pathways are required to support different tuna species and, consequently, the specific fisheries that target different tuna assemblages. These simulations suggest that catches of tunas, sharks, and billfishes have lowered the biomass of the upper trophic levels in both systems, whereas increases in intermediate and lower trophic level animals have accompanied the decline of top...
Tipo: Peer-Reviewed Reports
Palavras-chave: Ecosystem modeling; Food webs; Longline fishing; Purse-seine fishing; Tunas; Trophic levels; Pacific Ocean.
Ano: 2004

Relative abundance and autecology of three piscivorous fishes in lakes of the upper basin of Salado River (Buenos Aires Province, Argentina)
Provedor de dados: 67
Autores: Barla,María J; Vera,María S; O'Brien,Emma D.
The Salado River is an important watercourse in northern Pampean region of Argentina which includes several lakes in the upper part of its basin. This upper part shows lesser fish species richness than the lower section of the river. In this paper, an analysis of community structure of secondary and tertiary consumers and its autecology are presented. Among the 14 fish species recorded, 3 were mainly or totally piscivorous as adults. They constituted 11.4% of the numeric abundance and 10.8% of the biomass. Their numeric abundance was 89% (Oligosarcus jenynsii), 11% (Rhamdia sapo), and 0.5% (Hoplias malabaricus malabaricus), and their relative biomass was 61%, 33%, and 6%, respectively. Length/weight ratio, condition factor, and cephalic index indicate that...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Characiformes; Siluriformes; Predation; Biocenology; Lentic environments; Pampean lakes; Trophic levels.
Ano: 2003
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2003000200009

L'alimentation de Diplodus annualris, Diplodus sargus, Diplodus vulgaris et Sparus aurata (Pisces, Sparidae) dnas le golfe du Lion et les lagunes littorales.
Provedor de dados: 5
Autores: Rosecchi, E.
The four Sparidae studied are coastal species that regularly enter the Mediterranean coastal salt lagoons. Changes in diet with regard to size class of fish, and occasionally season, are detailed. For each species, diets in the sea and in the lagoons are compared using several methods and show differences. Individuals from lagoons do not eat, or in very low numbers, mollusks, echinoderms and decapods. However, as their feeding is very rich and diverse, sparid fishes can probably find in the lagoons, whatever their age, the prey necessary to their growth. Trophic factors cannot explain age structure in lagoons and the absence of some age classes.
Tipo: Text
Palavras-chave: Pisces; Sparidae; Trophic levels; Age composition; Predation.
Ano: 1985
URL: http://archimer.ifremer.fr/doc/1985/publication-1774.pdf

Estructura de la comunidad bentónica y ecología trófica de Scianeidae (Pisces: Osteichthyes) en el estuario del Río de la Plata
Provedor de dados: 20
Autores: Giberto, D.A.
Benthic communities of the Río de la Plata estuary and their trophic link with Micropogonias furnieri, Paralonchurus brasiliensis, Menticirrhus americanus, Cynoscion guatucupa, Macrodon ancylodon and Umbrina canosai, six species of the Sciaenidae Family, were studied. Benthic composition was characterized using 122 sampling sites between 1999 and 2005. Multivariate and univariate statistical tools were used to analyze diversity, abundance and biomass patterns. A total of 370 taxa were found at the study area. Four areas were established using benthic composition: Inner Río de la Plata (RdP), middle RdP, outer RdP and Marine zone. Higher abundance (9,877 ind/m2) and biomass (1,456.8 g/m2) values were found at middle RdP. Nephtys fluviatilis, Heteromastus...
Tipo: Theses and Dissertations
Palavras-chave: Benthos; Estuarine organisms; Brackishwater environment; Feeding behaviour; Food organisms; Trophic levels; Stomach content; Trophic levels; Benthos; Feeding behaviour; Brackishwater environment; Http://aims.fao.org/aos/agrovoc/c_7969; Http://aims.fao.org/aos/agrovoc/c_878; Http://aims.fao.org/aos/agrovoc/c_10778; Http://aims.fao.org/aos/agrovoc/c_1050.
Ano: 2008
URL: http://hdl.handle.net/1834/2952

Distribución del primer  nivel trófico (fitoplancton) en el Pacífico ecuatoriano, período 1996-1997 (pre-El Niño)
Provedor de dados: 20
Autores: Tapia, M.E.; Torres, G.
Este artículo describe las condiciones bio-oceanográficas del primer nivel trófico, distribución y concentración de la biomasa fitoplanctónica (clorofila "a") y contajes celulares) a nivel superficial y subsuperficial de la capa fótica a los 75 m. de profundidad, se da la distribución de especies indicadoras del fitoplancton y su relación con las variables de temperatura y nutrientes, registrados en tres cruceros oceanográficos realizados en octubre/1996, abril-mayo/1997 y agosto/1997.
Tipo: Journal Contribution
Palavras-chave: Distribution; Biomass; Chlorophylls; Phytoplankton; Indicator species; El Nino phenomena; Trophic levels; Multiship expeditions; Distribution; Biomass; Phytoplankton; Trophic levels; Chlorophylls; Indicator species.
Ano: 1998
URL: http://hdl.handle.net/1834/2280

Tramas tróficas en sistemas frontales del Mar Argentino: estructura, dinámica y complejidad analizada mediante isótopos estables
Provedor de dados: 20
Autores: Gaitán, E.N.
Two of the most important frontal systems of the Argentine Sea (SW Atlantic Ocean) were compared to obtain evidences on the regulatory mechanisms of food web length, incorporating both spatial (areas within fronts) and temporal (presence or absence of frontal structure) variability. The stable isotopes of Carbon and Nitrogen were used to evaluate the origin and composition of the organic matter used by primary consumers, the structure of food webs, the trophic levels of several taxa and the benthic-pelagic coupling within each system. In the Río de la Plata estuarine front, different sources of organic matter would support the food webs occurring in the three areas of the system. The particulate organic material (POM) would be the main resource supporting...
Tipo: Theses and Dissertations
Palavras-chave: Food webs; Trophic relationships; Trophic levels; Saline fronts; Estuarine front; Carbon isotopes; Nitrogen isotopes; Plankton; Benthos; Brackishwater fish; Marine fish; Brackishwater environment; Marine environment.
Ano: 2012
URL: http://hdl.handle.net/1834/4523

Ecología trófica del lenguado Paralichthys patagonicus (Jordan, 1889) en el Ecosistema Costero Argentino-Uruguayo
Provedor de dados: 20
Autores: Troccoli, G.H.
Se determinaron los hábitos alimentarios y la composición de la dieta del lenguado patagónico Paralichthys patagonicus (Jordan, 1889) a partir de análisis cualitativos y cuantitativos del contenido estomacal. Los ejemplares provinieron de 16 muestreos de desembarque de la flota comercial realizados entre febrero de 2009 y abril de 2010 en el puerto de Mar del Plata (Prov. Buenos Aores, Argentina). Se analizaron un total de 828 lenguados de los cuales el 61,8% (512) fueron hembras y 36,7% (304) machos. Del total de estómagos analizados, el 32,9% (272) presentó alimento (184 hembras y 84 machos). Paralichthys patagonicus es un predador ictiófago de amplio espectro trófico (20 ítems presas). Anchoíta (Engraulis anchoita) fue la presa más consumida, seguida...
Tipo: Theses and Dissertations
Palavras-chave: Feeding behaviour; Trophic levels; Predator prey interactions; Population structure; Stomach content; Paralichthys patagonicus; Marine environment.
Ano: 2011
URL: http://hdl.handle.net/1834/4522

Índice microbiológico para evaluar el estado trófico de las aguas de la plataforma SW cubana
Provedor de dados: 20
Autores: Miravet Regalado, M.E.; Lugioyo Gallardo, M.; Rodríguez Acosta, F.
There are different microbiological indexes to evaluate the trophic state of inland and coastal waters based on the direct relation between the concentration of organic matter and the heterotrophic bacteria. These indexes are valuable; however, as they were determined starting from data collected in tempered latitudes, if they are applied to tropical regions where heterotrophic bacteria concentrations are usually higher, the results can be underestimated. The objective of the present work is to elaborate a quantitative index to evaluate the trophic state from microbiological data collected in waters of the SW Cuban shelf. For this purpose, values of concentrations of heterotrophic (HB) and sulfate-reducing (SR) bacteria obtained in waters of SW Cuban shelf...
Tipo: Journal Contribution
Palavras-chave: Trophic levels; Shelf geology; Trophic levels; Http://aims.fao.org/aos/agrovoc/c_7969.
Ano: 2009
URL: http://hdl.handle.net/1834/3496

Ecología trófica de la pescadilla de red, Cynoscion guatucupa (Pisces: Sciaenidae), en aguas del Atlántico sudoccidental.
Provedor de dados: 20
Autores: García, S.
Trophic spectrum of Cynoscion guatucupa (striped weakfish) was analyzed through stomach content of individuals coming from two areas of Buenos Aires coast (38° 30'S - 41° 30'S): Argentine - Uruguayan Fishing Common Zone (AUFCZ) and El Rincón area (Argentine Sea, SW Atlantic). The stomach contents of 3323 individual captured in research cruises carried out during 2004 and 2005 was determined. In the diet 39 prey items were identified corresponding to 4 Phyla. Trophic spectrum was determined with Index of Relative Importance (IRI), where fishes were the principal prey (72,53 percentage IRI), crustaceans were secondary prey (27,44 percentage IRI) and with minor values polychaetes and mollusk (0,2 percentageIRI) were found. Pelagic fish was the predominant...
Tipo: Theses and Dissertations
Palavras-chave: Feeding behaviour; Trophic levels; Stomach content; Food consumption; Predation; Food organisms; Shared stocks; Feeding behaviour; Trophic levels; Food consumption; Predation; Http://aims.fao.org/aos/agrovoc/c_10778; Http://aims.fao.org/aos/agrovoc/c_7969; Http://aims.fao.org/aos/agrovoc/c_3016; Http://aims.fao.org/aos/agrovoc/c_6162.
Ano: 2007
URL: http://hdl.handle.net/1834/3583

Ecología trófica del congrio de profundidad Bassanago albescens (Barnard, 1923) en el Atlántico Sudoccidental (35º'S-45º'S)
Provedor de dados: 20
Autores: Izzo, L.P.
Los hábitos alimentarios del congrio de profundidad Bassanago albescens fueron estudiados por medio del análisis de los contenidos estomacales. Las muestras provinieron de campañas de investigación llevadas a cabo por el Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP) durante el año 2009, en dos zonas de la Plataforma Continental Argentina (Norte: 36°S-41°S y Sur: 44°S-47°S). De los 222 estómagos analizados, 189 (83,78%) contenían alimento, identificándose un total de 34 ítems presa agrupados en 7 categorías. Los valores de %IRI indicaron que la principal categoría presa de la dieta fueron los cefalópodos, seguidos por isópodos y anfípodos. Se estableció la existencia a nivel poblacional de una tendencia hacia una estrategia generalista...
Tipo: Theses and Dissertations
Palavras-chave: Feeding behaviour; Food organisms; Predator prey interactions; Trophic levels; Stomach content; Bassanago albescens; Marine environment.
Ano: 2010
URL: http://hdl.handle.net/1834/5157

Estrategias de vida de los copépodos Drepanopus forcipatus y Calanus australis en relación con los recursos tróficos en la plataforma patagónica austral (Argentina, 47°- 55°S)
Provedor de dados: 20
Autores: Antacli, J.C.
This Thesis contributes to elucidate the life cycle strategies of two copepod species, the medium-size clausocalanid Drepanopus forcipatus Giesbrecht, 1888 and the large calanid Calanus australis Brodsky, 1959, in relation to the environmental conditions in the southern Patagonian shelf (47°-55°S). This research was mainly carried out with samples collected in late summer/early autumn (March/April, 2004) onboard RV "Dr. E. L. Holmberg" (INIDEP, Mar del Plata). An additional sampling performed during early spring (October, 2005) with RV "Puerto Deseado" (CONICET) was also utilized. The present study was based on the following research questions: 1) Which is the available food for copepod populations by late summer? 2) Which is the relative contribution of...
Tipo: Theses and Dissertations
Palavras-chave: Zooplankton; Trophic levels; Population structure; Hydrography; Community composition.
Ano: 2011
URL: http://hdl.handle.net/1834/4205

Ecología trófica del gatuzo, Mustellus schmitti (Springer 1939), en el Mar Argentino
Provedor de dados: 20
Autores: Belleggia, M.
The narrownose smoothhound shark Mustelus schmitti is a benthic shark distributed from Florianópolis (27°S, Brazil) to Deseado River Estuary (47º45´S, Argentina) and occurs from shallow waters to 120m. This Thesis describes the feeding ecology of narrownose smoothhound shark M. schmitti in northern Argentinean Continental Shelf and is structured in four chapters. Chapter 1 contains an introduction and includes purpose, theory and concepts. In Chapter 2, the food habits of M. schmitti were studied based on analysis of stomach contents from specimens collected during the years 2008-2011. Of a total of 959 stomachs sampled during this period, 944 (98,43%) contained food. Prey items were identified to the lowest possible taxonomic level, counted and weighted....
Tipo: Theses and Dissertations
Palavras-chave: Feeding behaviour; Trophic levels; Stomach content; Predator prey interactions; Ontogeny; Shark fisheries; Mustellus schmitti; Polychaeta; Marine environment.
Ano: 2012
URL: http://hdl.handle.net/1834/4775

Les teneurs en composés organochlorés dans les organismes marins de différents niveaux trophiques
Provedor de dados: 27
Autores: Vandamme, K.; Maertens, D.
Polychlorinated biphenyls (PCBs) and some organochlorine pesticides we re measured in some marine organisms of different trophic levels, sampled in the Belgian coastal waters. Because of their persistence and their lipophilic character they accumulate in lipoidal tissues, causing higher organochlorine residue levels in animals with a high adiposity. To compare the residue levels of different organisms lipid based data must be used.The concept of biological magnification controlled by mass transfers of residues through food chains is questioned because predatory fish like cod contained similar or even lower residue levels than organisms of a lower trophic levellike the peacock worm. This supports the concept that the organochlorine levels are controlled by...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Organometallic compounds; Trophic levels.
Ano: 1983
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3259

COMPOSITION, TROPHIC STRUCTURE AND ACTIVITY PATTERNS OF THE UNDERSTORY BATS OF THE BITACO FOREST RESERVE
Provedor de dados: 37
Autores: FERRO MUÑOZ,Natalia; GIRALDO,Alan; MURILLO GARCÍA,Oscar Enrique.
ABSTRACT The present study describes composition and trophic structure, and assesses the effect of environmental temperature and rainfall on the pattern of nocturnal activity of understory bats in an Andean forest, in the first half of the night. Seven sampling events were conducted, lasting six nights each one. Ten mist nets were used to capture bats, which were checked every hour between 18:00 and 00:00 hours. Bat species, sex and capture time were registered. In addition, environmental temperature and rainfall were also recorded during sampling. The bat assemblage of the understory of the study area was represented mostly by frugivore species, within this guild there was a lower richness of nomadic than sedentary species. For the first half of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Environmental temperature; Precipitation; Trophic levels.
Ano: 2018
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2018000200170