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Registros recuperados: 45 | |
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McClanahan, Tim; Wildlife Conservation Society; crcp@africaonline.co.ke; Polunin, Nicholas; Newcastle University; n.polunin@ncl.ac.uk; Done, Terry; Australian Institute of Marine Science; t.done@aims.gov.au. |
We review the evidence for multiple ecological states and the factors that create ecological resilience in coral reef ecosystems. There are natural differences among benthic communities along gradients of water temperature, light, nutrients, and organic matter associated with upwelling-downwelling and onshore-offshore systems. Along gradients from oligotrophy to eutrophy, plant-animal symbioses tend to decrease, and the abundance of algae and heterotrophic suspension feeders and the ratio of organic to inorganic carbon production tend to increase. Human influences such as fishing, increased organic matter and nutrients, sediments, warm water, and transportation of xenobiotics and diseases are common causes of a large number of recently reported ecological... |
Tipo: Peer-Reviewed Reports |
Palavras-chave: Carbon production; Coral reefs; Diseases; Ecological stress; Fishing; Global climate change; Keystone species; Oligotrophy-eutrophy; Resilience; Trophic ecology. |
Ano: 2002 |
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Barreto,Silvia B.; Silva,André T.; Souza,Fabiane B.; Jucá-Chagas,Ricardo. |
ABSTRACT Studies on the composition of fish diet and on how species exploit food resources are especially relevant in tropical freshwater systems, where dietary plasticity is a commonly used strategy. In this study, we analysed the food spectrum and the environmental, seasonal and ontogenetic variations in the diet of a characid species [Hemigrammus marginatus Ellis, 1911 (Characidae)] in the region of the Upper Contas River, in the Diamantina Plateau, Brazil. We verified an omnivorous/invertivorous and opportunistic food habit, with predominance of insects and microcrustaceans, followed by filamentous algae. Seasonality did not alter the food resources used by the species. However, differences were detected in the dominant categories when comparing the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feeding; Coastal drainage; Trophic ecology; Freshwater fishes. |
Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212018000100236 |
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Lopes,Vanessa G.; Nessimian,Jorge L.; Da-Silva,Elidiomar R.; Gomes,José Henrique C.; Dias,Ana Carolina I. M.; Souza,Leonardo C.; Branco,Christina W.C.. |
Abstract Food flexibility and omnivory are important features pronounced in Neotropical freshwater fish species, particularly for Astyanax species. Traditionally most fish diet resources are known to be originated in the aquatic environment, however recent studies have pointed to the importance of allochthonous sources. Besides, the colonization of macrophytes, common at several tropical reservoirs, may enhance insectivory in fish diet expanding or concentrating the area of available resources for feeding. Here we employed stomach contents analysis of two sympatric Astyanax species to access the importance of habitat differentiations as spatial complexity in two tropical reservoirs with different environmental features. The NMDS analysis indicated... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feeding resources; Land-water ecotone; Trophic ecology; Ast yanax aff. bimaculatus; Astyanax parahybae. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212016000100212 |
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Bustos,Raimundo L.; Daneri,Gustavo A.; Volpedo,Alejandra V.; Harrington,Ana; Varela,Esperanza A.. |
The South American sea lion, Otaria flavescens (Shaw, 1800) population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%). Raneya brasiliensis (Kaup, 1856) was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829) and Cynoscion guatucupa (Cuvier, 1830) in terms of occurrence (%FO 20.7)... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Trophic ecology; Pinnipedia; Fishes; Cephalopods. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212012000400005 |
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Villanueva, Ching-maria. |
A comparative study of the Sine-saloum (Senegal) and Gambia (The Gambia) estuaries was performed based on trophic model outputs that describe the system structure and functioning. These trophic models were constructed such as to differentiate main energetic flows in the systems and express how climate change may have impacted ecosystem resilience to change. Estuarine fish assemblages are highly resilient despite exposure to vast hydrodynamic variations and stress. Coupled with strong anthropogenic-driven stresses such as fisheries and climate change, ecosystems may undergo severe regime shifts that may weaken their resilience and stability. Taxonomically related and morphologically similar species do not necessarily play similar ecological roles in these... |
Tipo: Text |
Palavras-chave: Complex adaptative systems; Climate change; Food web models; Regime shifts; Ecosystem resilience; Trophic ecology. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00249/36034/34571.pdf |
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Lavaud, Romain; Artigaud, Sebastien; Le Grand, Fabienne; Donval, Anne; Soudant, Philippe; Flye-sainte-marie, Jonathan; Strohmeier, Tore; Strand, Oivind; Leynaert, Aude; Beker, Beatriz; Chatterjee, Arnab; Jean, Fred. |
We combined the use of pigments, fatty acids and sterols as biomarkers of the seasonal variation in food sources of the great scallop Pecten maximus. From March to October 2011, on a biweekly to twice-weekly basis, scallops and seawater from the water column and the water-sediment interface were collected in the Bay of Brest (Brittany, France). Pigment compositions in the seawater and in the stomach and rectum content of the scallops were analyzed by HPLC. Fatty acids and sterols from digestive gland (DG) tissue were analyzed by gas chromatography. Potential relationships between the temporal proportion of each marker in the environment and in the digestive tract were tested using multivariate analysis. Proportions of diatoms and Dinophyceae biomarkers... |
Tipo: Text |
Palavras-chave: Trophic ecology; Food sources; Pigments; Fatty acids; Trophic marker; Phytoplankton; Pecten maximus. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00431/54244/55772.pdf |
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Bonhommeau, Sylvain; Dubroca, Laurent; Le Pape, Olivier; Barde, Julien; Kaplan, David; Chassot, Emmanuel; Nieblas, Anne-elise. |
Trophic levels are critical for synthesizing species' diets, depicting energy pathways, understanding food web dynamics and ecosystem functioning, and monitoring ecosystem health. Specifically, trophic levels describe the position of species in a food web, from primary producers to apex predators (range, 1-5). Small differences in trophic level can reflect large differences in diet. Although trophic levels are among the most basic information collected for animals in ecosystems, a human trophic level (HTL) has never been defined. Here, we find a global HTL of 2.21, i.e., the trophic level of anchoveta. This value has increased with time, consistent with the global trend toward diets higher in meat. National HTLs ranging between 2.04 and 2.57 reflect a... |
Tipo: Text |
Palavras-chave: Human ecology; Nutrition transition; Trophic ecology. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00171/28190/26609.pdf |
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Brosset, Pablo; Le Bourg, Baptiste; Costalago, David; Banaru, Daniela; Van Beveren, Elisabeth; Bourdeix, Jean-herve; Fromentin, Jean-marc; Menard, Frederic; Saraux, Claire. |
Since 2008, a severe decrease in size and body condition together with a demographic truncation has been observed in the sardine (secondarily in anchovy) population of the Gulf of Lions (NW Mediterranean Sea). In parallel, sprat biomass, which was negligible before, has increased tenfold. All of these changes have strongly affected the regional fisheries. Using trophic and isotopic data from contrasting periods of low versus high growth and condition, we investigated potential changes in diet and interspecific feeding interactions through time. Evidence of resource partitioning was found between sprat and both anchovy and sardine in 2004 and 2005. Since 2010, the isotopic niches of the 3 species have tended to overlap, suggesting higher risk of competition... |
Tipo: Text |
Palavras-chave: Trophic ecology; Anchovy; Sardine; Sprat; Dietary overlap; NW Mediterranean. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00347/45822/45540.pdf |
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Kojadinovic, Jessica; Bustamante, Paco; Churlaud, Carine; Cosson, Richard P.; Le Corre, Matthieu. |
Breast feathers were used to estimate mercury levels in six marine birds nesting in the tropical western Indian Ocean, i.e. Sooty Tern (Sterna fuscata), Brown Noddy (Anous stolidus), Lesser Noddy (Anous tenuirostris), Audubon Shearwater (Puffinus lherminieri bailloni), Barau's Petrel (Pterodroma baraui) and the White-tailed Tropicbird (Phaethon lepturus). Juveniles consistently showed lower plumage mercury than adults. The lowest mean level was noted in juvenile Sooty Terns from the Glorioso Archipelago (0.05 mu g g(-1)). The highest levels were obtained for adult Barau's Petrels from Reunion Island (0.96 mu g g(-1)). An inter-site analysis of Sooty Tern showed higher mercury levels in birds nesting on Juan de Nova Island. Levels were low in comparison... |
Tipo: Text |
Palavras-chave: Tropical islands; Contamination; Bioaccumulation; Mercury; Trophic ecology; Marine birds. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3416.pdf |
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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 |
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Le Bourg, Baptiste. |
Like in the rest of the world, climate change impacts the Southern Ocean, but not in the same way in all regions of this ocean. Changes in sea ice cover around the Antarctic continent are one of the most visible manifestations. For example, sea ice cover has decreased significantly in the Western Antarctic Peninsula while it tends to increase slightly on the rest of the coastline of the continent. These changes in environmental conditions influence the functioning of the ecosystems of this ocean. In particular, the disappearance or persistence of sea ice in a region where it was seasonally present may prevent the appearance of summer phytoplankton blooms, thus impacting the dynamics of krill populations and their predators in the pelagic environment. The... |
Tipo: Text |
Palavras-chave: Sea stars; Southern Ocean; Trophic ecology; Stable isotopes. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00633/74468/74296.pdf |
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Le Croizier, Gael; Schaal, Gauthier; Point, David; Le Loc'H, Francois; Machu, Eric; Fall, Massal; Munaron, Jean-marie; Boye, Aurelien; Walter, Pierre; Lae, Raymond; De Morais, Luis Tito. |
Bioaccumulation of toxic metal elements including mercury (Hg) can be highly variable in marine fish species. Metal concentration is influenced by various species-specific physiological and ecological traits, including individual diet composition and foraging habitat. The impact of trophic ecology and habitat preference on Hg accumulation was analyzed through total Hg concentration and stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) analyses in the muscle of 132 fish belonging to 23 different species from the Senegalese coast (West Africa), where the marine ecosystem is submitted to nutrients inputs from various sources such as upwelling or rivers. Species-specific ecological traits were first investigated and results showed that vertical (i.e.... |
Tipo: Text |
Palavras-chave: Methylmercury sources; Trophic ecology; Feeding habitat; Metal bioaccumulation; Chemical tracers; Isotopic niche. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00458/57013/58912.pdf |
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Rodrigues,Flávio H.G.; Hass,Adriani; Lacerda,Ana C.R.; Grando,Raquel L.S.C.; Bagno,Marcelo A.; Bezerra,Alexandra M.R.; Silva,Wesley R.. |
The maned wolf feeds mainly on fruits and small vertebrates. The diet of maned wolf was studied at Águas Emendadas Ecological Station (AEES) through 328 faecal samples collected from November 1996 to August 1999. To evaluate the seasonal variation in food availability, the fruit phenology of the wolf's fruit, the main food item in maned wolf's diet, was monitored counting the fruits produced in 20 marked plants. Fructification phenology of fleshy fruit plants in the cerrado habitat of AEES was recorded monitoring five plots of 100 x 20 m , where the number of fruit producing species and individuals were recorded. The diet composition was 60% vegetal items and 40% animal ones. The wolf's fruit, other fruits and small mammals were the most frequent consumed... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cerrado domain; Diet composition; Food availability; Trophic ecology. |
Ano: 2007 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-93832007000100005 |
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Dary,Eurizângela P.; Ferreira,Efrem; Zuanon,Jansen; Röpke,Cristhiana P.. |
ABSTRACT This study was carried out in a section of the middle course of the Teles Pires River, a clear water river that drains ancient and highly eroded geological formations, and where five hydropower plants are planned or in construction. In this study we tested the hypothesis that local fish fauna is mainly sustained by autochthonous food resources, with modest changes in the trophic structure of fish assemblages along the hydrometric cycle. Sampling was performed every three months between July 2008 and May 2009 at seven sites distributed along a 50-km section of the river. Piscivores was the most representative group in terms of biomass, abundance and species richness, followed by herbivores, insectivores and omnivores. The trophic structure did not... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Environmental impact; Food resources; Temporal dynamics; Trophic ecology. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000400201 |
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Registros recuperados: 45 | |
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