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Food consumption by bathyal decapod crustacean assemblages in the western Mediterranean: predatory impact of megafauna and the food consumption-food supply balance in a deep-water food web Texte intégral
1998
Cartes, Joan Enric | Maynou, Francesc
14 pages, 4 figures, 4 tables | Estimates of the daily ration consumed by decapod assemblages were obtained from 2 continuous sampling cycles conducted over the middle and lower slope (610-710 m and 1178-1240 m depth respectively) of the Catalan Sea (NW Mediterranean). Annual food consumption by decapods decreased from 82.2 mg dry weight (DW) m-2 yr-1 on the middle slope to 20.4 mg DW m-2 yr-1 on the lower slope. Additionally, from literature sources, the food consumption by fishes and the secondary production of macrobenthos and macroplankton were assessed for our deep-sea area. Combining the food consumption of megafauna (decapod crustaceans plus fishes), a model of the food supply-food consumption balance was proposed for the middle slope, the only depth stratum for which adequate information exists. On the middle slope, annual food consumption by megafauna amounted to 160 mg DW m-2 yr-1 while secondary production by the dominant macrobenthic taxa (suprabenthos, epibenthos and infauna) was estimated at 150 mg DW m-2 yr-1. Benthos was the main contributor to the food supply in our megafaunal mid-slope communities. The mean annual contribution of macroplankton was secondary, although it can be seasonally important. Euphausiids were the dominant macroplankton taxon over the middle slope, and only 10.6% of their secondary production (7.3 mg DW m-2 yr-1) was estimated to be consumed by decapods, whereas the total estimated euphausiid production consumed by our mid-bathyal community hardly attained 20%. Our results showed a tight equilibrium between food consumption and food supply on the middle slope. Estimated food consumption by midslope megafauna (0.059 g C m-2 yr-1) is equivalent to calculated values for production by benthic and suprabenthic macrofauna. This value is also consistent with estimates of mid-slope organic carbon through sedimentation (1.8 g C m-2 yr-1), after correcting for metabolism by benthos (from macrofauna to sediment bacteria). These results are consistent with the commonly accepted idea that food is the main limiting factor in deep-sea trophic webs | Peer Reviewed
Afficher plus [+] Moins [-]Observations of the free-swimming behavior of Acartia tonsa: Effects of food concentration and turbulent water motion Texte intégral
1994
Saiz, Enric
13 pages, 5 figures, 7 tables | The free-swimming behavior of the calanoid copepod Acartia tonsa is described as a function of food concentration and quantified turbulence. In still water, Acartia spent most of its time feeding. Time allocated to feeding bouts did not change much as a function of food concentration (from 98% to 81%). Functional response to food was mainly determined by the duration of feeding bouts and the proportion of time spent in them. Lengthy feeding bouts might be involved with the actual capture and ingestion of food, while brief feeding bouts might be involved in the search for an optimum food density and the discrimination of food quality. Turbulence did not affect the amount of time allocated to feeding bouts but induced a significant shift to bouts of shorter duration at low food concentration. Computed encounter rates were 2.5 times higher in the presence of turbulence and indicated that turbulence intensity might have been enough to increase realized food concentrations to levels comparable to satiation at some of the low food concentrations tested
Afficher plus [+] Moins [-]Daily ration estimates and comparative study of food consumption in nine species of deep-water decapod crustaceans of the NW Mediterranean Texte intégral
1998
Maynou, Francesc | Cartes, Joan Enric
11 pages, 3 figures, 3 tables | Estimates of the daily ration consumed by 9 species of decapod crustaceans were obtained from 2 deep-water samplings over the middle and lower continental slope of the NW Mediterranean. The daily rations obtained varied by an order of magnitude from the slow-moving, crab-like species (< 0.1 g dry food per 100 g predator body weight) to the actively swimming mesopelagic shrimps (> 1.0 g dry food per 100 g predator body weight). A multivariate analysis allowed us to relate the variability in daily ration estimates to the functional morphology and ecology of the species considered. The functional morphology and ecology of the species studied are defined in terms of body shape, swimming capability, trophic diversity and spatial distribution. We found that body shape (ratio of carapace length to carapace width) and trophic diversity (H') account for most of the variability in the amount of food consumed by decapods. The food consumption pattern established for our decapod crustaceans is compared to a similar pattern reported for deep-water fishes | Peer Reviewed
Afficher plus [+] Moins [-]Structure and dynamics of food webs along the water column in the western Mediterranean elucidated by stable nitrogen and carbon isotope data Texte intégral
2012
Valls, Maria | Sweeting, C.J. | Quetglas, Antoni | Olivar, M. Pilar | Fernández de Puelles, María Luz | Pasqual, Catalina | Polunin, N.V.C.
Final workshop IDEADOS: The wrapping up of the IDEADOS project, International Workshop on Environment, Ecosystems and Demersal Resources and fisheries, 14-16 November 2012, Palma de Mallorca, Spain | Peer reviewed
Afficher plus [+] Moins [-]The effect of flow speed and food size on the capture efficiency and feeding behaviour of the cold-water coral Lophelia pertusa Texte intégral
2016
Orejas, Covadonga | Gori, Andrea | Rad-Menéndez, Cecilia | Last, Kim S. | Davies, Andrew J. | Beveridge, Christine M. | Sadd, Daniel | Kiriakoulakis, Konstadinos | Witte, Ursula | Roberts, John Murray | European Commission | Natural Environment Research Council (UK)
7 pages, 6 figures, 1 table | The capture efficiency and feeding behaviour of the cold-water coral (CWC) Lophelia pertusa (Linnaeus, 1758) were investigated considering: (1) different food types, (2) different food sizes and (3) different current speeds and temperatures. This study used two different multifactorial experimental approaches: (1) Corals were subjected to three different flow speeds (2, 5 and 10 cm s− 1) in 5 l volume tanks, and three different food types (alive zooplankton, alive algae, and dry particulate organic carbon) were offered to the corals under each current regime, analysing the capture rates of the corals under these different flow velocities. (2) In a flume, the feeding behaviour of the coral polyps was studied under different current speed regimes (1, 7, 15 and 27 cm s− 1) and a temperature change over a range of 8–12 °C. The obtained results confirm that low flow speeds (below 7 cm s− 1) appear optimal for a successful prey capture, and temperature did not have an effect on polyp expansion behaviour for L. pertusa. In conclusion, flow speeds clearly impact food capture efficiency in L. pertusa, with zooplankton predominantly captured prey at low flow velocities (2 cm s− 1) and phytoplankton captured at higher flow velocities of 5 cm s− 1. This split in capture efficiency may allow corals to exploit different food sources under different tidal and flow conditions | This work has been supported by the European Commission through two ASSEMBLE projects (grant agreement no. 227799) conducted in 2010 and 2011 at SAMS, as well as by the UK Ocean Acidification Research Programme's Benthic Consortium project (awards NE/H01747X/1 and NE/H017305/1) funded by NERC | Peer Reviewed
Afficher plus [+] Moins [-]Phosphorus budget in the water-agro-food system at nested scales in two contrasted regions of the world (ASEAN-8 and EU-27) Texte intégral
2015
Garnier, Josette | Romero, Estela | Dorioz, Jean-Marcel | Région Ile-de-France | Fundación Iberdrola
Garnier, Josette ... et. al.-- 21 pages, 5 figures, 2 tables | Phosphorus (P) plays a strategic role in agricultural production as well as in the occurrence of freshwater and marine eutrophication episodes throughout the world. Moreover, the scarcity and uneven distribution of minable P resources is raising concerns about the sustainability of long-term exploitation. In this paper we analyze the P cycle in anthropic systems with an original multiscale approach (world region, country, and large basin scales) in two contrasting world regions representative of different trajectories in socioeconomic development for the 1961–2009 period: Europe (EU-27)/France and the Seine River Basin, and Asia (ASEAN-8)/Vietnam and the Red River Basin. Our approach highlights different trends in the agricultural and food production systems of the two regions. Whereas crop production increased until the 1980s in Europe and France and has stabilized thereafter, in ASEAN-8 and Vietnam it began to increase in the 1980s and it is still rising today. These trends are related to the increasing use of fertilizers, although in European countries the amount of fertilizers sharply decreased after the 1980s. On average, the total P delivered from rivers to the sea is 3 times higher for ASEAN-8 (300 kg P km−2 yr−1) than for EU-27 countries (100 kg P km−2 yr−1) and is twice as high in the Red River (200 kg P km−2 yr−1) than in the Seine River (110 kg P km−2 yr−1), with agricultural losses to water in ASEAN-8 3 times higher than in EU-27. Based on the P flux budgets, this study discusses early warnings and management options according to the particularities of the two world regions, newly integrating the perspective of surface water quality with agricultural issues (fertilizers, crop production, and surplus), food/feed exchanges, and diet, defining the so-called water-agro-food system | The FIRE-FR3020 research federation is gratefully acknowledged for the organization of an interdisciplinary workshop during which the paper emerged. Estela Romero was funded by a Research Fellowship from the Iberdrola Foundation, and Najla Aissa-Grouz and Lauriane Vilmin were granted by a R2DS-Ile-de-France Region scholarship | Peer Reviewed
Afficher plus [+] Moins [-]Non-proportional bioaccumulation of trace metals and metalloids in the planktonic food web of two Singapore coastal marine inlets with contrasting water residence times Texte intégral
2016
Calbet, Albert | Schmoker, Claire | Russo, Francesca | Trottet, Aurore | Mahjoub, Mohamed-Sofiane | Larsen, Ole | Tong, Hor Yee | Drillet, Guillaume | National Parks Board (Singapore) | Nanyang Technological University | Danish Council for Independent Research | Ministerio de Economía y Competitividad (España)
11 pages, 5 figures, 5 tables, 1 appendix supplementary data https://dx.doi.org/10.1016/j.scitotenv.2016.03.234.-- This work is a contribution to the consolidated research group 2014 SGR 498 of the Generalitat de Catalunya | We analyzed the concentrations of trace metals/metalloids (TMs) in the water, sediment and plankton of two semi-enclosed marine coastal inlets located north of Jurong Island and separated by a causeway (SW Singapore; May 2012-April 2013). The west side of the causeway (west station) has residence times of approximately one year, and the east side of the causeway (east station) has residence times of one month. The concentrations of most of the TMs in water and sediment were higher in the west than in the east station. In the water column, most of the TMs were homogeneously distributed or had higher concentrations at the surface. Preliminary evidence suggests that the TMs are primarily derived from aerosol depositions from oil combustion and industry. Analyses of TMs in seston (>. 0.7 μm; mostly phytoplankton) and zooplankton (>. 100 μm) revealed that the seston from the west station had higher concentrations of most TMs; however, the concentrations of TMs in zooplankton were similar at the two stations. Despite the high levels of TMs in water, sediment and seston, the bioaccumulation detected in zooplankton was moderate, suggesting either the presence of effective detoxification mechanisms or/and the inefficient transfer of TMs from primary producers to higher trophic levels as a result of the complexity of marine planktonic food webs. In summary, the TM concentrations in water and seston are not reliable indicators of the bioaccumulation at higher trophic levels of the food web | This work was funded through grant MadeInPlankton from Singapore National Parks Board - Singapore (NParks) and DHI-NTU Research Centre and Education Hub, Ung EliteForsk grants 10-093759 and 10-094773 from the Danish Ministry for Independent Research to GD, and Projects PROTOS (CTM2009-08783), TOPCOP (CTM2011-23480) and FERMI (CGL2014-59227-R) from the Spanish Ministry of Economy and Competitiveness to AC | Peer Reviewed
Afficher plus [+] Moins [-]Trophic relationships in deep-water decapods of Le Danois bank (Cantabrian Sea, NE Atlantic): Trends related with depth and seasonal changes in food quality and availability Texte intégral
2007
Cartes, Joan Enric | Huguet, Carme | Parra, Santiago | Sánchez, Francisco
20 pages, 8 figures, 5 tables | The trophic relationships of decapod crustaceans on Le Danois bank (NE of Iberian Peninsula, NE Atlantic Ocean) were studied within the framework of the multidisciplinary project ECOMARG during two surveys, one in October 2003 and the other in April 2004. The diets of eleven species of decapods were analyzed and, within a rather continuous gradient of food source exploitation, 3 trophic groups were identified: (1) plankton feeders, comprising the shrimps Acanthephyra pelagica, Sergia robusta, and Pasiphaea tarda, which preyed on meso-bathypelagic taxa such as euphausiids and calanoids; (2) benthos feeders, comprising the crangonids Pontophilus norvegicus and Pontophilus spinosus, the crab Geryon trispinosus and the shrimp Aristeus antennatus; and (3) an intermediate group, including the rest of species, with mixed diets that included detritus. Among the third group, anomurans (Munida tenuimana, Pagurus alatus, and Parapagurus pilosimanus) consumed phytoplanktonic detritus in April, suggesting a link with peaks of surface Chl a occurring between March and April in the study area. Gut pigment and isotopic (δ13C/δ15N correlations) analyses revealed that assemblages inhabiting the top of the bank (455–612 m) and the inner basin (642–1048 m, close to the Lastres canyon head) had different food sources, with species inhabiting the deepest region exhibiting a stronger dependence on marine snow derivatives. These results are consistent with the higher proportion of mud and sediment organic matter (OM) content in the inner basin (82.2% pellites; 6.3% OM at 1028 m) compared to the top of the Le Danois bank (only 13.9% pellites; 2.8% OM at 485 m), which is a hydrodynamically more active zone. Exploitation of different food sources is also consistent with differences in the trophic level of species, inferred from stable δ15N isotope analyses, which yield values ranging from 6.88‰ for the hermit crab P. alatus to 13.52‰ for the crangonid shrimp P. norvegicus. Stomach fullness was higher in April 2004 than in October 2003, both between and within species of the dominant decapods, including detritus feeders (M. tenuimana) and benthos feeders (e.g. G. trispinosus, P. norvegicus). Most species exhibited a parallel increase in their density in April 2004, with a significant positive correlation between density and stomach fullness. This increase coincides with a peak of surface Chl a concentration occurring in March–April | Pigment analyses were performed thanks to NOW-ALW (Project No. 152911) | Peer reviewed
Afficher plus [+] Moins [-]La temperatura del agua y la alimentación, claves para entender la distribución de la merluza en el Mediterráneo | Un nuevo modelo predecirá dónde hay merluza a través de la temperatura | Biologos marinos crean un modelo que predice donde están los bancos de merluzas Texte intégral
2020
Lloret Lloret, Elena
Una combinación de factores ambientales y bióticos, es decir la información sobre la temperatura del agua y la localización de las especies de la que se alimentan, es la clave del nuevo modelo de distribución de la merluza europea (Merluccius merluccius) que han desarrollado un grupo de investigadores del Institut de Ciències del Mar (ICM-CSIC) y del Centro Oceanográfico de Vigo del Instituto Español de Oceanografía (IEO). Se trata de una herramienta de enorme potencial, ya que la merluza europea es una de las especies más pescadas en el Mediterráneo, donde tiene un gran valor comercial. Por eso este nuevo modelo de predicción de la distribución podría ayudar a “asegurar la sostenibilidad de los stocks”. Para ello, indica el IEO, es “importante conocer su distribución espacial, su ecológica trófica y la manera en la que interacciona con el medio”. [...] | Peer reviewed
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