1,738 publications from this institution
Data on blomass vanablllty and productlon/biomass ratlos of seagrass communltles were analysed to descrlbe the relationship between the trophic (I e pnmary production) and structural (I e b~omass) roles of manne submerged macrophytes The analyses revealed that most ( > 7 0 % ) of the b~omass varlablllty appears to reflect seasonal responses and that the extent of varlabllity IS constrained by the latltudlnal posltlon of the plant stands, those at lower latltudes sustaining a more unlform blomass throughout the year Annual product~on/biomass ratlos are qulte varlable although tend to be greater (average = 4 6) than those for freshwate~ submerged plants, and tend to lncrease at lower latltudes Thls trend IS not attributable to greater dally product~on/b~omass r a t ~o s for troplcal and subtropical communities but appears to be a consequence of thelr small blomass seasonallty
Plastic pollution has become one of the most pressing environmental challenges and has received commensurate widespread attention. Although it is a top priority for policymakers and scientists alike, the knowledge required to guide decisions, implement mitigation actions, and assess their outcomes remains inadequate. We argue that an integrated, global monitoring system for plastic pollution is needed to provide comprehensive, harmonized data for environmental, societal, and economic assessments. The initial focus on marine ecosystems has been expanded here to include atmospheric transport and terrestrial and freshwater ecosystems. An earth-system-level plastic observation system is proposed as a hub for collecting and assessing the scale and impacts of plastic pollution across a wide array of particle sizes and ecosystems including air, land, water, and biota and to monitor progress toward ameliorating this problem. The proposed observation system strives to integrate new information and to identify pollution hotspots (i.e., production facilities, cities, roads, ports, etc.) and expands monitoring from marine environments to encompass all ecosystem types. Eventually, such a system will deliver knowledge to support public policy and corporate contributions to the relevant United Nations (UN) Sustainable Development Goals (SDGs).
Integrated Marine Biogeochemistry and Ecosystem Research Open Science Conference (IMBER OSC 2014), Future Oceans, Research for marine sustainability: multiple stressors, drivers, challenges and solutions, 23-27 June 2014, Bergen, Norway
Datos tecnicos: 4 minutos, color, espanol e ingles con subtitulos en espanol. Ficha tecnica: Gabinete de Presidencia CSIC y Departamento de Comunicacion
Abstract. Diatoms are generally the dominant contributors to the Arctic Ocean spring bloom, which is a key event in regional food webs in terms of capacity for secondary production and organic matter export. Dissolved silicic acid is an obligate nutrient for diatoms and has been declining in the European Arctic since the early 1990s. The lack of regional silicon cycling information precludes understanding the consequences of such changes for diatom productivity during the Arctic spring bloom. This study communicates the results from a cruise in the European Arctic around Svalbard, which reports the first concurrent data on biogenic silica production and export, export of diatom cells, the degree of kinetic limitation by ambient silicic acid, and diatom contribution to primary production. Regional biogenic silica production rates were significantly lower than those achievable in the Southern Ocean and silicic acid concentration limited the biogenic silica production rate in 95 % of samples. Compared to diatoms in the Atlantic subtropical gyre, regional diatoms are less adapted for silicic acid uptake at low concentration, and at some stations during the present study, silicon kinetic limitation may have been intense enough to limit diatom growth. Thus, silicic acid can play a critical role in diatom spring bloom dynamics. The diatom contribution to primary production was variable, ranging from <10 % to ∼100 % depending on the bloom stage and phytoplankton composition. While there was agreement with previous studies regarding the export rate of diatom cells, we observed significantly elevated biogenic silica export. Such a discrepancy can be resolved if a higher fraction of the diatom material exported during our study was modified by zooplankton grazers. This study provides the most direct evidence to date suggesting the important coupling of the silicon and carbon cycles during the spring bloom in the European Arctic.
Los procesos de movilización y protesta han experimentado una innegable transformación en los últimos años. A partir de la ya clásica definición de “nuevos movimientos sociales” esbozada por Alain Touraine en los años ochenta, o la de “movimientos populares” de Leopoldo Múnera en los noventa, la discusión posteriormente se transformó desde orillas diferentes bajo el paradigma interseccional y la teoría crítica. En la actualidad, una cuarta generación de formas de movilización (4.0), ha venido emergiendo en el marco de profundos procesos de individualización social, universalización de las redes sociales, precarización y aumento de las brechas de desigualdad.
 Estas formas de organización colectiva son profundamente horizontales, tienen dificultades, o no reconocen totalmente los mecanismos de representación tradicional de la izquierda. Se movilizan a modo de enjambre, como esboza Byung-Chul Han, e invitan a repensar o deconstruir la fácil conceptualización oficial del “vándalo”. Asimismo, plantean la necesidad de pensar espacios de diálogo social multinivel y multisituados.
 A esta nueva forma de interpelación y organización social la hemos sintetizado, para esta convocatoria, bajo la categoría temporal de Paros 4.0. Dicha invitación fue acogida por varios grupos e individuos, que buscan aportar a pensar estos nuevos fenómenos sociales que seguramente seguirán profundizándose como lineamientos de la acción colectiva organizada.
 Como podrá observarse en los articulos que hacen parte del presente número, los principales actores de las protestas representaban los sectores víctimas de la desigualdad y de la exclusión histórica en Colombia. Jóvenes desempleados o sin acceso a la educación, trabajadores informales, colectivos étnicos y culturales, desplazados, víctimas del conflicto, personas vinculadas con trabajos ilícitos, actores armados en proceso de reincorperación, entre otros, hicieron un llamado a ser tenidos en cuenta tanto por sus semejantes, como por las instituciones del poder.
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 374:75-84 (2009) - DOI: https://doi.org/10.3354/meps07715 Dissolved organic matter release in a Posidonia oceanica meadow Cristina Barrón1,2,*, Carlos M. Duarte1 1IMEDEA (CSIC-UIB), C/ Miquel Marqués 21, 07190 Esporles (Islas Baleares), Spain 2Present address: Vrije Universiteit Brussel, Analytical and Environmental Chemistry, Pleinlaan 2, 1050 Brussels, Belgium *Email: cbarron@vub.ac.be ABSTRACT: We examined annual nutrient changes (nitrate, phosphate and ammonium) and the net dissolved organic carbon (DOC), nitrogen (DON) and phosphorus (DOP) release using in situ benthic incubations in a Posidonia oceanica meadow and in unvegetated sediments of Magalluf Bay (Mallorca Island, Spain) at monthly intervals. We also examined the role of the P. oceanica meadow in the C:N:P ratio transformations by comparing the ratios between the inorganic and dissolved organic fluxes in the seagrass ecosystem and those in the plant material. Our results indicate that P. oceanica communities enhance DOC fluxes relative to adjacent unvegetated sediments. The net DOC release from the P. oceanica meadow represents 71% of the net community production. The C:N:P ratio in the flux of dissolved organic material (DOM) from the P. oceanica community (1450:69:1) exceeded the C:N:P ratio in the DOM flux of unvegetated sediment communities. The high flux of DOC release from this seagrass community might be enriched in carbon compounds, as these plants produce non-structural carbohydrates in excess. KEY WORDS: Benthic fluxes · Seagrasses · Dissolved organic carbon · Posidonia oceanica · Dissolved organic matter · Carbohydrates Full text in pdf format PreviousNextCite this article as: Barrón C, Duarte CM (2009) Dissolved organic matter release in a Posidonia oceanica meadow. Mar Ecol Prog Ser 374:75-84. https://doi.org/10.3354/meps07715 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 374. Online publication date: January 13, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.
