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Understanding spatial and temporal dynamics of non-algal particles in open ocean is of the utmost importance to improve estimations of carbon export and sequestration. These particles covary with phytoplankton abundance but also accumulate independently of algal dynamics. The latter likely represents an important fraction of organic carbon, but it is largely overlooked. A possible way to study these particles is via their optical backscattering properties (bbp) and relationship with chlorophyll-a (Chl). To this aim, we estimate the fraction of bbp associated with the non-algal particle portion ((Formula presented.)) that does not covary with Chl by using a global Biogeochemical-Argo data set. We quantify the spatial, temporal, and vertical variability of (Formula presented.). In the northern productive areas, (Formula presented.) is a small fraction of bbp and shows a clear seasonal cycle. In the Southern Ocean, bkbp is a major fraction of total bbp. In oligotrophic areas, (Formula presented.) has a smooth annual cycle.

The South Brazilian Bight (SBB) is a hydrographically dynamic environment with strong seasonality that sustains a diverse planktonic community involved in diverse biogeochemical processes. The inherent optical properties (IOPs; e.g., absorption and scattering coefficients) of optically actives constituents of water (OACs; phytoplankton, non-algal particles–NAP, and colored dissolved organic matter–CDOM) have been widely employed to retrieve information on biogeochemical parameters in the water. In this study conducted in the SBB, a cross-shelf transect was performed for biogeochemistry and hydrographic sampling during a summer expedition. Our research aimed to determine the distribution and amount of the optically active constituents of water based on their spectral signature, in relation to the distribution of water masses in the region. That allows us to get insights into the biogeochemical processes within each water mass and in the boundaries between them. We observed a strong intrusion of South Atlantic Central Water (SACW) over the shelf, mainly driven by the wind action. With that, phytoplankton development was fueled by the input of nutrients, and increased chlorophyll-a (Chl-a) concentrations were observed within the shallowest stations. Colored dissolved organic matter (CDOM) did not follow the distribution of dissolved organic carbon (DOC). Both CDOM and DOC presented high values at the low salinity Coastal Water (CW), as an indication of the continental influence over the shelf. However, CDOM was inversely correlated with salinity and lowest values were observed within Tropical Water (TW), whereas DOC values within TW were as high as within CW, indicating an autochthonous DOM source. Additionally, a deep Chl-a maximum (DCM) was noticed in the boundary between the TW and SACW. Along with the DCM, we observed the production of fresh, non-colored DOM attributed to the microbial community. Finally, our results suggest that CDOM is photodegraded at the surface of CW. This is mainly due to the Ekman transport effect over the region that traps CW at the surface, making it longer exposed to solar radiation.

La présente contribution s’interroge sur le régime juridique international des éléments territoriaux naturels mobiles (comme des espèces vivantes et des ressources aquatiques) dans le contexte du changement climatique. Dans un premier temps, ces éléments sont déterminés par rapport aux théories juridiques sur le territoire étatique. Même si le droit international traditionnel éprouve des difficultés conceptuelles face à cette mobilité, il est effectivement possible de rassembler ces éléments dans une catégorie juridique homogène. Cela permet, dans un second temps, de proposer les principes applicables à ces éléments, à la fois sur le plan procédural et matériel., This paper is looking for a comprehensive international legal regime applying to mobile natural elements of territory (such as living species and water resources) in the context of climate change. In a first step, these elements have to be defined in relation to the existing legal theories on state territory. Even if there are some conceptual difficulties to face mobility of natural elements following a traditional international law approach, it is indeed possible to gather them into a homogenous legal category. This allows, in a second step, to establish procedural and substantive principles applicable for these elements in international law.

The late stage of the North East Atlantic (NEA) spring bloom was investigated during June 2005 along a transect section from 45 to 66° N between 15 and 20° W in order to characterize the contribution of siliceous and calcareous phytoplankton groups and describe their distribution in relation to environmental factors. We measured several biogeochemical parameters such as nutrients, surface trace metals, algal pigments, biogenic silica (BSi), particulate inorganic carbon (PIC) or calcium carbonate, particulate organic carbon, nitrogen and phosphorus (POC, PON and POP, respectively), as well as transparent exopolymer particles (TEP). Results were compared with other studies undertaken in this area since the JGOFS NABE program. Characteristics of the spring bloom generally agreed well with the accepted scenario for the development of the autotrophic community. The NEA seasonal diatom bloom was in the late stages when we sampled the area and diatoms were constrained to the northern part of our transect, over the Icelandic Basin (IB) and Icelandic Shelf (IS). Coccolithophores dominated the phytoplankton community, with a large distribution over the Rockall-Hatton Plateau (RHP) and IB. The Porcupine Abyssal Plain (PAP) region at the southern end of our transect was the region with the lowest biomass, as demonstrated by very low chl-a concentrations and a community dominated by picophytoplankton. Early depletion of dissolved silicic acid (DSi) and increased stratification of the surface layer most likely triggered the end of the diatom bloom, leading to coccolithophore dominance. The chronic Si deficiency observed in the NEA could be linked to moderate Fe limitation, which increases the efficiency of the Si pump. TEP closely mirrored the distribution of both biogenic silica at depth and prymnesiophytes in the surface layer suggesting the sedimentation of the diatom bloom in the form of aggregates, but the relative contribution of diatoms and coccolithophores to carbon export in this area still needs to be resolved.

Se evaluó el patrón de distribución espacial así como la contribución de las fracciones del plancton a la biomasa planctónica menor de 200 μm en la región NW de las aguas oceánicas adyacentes a Cuba en muestreos realizados en época de invierno (febrero de 1997 y marzo 1999). Los valores de la biomasa bacteriana variaron entre 1.6 y 11.4 mgC m-3, del nanoplancton entre 5.2 y 20.8 mgC m-3 (Xmedia = 11.4 ± 5.4 mgC m-3) y la del microzooplancton entre 4.2 y 15.5 mgC m-3 (Xmedia = 7.9 ± 3.2 mgC m-3). El microfitoplancton presentó valores de biomasa que variaron entre 1.95 y 15.7 mgC m-3 (Xmedia = 8.8 ± 3.7 mgC m-3). Los mayores valores de biomasa de todas las fracciones estudiadas se encontraron en las aguas oceánicas adyacentes a la zona entre las bahías de Mariel y La Habana. El nanoplancton fue la fracción que más aportó a la biomasa menor de 200 μm en la capa fótica, seguida del microzooplancton, tanto en la estación con influencia costera (N.57) como en la oceánica (N.18). Published Aguas oceánicas, Microzooplancton, Microfitoplancton

The Cambodia environment monitor 2008 is one of a series of environmental reports prepared for East Asian countries under an initiative sponsored by the World Bank. The objective of this series is to present a snapshot of environmental trends across a range of issues. The purpose of the monitor is to engage and inform interested stakeholders about key environmental changes in an easy to understand format accessible to a wide audience. This report identifies seven strategic priorities for the Royal government of Cambodia and its conservation partners. 1)articulate a clear and shared vision and re-commitment to conservation goals and objectives; 2)formalize a meaningful enabling legal and regulatory framework for management and protection of conservation areas; 3)formulate clear strategies for recognizing and improving community benefit sharing in conservation areas; 4) strengthen mechanisms for institutional coordination across the ministries; 5) adopt new approaches and paradigms for conservation areas management; 6) with donors, develop and secure sustainable sources of funding for conservation; and 7) reinforce the human resource capacity to implement and manage conservation areas.

We measured the vertical and seasonal distribution of picoplankton (0.2–2 μm) and nanoplankton (2–20 μm) in the photic layer of Cuban southern oceanic and coastal waters. The concentration of the different fractions was estimated by epifluorescence microscopy. Heterotrophic components from the different fractions showed higher vertical stratification in the oceanic station in comparison to the coastal one. The autotrophic components showed an irregular vertical distribution pattern, both in coastal and oceanic stations. In all the analyzed stations, the heterotrophic bacteria showed an inverse correlation with the autotrophic (r= -0.98), and the heterotrophic nanoplankton (r= -0.96). Auto and heterotrophic nanoplankton probably regulate bacteria abundance by predation, although autotrophic nanoplankton may represent a source of organic matter for microorganisms. Determinamos la distribución vertical y estacional del picoplancton (0.2–2 μm) y el nanoplancton (2–20 μm) en la capa fótica de las aguas oceánicas y costeras al sur de Cuba. La concentración de las diferentes fracciones fue estimada mediante microscopía de epifluorescencia. Los componentes heterotróficos de las diferentes fracciones mostraron una elevada estratificación vertical en la estación oceánica en comparación con la estación costera. Por otro lado, los componentes autotróficos presentaron un patrón de distribución vertical irregular tanto en la estación costera como en la oceánica. En los análisis realizados las bacterias heterótrofas mostraron una correlación inversa con el nanoplancton autótrofo (r= -0.98), y con el nanoplancton heterótrofo (r= -0.96). Estos resultados sugieren que el nanoplancton (autótrofo y heterótrofo) probablemente regula la abundancia de bacterias mediante la depredación, además que el nanoplancton autótrofo pudiera representar una fuente de materia orgánica para losmicroorganismos.

We measured the vertical and seasonal distribution of picoplankton (0.2-2 µm) and nanoplankton (2-20 µm) in the photic layer of Cuban southern oceanic and coastal waters. The concentration of the different fractions was estimated by epifluorescence microscopy. Heterotrophic components from the different fractions showed higher vertical stratification in the oceanic station in comparison to the coastal one. The autotrophic components showed an irregular vertical distribution pattern, both in coastal and oceanic stations. In all the analyzed stations, the heterotrophic bacteria showed an inverse correlation with the autotrophic (r= -0.98), and the heterotrophic nanoplankton (r= -0.96). Auto and heterotrophic nanoplankton probably regulate bacteria abundance by predation, although autotrophic nanoplankton may represent a source of organic matter for microorganisms. Rev. Biol. Trop. 55 (2): 449-457. Epub 2007 June, 29.Determinamos la distribución vertical y estacional del picoplancton (0.2-2 µm) y el nanoplancton (2-20 µm) en la capa fótica de las aguas oceánicas y costeras al sur de Cuba. La concentración de las diferentes fracciones fue estimada mediante microscopía de epifluorescencia. Los componentes heterotróficos de las diferentes fracciones mostraron una elevada estratificación vertical en la estación oceánica en comparación con la estación costera. Por otro lado, los componentes autotróficos presentaron un patrón de distribución vertical irregular tanto en la estación costera como en la oceánica. En los análisis realizados las bacterias heterótrofas mostraron una correlación inversa con el nanoplancton autótrofo (r= -0.98), y con el nanoplancton heterótrofo (r= -0.96). Estos resultados sugieren que el nanoplancton (autótrofo y heterótrofo) probablemente regula la abundancia de bacterias mediante la depredación, además que el nanoplancton autótrofo pudiera representar una fuente de materia orgánica para los microorganismos.