Wave-generated flow on coral reefs - an analysis for two-dimensional horizontal reef-tops with steep faces

Waves breaking on the seaward rim of a coral reef generate a flow of water from the exposed side of the reef to the sheltered side and/or to either channels through the reef-rim or lower sections of the latter. This wave-generated flow is driven by the water surface gradient resulting from the wave set-up created by the breaking waves. This paper reviews previous approaches to modelling wave-generated flows across coral reefs and discusses the influence of reef morphology and roughness upon these flows. Laboratory measurements upon a two-dimensional horizontal reef platform with a steep reef face provide the basis for extending a previous theoretical analysis for wave set-up on a reef in the absence of a flow [Gourlay, M.R., 1996b. Wave set-up on coral reefs. 2. Set-up on reefs with various profiles. Coastal Engineering 28, 1755] to include the interaction between a unidirectional flow and the wave set-up. The laboratory model results are then used to demonstrate that there are two basic reef-top flow regimes-reef-top control and reef-rim control. Using open channel flow theory, analytical relationships are derived for the reef-top current velocity in terms of the offreef wave conditions, the reef-top water depth and the physical characteristics of the reef-top topography. The wave set-up and wave-generated flow relationships are found to predict experimental values with reasonable accuracy in most cases. The analytical relationships are used to investigate wave-generated flows into a boat harbour channel on Heron Reef in the southern Great Barrier Reef. (c) 2005 Elsevier B.V. All rights reserved

Modelling trophic flows in ecosystems to assess the efficiency of marine protected area (MPA), a case study on the coast of Senegal

Marine protected areas (MPAs) are now viewed as an efficient tool to fight against the global deterioration of habitats and fish populations. However their efficiency and effects on the whole trophic network are little known. Based on the Bolong de Bamboung (Senegal) case study, the objective of this study is to assess the impact of a MPA on the entire trophic network using trophodynamic models. This estuarine small MPA is scientifically surveyed since 2003, one year before the closure of the fishery. Using the resulting dataset, we calculated time series of abundance indices and constructed two Ecopath mass-balanced models for the year 2003 (fished) and the 2006-2008 period (unfished). Using EcoTroph, an ecosystem trophic-level based model, we compared the two periods and simulated a closure of the fishery starting from 2003 to assess the effect of the MPA. We observed a rather constant total biomass, but a biomass increase by a 2.5 factor in predators and a decrease by a 1.7 factor in their preys. Simulations showed that the increase in predators was too important to only being a direct consequence of the removal of the fishing mortality and a local production. This highlighted the role of the MPA as a refuge or a foraging arena for some predator species. What's more, the decrease of the preys, corresponding to pelagic species, was very important and couldn't be explained only by an increase of the predation plus a release of the fishing pressure. This indicated other possible effects as environmental and behavioural ones, in addition of a direct MPA effect. Sensitivity testing and a comparison with another nearby similar but fished area, the Bolong de Sangako, validated the same global conclusion. We concluded that the fishing closure had direct effects but also indirect ones likely due to fish behaviour and environment, and that trophodynamic models are useful tools to analyse MPA effects on the whole trophic network

"Migration or acculturation ? The Saint-Crespin cemetery case (Romilly-sur-Andelle, Eure, France) : confrontation between biologiccal anthropological facts and burial artefacts"

International audienc

Ecopath et EcoTroph : des outils d'évaluation des effets des AMP à l'échelle des réseaux trophiques

International audienceEcopath et EcoTroph : des outils d'évaluation des effets des AMP à l'échelle des réseaux trophique

Who Gets the Catch? How Conventional Catch Attribution Frameworks Undermine Equity in Transboundary Fisheries

The focus on flag States for the purpose of attributing fisheries catch is inconsistent with the assignment of sovereign rights to coastal States under international law and undermines equity in contemporary quota allocation negotiations. We propose modernizing reporting frameworks to include zone-based reporting of fish catches to more equitably present data, ensure consistency with the Law of the Sea, and better support the realization by developing coastal States of their development aspirations consistent with SDG 14, Life Below Water. States are already required to collect the data necessary to support this change, and many regional fisheries management authorities already do so. Reforms to data collection and reporting mechanisms should support zone-based catch attribution as a central feature of negotiations around access to future fishing opportunities on shared resources. Doing so will ensure that the sovereign rights of developing coastal States are properly accounted for and implemented

Energy flow through marine ecosystems: confronting transfer efficiency

Transfer efficiency is a key parameter describing ecosystem structure and function and is used to estimate fisheries production; however, it is also one of the most uncertain parameters.Questions remain about how habitats, food resources, fishing pressure, spatiotemporal scales, as well as temperature, primary production, and other climate drivers impact transfer efficiency.Direct measurements of transfer efficiency are difficult, but observations of marine population abundances, diets, productivity, stable isotope analysis, and models integrating these constraints can provide transfer efficiency estimates.Recent estimates suggest that transfer efficiency is more variable than previously thought, compounding uncertainties in marine ecosystem predictions and projections.Increased understanding of factors contributing to variation in transfer efficiency will improve projections of fishing and climate change impacts on marine ecosystems

Structures and Chemical Equilibria of Some N-Heterocycles Containing Amide Linkages

Structures and chemical equilibria of 5-carboxy-2-thiouracil (1), 5,6-diphenyl-3-hydroxy-1,2,4-triazine (2), 1-phenyl-3-methyl-5-pyrazolone (3) and 2-mercapto-4,6-dimethylpyrimidine hydrochloride (4) are reported. Their electronic transitions are assigned and pK values are evaluated and discussed

Plants and aromatics for embalming in Late Middle Ages and modern period: a synthesis of written sources and archaeobotanical data (France, Italy)

International audienceOccasionally mentioned in written sources since the Early Middle Ages, embalming with evisceration spreads considerably and becomes quite usual practice for aristocratic elites from the late 13th century to the early 19th century. Apothecaries prepare aromatic powders including many plant organs and exudates supposed to preserve the body. Numerous encyclopaedias and treatises of medicine list these ingredients and show that the recipes are very diverse. Moreover, several studies of embalmed bodies have demonstrated the potential of archaeobotanical analyses coupling pollen and macro-remains for identifying this material. This paper aims to compile a synthesis of written and archaeological sources from France and Italy, and to assess the relevance of an interdisciplinary approach for a better understanding of this aristocratic burial practice. It demonstrates that both types of sources and approaches are strongly complementary and highlights their inherent advantages and methodological limitations. In order to understand which criteria were determinant in the composition of the embalming powders, their medicinal, odoriferous and symbolic properties are discussed. Finally, this work proposes some methodological perspectives and triggers new research avenues on the history of pharmacy in Late Medieval and modern Europe