Assessment of coastal management options by means of multilayered ecosystem models

This paper presents a multilayered ecosystem modelling approach that combines the simulation of the biogeochemistry of a coastal ecosystem with the simulation of the main forcing functions, such as catchment loading and aquaculture activities. This approach was developed as a tool for sustainable management of coastal ecosystems. A key feature is to simulate management scenarios that account for changes in multiple uses and enable assessment of cumulative impacts of coastal activities. The model was applied to a coastal zone in China with large aquaculture production and multiple catchment uses, and where management efforts to improve water quality are under way. Development scenarios designed in conjunction with local managers and aquaculture producers include the reduction of fish cages and treatment of wastewater. Despite the reduction in nutrient loading simulated in three different scenarios, inorganic nutrient concentrations in the bay were predicted to exceed the thresholds for poor quality defined by Chinese seawater quality legislation. For all scenarios there is still a Moderate High to High nutrient loading from the catchment, so further reductions might be enacted, together with additional decreases in fish cage culture. The model predicts that overall, shellfish production decreases by 10%–28% using any of these development scenarios, principally because shellfish growth is being sustained by the substances to be reduced for improvement of water quality. The model outcomes indicate that this may be counteracted by zoning of shellfish aquaculture at the ecosystem level in order to optimize trade-offs between productivity and environmental effects. The present case study exemplifies the value of multilayered ecosystem modelling as a tool for Integrated Coastal Zone Management and for the adoption of ecosystem approaches for marine resource management. This modelling approach can be applied worldwide, and may be particularly useful for the application of coastal management regulation, for instance in the implementation of the European Marine Strategy Framework Directive

PHOTOMETRIC VARIABILITY IN THE HR-DIAGRAM L. Eyer, M. Grenon

The Hipparcos satellite has detected systematically variable stars when the amplitudes exceed a magnitude dependent threshold, as small as a few millimag for bright stars. The published data about variable stars result from the work of two groups at the Geneva Observatory and at the Royal Greenwich Observatory. It contains information about periodic variables (extrema, periods and epochs) and about `unsolved' variables (amplitudes). Here, a more general description of the HR-diagram is made in terms of stability, microvariability, variability, and variation time scales. A particular emphasis is put on the limits of stability areas and their signification. Key words: Variable Stars, photometry, Hipparcos. 1. INTRODUCTION Hipparcos furnished more than 13 million photometric measurements for 118 204 stars, that is a mean of 110 Hp magnitudes per star over a time span of 3.3 years. However the number of these measurements may vary strongly from one star to an other as well as the time samp..

VOLUME 13: THE ATLAS OF IDENTIFICATION CHARTS D. M'egevand, P. Bartholdi, L. Weber

The process of editing a large atlas of charts is presented. The different steps include the extraction processes of the interesting information out of the GSC and DSS CD-ROMs, the elimination of noise, the technical aspects to produce the different charts (Parts D and G) and the difficulties linked to the number and the size of the files produced. Key words: star charts; L A T E X. 1. INTRODUCTION A significant number of the stars measured by the Hipparcos satellite are uneasy to identify. They represent one tenth of the sample of about 120 thousand stars. To ensure a correct identification and to help people making additional measurements of these stars, an atlas of identification charts has been prepared. The original idea (M'egevand 1991), used for the Hipparcos Input Catalogue Annex 2 (Grenon et al. 1992) was to prepare the charts with the Guide Star Catalog `GSC' (Lasker et al. 1990). In some situations however, it was impossible to get a correct chart from the GSC, the field ..

Michel Mayor, Didier Queloz, St'ephane Udry

: The burst of discoveries of planets and brown dwarfs during the past year has revealed an unexpected diversity of planetary systems. 51 Pegasi, the first extrasolar planet detected in orbit around a solar--type star appears to be the prototype of a new family of Jovian planets, the "Hot Jupiters". Though the physical mechanisms underlying the orbital decay of protoplanets are already understood, we are far from having a general view of planetary formation and of the diversity of planetary systems. If the orbital decay of protoplanets is sometimes so efficient, what is the frequency of planetary systems like ours, what is the frequency of telluric planets, what is the limit between planets and brown dwarfs? 1) 51 Pegasi, the first extrasolar planet: prototype of "Hot Jupiter"--type planets Didier Queloz and myself (MM) have started rather recently in the existing domain of extrasolar research, in April 1994. We entered the club of planet hunters quite late compared to the already "ac..

Individual stars in Fornax dSph center

VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'A high-resolution VLT/FLAMES study of individual stars in the centre of the Fornax dwarf spheroidal galaxy.' (bibcode: 2010A&A...523A..17L

Gamow-Teller beta decay of even-even nuclei close to the doubly magic nucleus "1"0"0Sn

Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman