24 research outputs found
Distribution maps of cetacean and seabird populations in the North‐East Atlantic
1. Distribution maps of cetaceans and seabirds at basin and monthly scales are needed for conservation and marine management. These are usually created from standardized and systematic aerial and vessel surveys, with recorded animal den- sities interpolated across study areas. However, distribution maps at basin and monthly scales have previously not been possible because individual surveys have restricted spatial and temporal coverage.
2. This study develops an alternative approach consisting of: (a) collating diverse survey data to maximize spatial and temporal coverage, (b) using detection func- tions to estimate variation in the surface area covered (km2) among these surveys, standardizing measurements of effort and animal densities, and (c) developing species distribution models (SDM) that overcome issues with heterogeneous and uneven coverage.
3. 2.68 million km of survey data in the North-East Atlantic between 1980 and 2018 were collated and standardized. SDM using Generalized Linear Models and General Estimating Equations in a hurdle approach were developed. Distribution maps were then created for 12 cetacean and 12 seabird species at 10 km and monthly resolution. Qualitative and quantitative assessment indicated good model performance.
4. Synthesis and applications. This study provides the largest ever collation and standardization of diverse survey data for cetaceans and seabirds, and the most comprehensive distribution maps of these taxa in the North-East Atlantic. These distribution maps have numerous applications including the identification of im- portant areas needing protection, and the quantification of overlap between vul- nerable species and anthropogenic activities. This study demonstrates how the analysis of existing and diverse survey data can meet conservation and marine management needs.Versión del editor4,7
Optimising the future Belgian offshore wind farm monitoring programme
Six years of monitoring triggered a reflection on how to best continue with the monitoring programme. The basic monitoring has to be rationalised at the level of the likelihood of impact detection, the meaningfulness of impact size and representativeness of the findings. Targeted monitoring should continue to disentangle processes behind the observed impact, for instance the overarching artificial reef effect created by wind farms. The major challenge however remains to achieve a reliable assessment of the cumulative impacts. Continuing consultation and collaboration within the Belgian offshore wind farm monitoring team and with foreign marine scientists and managers will ensure an optimisation of the future monitoring programme
Novel concepts for preparation of reference materials as whole water samples for priority substances at nanogram-per-liter level using model suspended particulate matter and humic acids
Screening tests for hazard classification of complex waste materials : selection of methods
Caramel colour and process contaminants in foods and beverages, part II : occurrence data and exposure assessment of 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) and 4-methylimidazole (4-MEI) in Belgium
In Europe, 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) and 4-methylimidazole (4-MEI) are - to a certain level - allowed to be present in the food colours ammonia caramel (E 150c) and sulphite ammonia caramel (E 150d). Besides their presence in food colours, exposure to these contaminants may also include other dietary sources. This study describes the occurrence of THI and 4-MEI in a wide variety of food products (n = 522) purchased from the Belgian market and their dietary intake in Belgian consumers from 15 years old onwards. THI was found to be present in 22.4% of the investigated foods at a level up to 551 mu g/kg. For 4-MEI (57.7% quantifiable), concentrations up to 2,835 mu g/kg were observed. The average dietary intake amounted to 0.02-0.36 mu g kg(-1) bw(-1) day for THI and 0.4-3.7 mu g kg(-1) bw(-1) day for 4-MEI. Coffee, cola and beer were contributing most to the dietary THI and 4-MEI intake in Belgium
Resolving the unresolved complex mixture in motor oils using high-performance liquid chromatography followed by comprehensive two-dimensional gas chromatography
DISCRISET : a battery of tests for fast waste classification : application of tests on waste extracts
Caramel colour and process by-products in foods and beverages, part I : development of a UPLC-MS/MS isotope dilution method for determination of 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)imidazole (THI), 4-methylimidazole (4-MEI) and 2-methylimidazol (2-MEI)
Caramel colours are used by the food industry in a wide range of foods and beverages. During their manufacturing, low molecular weight compounds such as 4-methylimidazole (4-MEI), the structural isomer of 4-MEI, 2-methylimidazole (2-MEI) and 2-acetyl-4-tetrahydroxy-butylimidazole (THI) are generated. The presence of these inevitable by-products of caramel manufacturing can be hazardous to human health. This publication describes an isotope dilution Ultra-High-performance Liquid Chromatography tandem mass spectrometric method (UHPLC-MS/MS) that was developed and validated for the simultaneous quantification of these impurities in both beverages/liquids and foods. A limit of quantification of 5 mu g/kg was obtained for 4-MEI and THI. The expanded measurement uncertainty (U; k = 2) for these compounds was below 51% in beverages/liquids and below 56% in foods. As higher measurement uncertainties were obtained for 2-MEI, the developed analytical procedure can only be used in a semi-quantitative way for this compound