Qualifying and quantifying offshore wind farm-generated noise

The construction, operation and dismantling of offshore wind farms generate noise both above and under water that may be of environmental concern. The maximum detected sound power level of the above water pin piling noise for example, reached 145 dB(A), while the operational sound power level amounted to 105-115 dB(A) at high wind speed. Underwater construction noise was close to ambient noise levels for gravity based foundations (about 115 dB re 1 µPa RMS), while pin piling and especially monopile piling produced excessive levels of underwater noise up to 194 dB re 1 µPa (zero to peak level at 750m), attenuating to ambient noise levels at a distance of up to 70 km. Whether or not such noise levels are to be considered acceptable will depend on the future implementation of proposed regulations into the Belgian legislation

Vascular reactivity is altered in the placentas of fetuses with congenital diaphragmatic hernia

Introduction: Infants with congenital diaphragmatic hernia (CDH) often develop pulmonary hypertension but frequently fail to respond to vasodilator therapy, for instance because of an altered pulmonary vasoreactivity. Investigating such alterations in vivo is impossible. We hypothesised that these alterations are also present in fetoplacental vessels, since both vasculatures are exposed to the same circulating factors (e.g. endothelin-1) and respond similarly to certain stimuli (e.g. hypoxia). As proof-of-concept, we compared fetoplacental vasoreactivity between healthy and CDH-affected placentas. Methods: Fetoplacental vascular function of healthy and antenatally diagnosed left-sided CDH fetuses was assessed by wire myography. Placental expression of enzymes and receptors involved in the altered vasoreactive pathways was measured using quantitative PCR. Results: CDH arteries (n = 6) constricted more strongly to thromboxane A2 agonist U46619 (p &lt; 0.001) and dilated less to bradykinin (p = 0.01) and nitric oxide (NO)-donor sodium nitroprusside (p = 0.04) than healthy arteries (n = 8). Vasodilation to prostacyclin analogue iloprost and adenylate cyclase stimulator forskolin, and vasoconstriction to endothelin-1 were not different between both groups. Angiotensin II did not induce vasoconstriction. Phosphodiesterase inhibitors sildenafil and milrinone did not affect responses to sodium nitroprusside, forskolin, or U46619. The mRNA expression of guanylate cyclase 1 soluble subunit alpha 1 (p = 0.003) and protein kinase cyclic guanine monophosphate (cGMP)-dependent 1 (p = 0.02) were reduced in CDH versus healthy placentas. Discussion: The identified changes in the thromboxane and NO-cGMP pathways in the fetoplacental vasculature correspond with currently described alterations in the pulmonary vasculature in CDH. Therefore, fetoplacental arteries may provide an opportunity to predict pulmonary therapeutic responses in infants with CDH.</p

Soil-litter arthropod communities under pasture land use in southern Rwanda

peer reviewedLand use change caused by human activities is the main driver of biodiversity loss and changes in ecosystem functioning. However, less is known about how the conversion of a natural to pasture land favour the biological diversity of soil-litter arthropods to advance effective conservation plans and management systems. To fill the gap, this study focussed on soil-litter arthropod communities under a pasture land use in southern Rwanda. Data have been collected using pitfall traps and hand collection between April and June 2021. Sampled specimens of soil-litter arthropods have been identified to order and family levels by using dichotomous keys. Further, the species name was given when the identification key was available, while the morphological description was provided in absence of the identification keys. Results indicated a total of 3013 individuals of soil-litter arthropods grouped into 3 classes, 13 orders, 46 families and 87 morpho-species. Coleoptera showed a high number of families, while higher abundance and the number of morpho-species were found for ants (Hymenoptera: Formicidae). Higher abundance of sampled soil-litter arthropods is a sign that the studied area offers suitable habitat for soil-litter arthropods. However, less abundance found for some groups of soil-litter arthropods might be influenced by the used sampling techniques which were not appropriate for them. We recommend surveys using multiple sampling techniques to maximize chances of capturing a wide range of soil-litter arthropods

Integrated monitoring of nature restoration along ecotones, the example of the Yser Estuary

Within the framework of LIFE, one of the larger nature restoration projects in Flanders was realized on the right bank of the estuarine part of the Yser. General aim of the initiative was to restore or create beach-dune-salt marsh ecotones with salt-fresh, dynamic-stable, wet-dry and mud-sand ecotones. In order to reach this goal, several large buildings and roads were broken down, an entire tidal dock was restructured and some 500,000m³ of dredging material was removed to restore or create intertidal and coastal dune habitats and their connecting ecotones. Measures were taken to avoid abrupt topographical transitions along potential ecological gradients. It was decided to begin monitoring (2001-2004) from the very start of the restoration process (1999-2003). Monitoring was multidisciplinary and realized in a partnership between several scientific institutes (Ghent University, Catholic University of Louvain, Royal Belgian Institute of Natural Sciences and Institute of Nature Conservation with facility support of VLIZ). Monitoring included the most relevant abiotic conditions such as sedimentation and erosion, topography and ground water fluctuations, and biological response variables, i.e. flora and vegetation, terrestrial arthropods, benthic macrofauna and birds. It was decided to include two monitoring levels, an area-covering monitoring of the entire nature reserve (ca. 128ha) and a detailed monitoring of changes along transects perpendicular to the main ecological gradients. In this paper we present some results of the first three years of monitoring

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