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International audience; Feed is the largest cost in animal production, therefore improving feed efficiency (FE) is one of the main priorities when redesigning farming systems. The objective of this work was to evaluate the effects of a divergent genetic selection for FE in Romane rams [i.e. efficient (RFI-) or inefficient (RFI+)] on the feed intake and nutrient digestibility of their daughters (ewes), reared in different conditions. Different to their sires, which were fed high concentrate-diets, the ewes were fed ad libitum total mixed ration (TMR) composed of silage (65%), hay (25%) and barley (10%). A series of in vivo digestibility trials were conducted using Romane ewes (n =20; 10 RFI- and 10 RFI+) during their 2 first production cycles. The BW, metabolic BW (MBW), body condition score (BCS), DM intake (DMI) and nutrient intake and digestibility were individually monitored. All parameters were significantly affected (P < 0.05) by the production cycle. The BW, MBW, BCS as well as the feed intake and nutrient digestibility were higher in the cycle 2 compared to cycle 1. The exception was the CP digestibility, which was higher in younger ewes (cycle 1). The BW and MBW was, as expected, higher in older ewes thus increasing the feed intake capacity in cycle 2 compared with cycle 1. Slight differences in TMR nutritive composition between the years of the study were also probably responsible of differences in CP digestibility. The RFI+ ewes showed a better BCS than RFI- ewes (3.0 vs. 2.7; P < 0.0001). In the conditions used in this study, we could not demonstrate any differences in intake and digestive efficiency between the two ewe FE lines, probably because the selected rams were tested with one diet (concentrate-based diet) whereas their daughters (ewes) with another (forage-based diet). Further research is warranted to evaluate RFI testing in animals fed a more fibrous diet closer to that of ewes under range conditions whereas also assessing responses to multiple-generation divergent selection on RFI.

Mid-latitude atmospheric elemental mercury (Hg) emissions undergo extensive oxidation to reactive Hg (RM) compounds during Arctic polar sunrise, resulting in enhanced atmospheric deposition that impacts Arctic marine wildlife and humans. It has been difficult to estimate RM dry deposition, because RM concentrations, compounds, and their deposition velocities are ill-defined. Here, we investigate RM concentrations sampled with membrane-based methods and find these to exceed denuder-based RM detection by 5 times at the Zeppelin Observatory on Svalbard (March 26–July 24, 2019). Measured dry deposition of gaseous oxidized Hg was about half of the modeled RM deposition, demonstrating that particulate-bound Hg was an important component of dry deposition. Using thermal membrane desorption, RM chemistry was found to be dominated by Hg–Cl/Br (51%) and Hg–N (45%) compounds. Back-trajectory analysis indicated that Hg–Br/Cl compounds were predominantly advected from within the marine boundary layer (sea ice exposure), while Hg–N originated from the free troposphere. Weekly average RM compound-specific dry deposition velocities ranged from 0.12 to 0.49 cm s–1, with a net RM dry deposition of 1.9 μg m–2 (1.5–2.5 μg m–2; 95% confidence interval) that exceeds the mean annual Hg wet deposition flux in Svalbard. Overall, we find that springtime atmospheric RM deposition has been underestimated in the Arctic marine environment. ACS Earth and Space Chemistry, 5 (11) ISSN:2472-3452

Philosophical Transactions of the Royal Society B: Biological Sciences, 375 (1810) ISSN:0962-8436 ISSN:1471-2970

Abstract Human pressure leaves a mark on coastal ecosystems that can be used to study the ecology of marine species. This study compared the trace elements (TEs) composition and isotopic niche metrics of the squid Loligo vulgaris, the cuttlefish Sepia officinalis and the octopus Octopus vulgaris in the western Mediterranean Sea. The results revealed that anthropogenic pressure clearly affected coastal waters and the habitat use of these three cephalopods. Anthropogenic pressure in coastal areas, measured by the LUSI index, correlated with the TEs composition of cephalopods. The DistLM analysis showed that Cr and Zn were strong predictor variables of the LUSI matrix on all three cephalopod species. In this study, isotopic niche, combined with the CAP analysis of TEs, were plotted in a bivariate manner, which could refer to an “anthropo-niche”. We provide a useful heuristic scheme for analyzing the interplay among coastal influence, trophic level, and the TEs from environment.

Retention soil filters (RSFs) are vertical flow constructed wetlands. They are mainly used for the treatment of combined sewer overflow or stormwater, and not operated during dry weather conditions. However, RSFs have been successfully tested as continuous post treatment for sewage treatment plant effluents. In this paper we present a new approach, namely dual usage of the retention soil filter. During dry weather the RSF is used for the polishing treatment of sewage treatment plant effluent and during overflow events, the retention soil filter treats the combined sewer overflow. This study was conducted at two pilot RSFs that were fed with sewage treatment effluent for four years. Removal of TOC, DOC, nutrients and 21 organic micropollutants was determined during six months at different sequences of regular effluent and overflow treatment conditions. TOC, DOC and nutrients, appearing in high concentration in combined sewer overflow, were effectively removed, and metformin and caffeine micropollutants showed >99% removal. Residues from this combined sewer treatment that were sorbed on filter material or stored in pore water were washed out directly after treatment when STP effluent infiltration was initiated. This effect declined within 20 h after combined sewer overflow treatment. Dry periods of 18 h between combined sewer and sewage treatment plant effluent feeding counteracted the wash out effects. The highest removal efficiency was found in the beginning of the feeding time of 28 h, indicating that shorter feeding cycles enhance the overall efficiency of the RSF. Finally, the results show that a single RSF system can successfully reduce emissions of TOC, DOC, nutrients and micropollutants to surface waters from two different emission pathways, i.e. from regular treated effluents and storm related sewer overflows. In conclusion, the dual usage of RSF is a promising approach and ready for upscaling and implementation.

Ministerio de Ciencia, Innovacion y Universidades PTA2015-10829-I European Regional Development Fund - Foundation Albert II Monaco Postdoctoral contract Juan de la Cierva [IJCI-2016-29329] Interreg Med Programme MPA-Adapt 1MED15_3.2_M2_337 Ministry of Education, Spain FPU15/05457 European Union’s Horizon 2020