International Council for the Exploration of the Sea (ICES) Annual Science Conference 2019, 9-12 September 2019 Gothenburg, Sweden.-- 1 page, figures Trawling activities are mainly driven by fishermen decisions on where to fish, market demands and fishing regulation. But, the ecological condition of benthic ecosystems feedback on fishermen through their ability to provide catch. In this complex interacting matrix, small decisions such as fishing over certain habitats, discarding fractions of the catch, or increasing effort can have significant effects through the system, with ultimate returns to the fishermen through profits. • This approach is used to explore the linkages between ecosystem components, services' provision, fishing activities and welfare in a coastal fishing area. • Major drivers identified by the BBN (e.g., benthic community structure or discards) should be used to identify management priorities and trade-offs, and develop strategies to achieve a balance of management targets. We applied a BBN approach to illustrate a Mediterranean trawling system, where fishing activities are regulated by effort limits, by-catch and discards are high, and profits are relatively high Funding: H2020-MSCA-IF-2016 [Project ID: 743545 and 746361] and MINOUW EU project (Project ID: 634495) This preliminar BBN illustrates expected links in the trawling system, with the environmental setting conditioning the catch biomass per unit of effort, while the final profits are conditioned by fish price, but also by labour costs (including costs for processing a discarded fractions) and fishing effort costs. Improved versions of the BBN will allow to explore the cascading effects of modifying decisions, such as fishing effort or discards, or optimise variables to maximise profits Coastal fisheries are complex socio-ecological systems controlled by the interaction between humans and the environment. Benthic ecosystems are shaped by trawling activities that are mainly driven by fishermen decisions on where to fish, by market demands and by fishing regulation. In return, changes in benthic ecosystems feedback on fishermen through their ability to provide food demands. In this complex interacting matrix, small decisions such as fishing over certain habitats, discarding fractions of the catch, or increasing effort can have significant and cascading effects through the system, with ultimate returns to the fishermen through overall catches and profits. We use a Bayesian Belief Network approach (BBN) to illustrate these multiple interactions in a Mediterranean trawling ground. The model relies on multiple data sources, including empirical data, long-term fishery registers, bio-economic models and expert knowledge. This approach is used to explore the linkages between ecosystem structure, services, human activities and welfare in a coastal fishing area. Major drivers identified by the BBN should be used to identify management priorities and trade-offs, and develop strategies to achieve a balance of management targets. The novelty of the approach is its ability to explore interactions by the integration of human dimensions into studies of ecosystem change, while it provides an illustrative interface for stakeholders Funding: H2020-MSCA-IF-2016 [Project ID: 743545 and 746361] and MINOUW EU project (Project ID: 634495)
Settling particles were collected using sediment traps deployed along three transects in the Lacaze-Duthiers and Cap de Creus canyons and the adjacent southern open slope from October 2005 to October 2006. The settling material was analyzed to obtain total mass fluxes and main constituent contents (organic matter, opal, calcium carbonate, and siliciclastics). Cascades of dense shelf water from the continental shelf edge to the lower continental slope occurred from January to March 2006. They were traced through strong negative near-bottom temperature anomalies and increased current speeds, and generated two intense pulses of mass fluxes in January and March 2006. This oceanographic phenomenon appeared as the major physical forcing of settling particles at almost all stations, and caused both high seasonal variability in mass fluxes and important qualitative changes in settling material. Fluxes during the dense shelf water cascading (DSWC) event ranged from 90.1 g m−2 d−1 at the middle Cap de Creus canyon (1000 m) to 3.2 g m−2 d−1 at the canyon mouth (1900 m). Fractions of organic matter, opal and calcium carbonate components increased seaward, thus diminishing the siliciclastic fraction. Temporal variability of the major components was larger in the canyon mouth and open slope sites, due to the mixed impact of dense shelf water cascading processes and the pelagic biological production. Results indicate that the cascading event remobilized and homogenized large amounts of material down canyon and southwardly along the continental slope contributing to a better understanding of the off-shelf particle transport and the internal dynamics of DSWC events.
Frigola, J.; Canals, M.; Cacho, I.; Moreno, A.; Sierro, F. J.; Flores, J. A.; Berné, S.; Jouet, G.; Dennielou, B.; Herrera, G.; +4 more
Frigola, J.; Canals, M.; Cacho, I.; Moreno, A.; Sierro, F. J.; Flores, J. A.; Berné, S.; Jouet, G.; Dennielou, B.; Herrera, G.; Pasqual, C.; Grimalt, J. O.; Galavazi, M.; Schneider, R.;
Project: EC | HERMIONE (226354)
Borehole PRGL1-4 drilled in the upper slope of the Gulf of Lion provides an exceptional record to investigate the impact of late Pleistocene orbitally-driven glacio-eustatic sea-level oscillations on the sedimentary outbuilding of a river fed continental margin. High-resolution grain-size and geochemical records supported by oxygen isotope chronostratigraphy allow reinterpreting the last 500 ka upper slope seismostratigraphy of the Gulf of Lion. Five main sequences, stacked during the sea-level lowering phases of the last five glacial-interglacial 100-kyr cycles, form the upper stratigraphic outbuilding of the continental margin. The high sensitivity of the grain-size record down the borehole to sea-level oscillations can be explained by the great width of the Gulf of Lion continental shelf. Sea level driven changes in accommodation space over the shelf cyclically modified the depositional mode of the entire margin. PRGL1-4 data also illustrate the imprint of sea-level oscillations at millennial time-scale, as shown for Marine Isotopic Stage 3, and provide unambiguous evidence of relative high sea-levels at the onset of each Dansgaard-Oeschger Greenland warm interstadial. The PRGL1-4 grain-size record represents the first evidence for a one-to-one coupling of millennial time-scale sea-level oscillations associated with each Dansgaard-Oeschger cycle.
The deep-sea hydrothermal vent mussel Bathymodiolus azoricus is a symbiont bearing bivalve that is found in great abundance at the Menez Gwen and Lucky Strike vent sites and in close vicinity off the Azores region near the Mid-Atlantic Ridge (MAR). The distinct relationships that vent mussels have developed with their physical and chemical environments are likely reflected in global gene expression profiles providing thus a means to distinguish geographically distinct vent mussels on the basis of gene expression studies, fluorescence in situ hybridization (FISH) experiments and 16S rRNA amplicon sequencing, to assess the natural expression of bacterial genes and vent mussel immune genes and the constitutive distribution and relative abundance of endosymbiotic bacteria within gill tissues. Our results confirmed the presence of methanotroph-related endosymbionts in Menez Gwen vent mussels whereas Lucky Strike specimens seem to harbor a different bacterial morphotype when a methane monooxygenase gene specific probe was used. No qualitative differences could be visualized between Menez Gwen and Lucky Strike individuals when tested with sulfur-oxidizing-related nucleic-acid probe. Quantitative PCR (qPCR) studies revealed varied gene expression profiles in both Menez Gwen and Lucky Strike mussel gill tissues for the immune genes selected. Genes encoding transcription factors presented noticeably low levels of fold expression whether in MG or LS animals whereas the genes encoding effector molecules appeared to have higher levels expression in MG gill tissues. The peptidoglycan recognition molecule, encoding gene, PGRP presented the highest level of transcriptional activity among the genes analyzed in MG gill tissues, seconded by carcinolectin and thus denoting the relevance of immune recognition molecules in early stage of the immune responses onset. Genes regarded as encoding molecules involved in signaling pathways were consistently expressed in both MG and LS gill tissues. Remarkably, the immunity-related GTPase encoding gene demonstrated in LS samples, the highest level of expression among the signaling molecule encoding genes tested when expressions levels were compared between MG and LG animals. A differential expression analysis of bacterial genes between MG and LS indicated a clear expression signature in LS gill tissues. The bacterial community structure ensued from the 16S rRNA sequencing analyses pointed at a unpredicted conservation of endosymbiont bacterial loads between MG and LS samples. Taken together, our results support the premise that Bathymodiolus azoricus exhibits different transcriptional statuses depending on which hydrothermal vent site it is collected from and within the same collection site while exhibiting differential levels of expression of genes corresponding to different immune functional categories. The present study represents a first attempt to characterize gene expression signatures in hydrothermal vent animals issued from distinct deep-sea environmental sites based on immune and bacterial genes expressions.
Roscoe, H. K.; Roozendael, M.; Fayt, C.; Piesanie, A.; Abuhassan, N.; Adams, C.; Akrami, M.; Cede, A.; Chong, J.; Clémer, K.; +41 more
Roscoe, H. K.; Roozendael, M.; Fayt, C.; Piesanie, A.; Abuhassan, N.; Adams, C.; Akrami, M.; Cede, A.; Chong, J.; Clémer, K.; Friess, U.; Gil Ojeda, M.; Goutail, F.; Graves, R.; Griesfeller, A.; Grossmann, K.; Hemerijckx, G.; Hendrick, F.; Herman, J.; Hermans, C.; Irie, H.; Johnston, P. V.; Kanaya, Y.; Kreher, K.; Leigh, R.; Merlaud, A.; Mount, G. H.; Navarro, M.; Oetjen, H.; Pazmino, A.; Perez-Camacho, M.; Peters, E.; Pinardi, G.; Puentedura, O.; Richter, A.; Schönhardt, A.; Shaiganfar, R.; Spinei, E.; Strong, K.; Takashima, H.; Vlemmix, T.; Vrekoussis, M.; Wagner, T.; Wittrock, F.; Yela, M.; Yilmaz, S.; Boersma, F.; Hains, J.; Kroon, M.; Piters, A.; Kim, Y. J.;
Project: EC | MEGAPOLI (212520)
In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.
Bottom trawling is a nonselective commercial fishing technique whereby heavy nets and gear are pulled along the seafloor, modifying the physical properties of seafloor sediments and altering natural sediment fluxes. Most studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments, where the capacity of trawling to modify the seafloor sediments coexists with high-energy natural processes driving sediment erosion, transport and deposition. Recent studies conducted on the Catalan margin have demonstrated that on continental slopes —where the sediment dynamics is less energetic— the reworking of the deep seafloor by bottom trawling produces periodic resuspension of surface sediments, and ultimately modifies the shape of the submarine landscape over large spatial scales. Trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep seafloor to become smoother over time, reducing its original complexity. These results suggest that during the last decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution Les dades presentades en aquest treball es van obtenir en el marc de diversos projectes de recerca: HERMIONE (226354 i CTM2010-11084-E), DOS MARES (CTM2010- 21810-C03), OASIS DEL MAR - Obra Social “la Caixa”, GRACCIE-CONSOLIDER (CSD2007- 00067) i REDECO (CTM2008-04973-E). Agraïm també el suport rebut per part del Govern Català als Grups de Recerca Consolidats (2009 SGR 899 i 1305) i l’ajut i assistència tècnica de les tripulacions dels vaixells oceanogràfics Hespérides, Sarmiento de Gamboa i García del Cid 8 pages, 9 figures Peer reviewed
Since the start of the HERMES and the HERMIONE projects, the margin of the Bay of Biscay has received special attention with respect to benthic ecosystems and sedimentary processes. The area is also known to be the historical cradle of cold-water coral studies by Joubin (1922) and Le Danois (1948). Already at that time the relationship between cold-water corals and fisheries were being discussed (with corals being a nuisance for fisheries!). Having performed previous work in the Whittard canyon (R/V Belgica 2006) and the Guilvinec canyon (R/V Belgica 2008), a joint marine geology and biology cruise was organized by the Renard Centre of Marine Geology and the Section of Marine Biology from Ghent University from 7 to 28 June 2010. The first leg (7-16 June, Zeebrugge-La Rochelle) focused on the Guilvinec canyon, while the second leg (19-28 June, La Rochelle-Zeebrugge) revisited several sites in the central Whittard canyon. The main objectives of this cruise were to (a) map and observe cold-water coral ecosystems on the canyon flanks with ROV Genesis, (b) obtain hydrographic data from CTD casts and water samples and (c) perform seabed multicoring for biology (descriptive and experimental research), biogeochemistry and sedimentology. In total, 23 scientists participated in this cruise, representing 10 institutes, among which were IFREMER, University College Cork and IFM-GeoMAR. The HERMIONE project is funded by the European Commission's Framework 7 Programme, under the theme "Environment (including climate change)". EC contract no. 226354. Peer reviewed 11 páginas