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مصطلحات موضوعية: Bio Process Engineering, Earth Observation and Environmental Informatics, Aquatic Ecology and Water Quality Management, Bos- en Landschapsecologie, Water en Voedsel, WASS, Business Manager projects Mid-South, Hydrology and Quantitative Water Management, Biodiversity and Policy, Onderz. Form. D, Marine Animal Ecology, Staf Corporate Strategy & Accounts, Aquaculture and Fisheries, Aardobservatie en omgevingsinformatica, Biodiversiteit en Beleid, Forest and Landscape Ecology, Vegetatie, VLAG, Advisory B, Milieubeleid, WIMEK, Water and Food, Vegetation, Aquacultuur en Visserij, Business Manager projecten Midden-Noord, Farm Systems Ecology Group, Mariene Dierecologie, Staff Corporate Strategy & Accounts, Aquatische Ecologie en Waterkwaliteitsbeheer, PE&RC, Biosystematiek, Environmental Policy, Climate Resilience, BBP Bioconversion, Klimaatbestendigheid, Wildlife Ecology and Conservation, WIAS, Biosystematics, Business Manager projects Mid-North, Business Manager projecten Midden-Zuid, Hydrologie en Kwantitatief Waterbeheer
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dris___00893::7fef39d0cbb915c67de8ced68f1633e0Test
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المؤلفون: Troost, K., van Asch, M., Cornelisse, S., Glorius, S., van den Ende, D., van Es, Y., Keur, M., Perdon, K.J., van der Pool, J., Suykerbuyk, W., van Zweeden, C., van Zwol, J.
مصطلحات موضوعية: Onderzoeksassistenten, Business Manager projecten Midden-Noord, Onderz. Form. B, Life Science, Business Manager projects Mid-South, Business Manager projects Mid-North, Business Manager projecten Midden-Zuid
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::d0a1543da0e2cc5cc336ceb4f16bb476Test
https://research.wur.nl/en/publications/schelpdierbestanden-in-de-nederlandse-kustzone-waddenzee-en-zoute-3Test -
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المؤلفون: Bleeker, K., Overzee, H.M.J., Dammers, M.
مصطلحات موضوعية: Onderzoeksassistenten, Life Science, Business Manager projects Mid-South, Business Manager projecten Midden-Zuid
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::e62ed9001392f9e8436eecc9086abc6aTest
https://research.wur.nl/en/publications/discard-self-sampling-of-the-dutch-bottom-trawl-fisheries-in-2021Test -
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المؤلفون: Hamer, Alicia, Foekema, Edwin
مصطلحات موضوعية: Onderz. Form. D, Onderz. Form. B, Life Science, Business Manager projects Mid-South, Business Manager projecten Midden-Zuid
الوصف: In order to quantify the amount of carbonate, precipitated as calcium-carbonate in the shells of blue mussel (Mytilus edulis) in a temperate climate, an existing Dynamic Energy Budget (DEB) model for the blue mussel was adapted by separating shell growth from soft tissue growth. Hereby, two parameters were added to the original DEB-model, a calcification cost [J/mgCaCO3] and an energy allocation fraction [-], which resulted in the energy allocated for structural growth being divided between shell and meat growth. As values for these new parameters were lacking, they were calibrated by fitting the model to field data. Calibration results showed that an Energy allocation fraction of 0.5 and a calcification cost of 0.9 J/mgCaCO3, resulted in the best fit when fitted on 2017 and 2018 field data separately. These values however, show the best fit for data obtained within the first couple of years of the shellfish life, and do not take later years into account. Also it could be discussed that some parameters vary throughout the lifespan of the species. The results were compared to a regular DEB model, where the shell output was calculated through a simple allometric relationship. It is sometimes assumed that the carbon storage in shell material as calcium carbonate could be regarded as a form of carbon sequestration, with a positive impact on the atmospheric CO2 concentrations. However, studies on the physical-chemical processes related to shell formation have shown that from an oceanographic perspective, shell formation should be regarded as a source of atmospheric CO2 rather than a sink. The removal of carbonates, through the biocalcification process, reduces the buffer capacity (alkalinity) of the water to store CO2. As a result CO2 is released from the water to the atmosphere when shell material is formed. The actual amount of CO2 that escapes from the water to the atmosphere as a result of biocalcification depends strongly on local water characteristics. In this study, the effect of calcification by mussels on the CO2 flux to the atmosphere is studied using an adapted DEB model where energy costs of calcification are modelled explicitly. The model was subsequently run under two future climate scenarios, (RCP 4.5 and RCP 8.3) with elevated temperature and decreased pH, and the total released CO2 as a result of shell formation was calculated with the SeaCarb model. This showed growth of mussels, under future climate conditions to be slower, and with that the cumulative shell mass and carbonate precipitated to CaCO3 to decrease. Yet the amount of CO2 released, due to biocalcification, increased. This is due to the fact that the amount of CO2 released/gr of CaCO3 precipitated will be higher, as a result of the decreased buffering capacity of seawater under future climatic environmental conditions. In summary the conclusions of the project were: • Biocalcification (shell formation) of marine organisms, such as bivalves, cannot be regarded as a process resulting in negative CO2 emission to the atmosphere; • The actual amount of CO2 that, due to biocalcification, is released from the water to the atmosphere depends on the physicochemical characteristics of the water, which are influenced by (future) climate conditions; • Our first model calculations suggest that at future climate conditions mussel’s grow rate will be somewhat reduced. While the amount of CO2 that due to biocalcification, escapes to the atmosphere during its life-time will slightly increase. Making the ratio of g CO2 release/g CaCO3 precipitated slightly higher; • Our model calculations should be considered an exercise rather than a definite prediction of how mussels will respond to future climate scenarios. Additional information/experimentation is strongly needed to validate the model settings, and to test the validity of the above mentioned outcome of the model.
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dedup_wf_001::1b417e612c23282667ae6e0f06bc2f4bTest
https://research.wur.nl/en/publications/model-development-to-assess-carbon-fluxes-during-shell-formationTest- -
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المؤلفون: van de Pol, L., Schram, E.
المصدر: Visserijnieuws, 43(18), 6-6
مصطلحات موضوعية: Business Manager projects Mid-South, Business Manager projecten Midden-Zuid
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=narcis______::962616f0d72b36958a85190ae9d96e95Test
https://research.wur.nl/en/publications/overlevingskansen-van-roggen-als-ze-terug-in-zee-gezet-worden-ondTest -
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المصدر: PLoS ONE. 18(6)
مصطلحات موضوعية: Biometris, Aquaculture and Fisheries, Aquacultuur en Visserij, WIAS, Business Manager projects Mid-South, Business Manager projecten Midden-Zuid
الوصف: Undersized European plaice dominate the discarded fraction of the catch of the beam trawl fisheries for sole in the Southern North Sea. Effects of environmental conditions at sea and of the use of a water-filled hopper on the survival of undersized European plaice discarded by pulse trawl fisheries were explored. During trips with commercial pulse-trawlers catches were discharged in either water-filled hoppers or conventional dry hoppers. For both hoppers, undersized plaice were sampled from the sorting belt. After assessment of vitality status, sampled fish were housed in dedicated survival monitoring tanks on board. Upon return in the harbour fish were transferred to the laboratory to monitor their survival for up to 18 days post-catch. Conditions at sea, such as wave height and water temperature, as prevailing during these trips were recorded or obtained from public data sources. The overall estimate for the survival probability for plaice discarded by pulse trawl fisheries is 12% (95% CI: 8% - 18%). Both water temperature and vitality status had strong effects on survival probabilities of discarded plaice. Increasing water temperature increased mortality. The vitality of the fish could be moderately increased by using a water-filled hopper to collect the fish on deck, but we found no significant direct effect of hopper type on plaice discard survival. It seems that to increase discards survival, fish need to be landed on deck in much better condition by a reduction of the impact of capture and hauling processes on fish condition
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dris___00893::41614cff80c815d915929a46415d6c99Test
https://doi.org/10.1371/journal.pone.0287020Test -
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المؤلفون: Linda Tonk, Rob Witbaard, Pim van Dalen, Chiu H. Cheng, Pauline Kamermans
المصدر: Aquatic Living Resources 36 (2023) 6
Aquatic Living Resources, 36(6)مصطلحات موضوعية: Onderzoeksassistenten, Onderz. Form. D, Business Manager projecten Midden-Noord, Ecosystemen, WIAS, Life Science, Aquatic Science, Business Manager projects Mid-South, Business Manager projects Mid-North, Business Manager projecten Midden-Zuid
الوصف: Innovative techniques are needed to assess oyster performance in flat oyster reef restoration projects. A valve gape monitor, a device that continuously measures opening and closing of live bivalves, can potentially be used as an effective method to determine survival and behaviour of the European flat oyster Ostrea edulis. The method has been successfully used in combination with a number of bivalve species to investigate valve gape activity in response to environmental factors. In this study, eight O. edulis were equipped with valve gape sensors in order to relate gape to environmental conditions such as food availability. Valve gape activity was monitored under controlled laboratory conditions, with and without food, in a concrete basin in the Oosterschelde and in the field (Voordelta, Dutch North Sea). Under controlled laboratory conditions, oysters clearly responded to changes in food availability. Starved oysters closed their valves significantly longer than oysters that received food, and the relative gape width in fed oysters was larger. In the concrete basin (Oosterschelde), a positive correlation between valve opening and Chlorophyll-a was found. Additionally, valve gape activity and tidal movement appeared to be linked. When exposed to a full tidal cycle (Voordelta), a negative correlation between valve opening and Chlorophyll-a was found. However, there was no correlation between valve gape and current velocity. In autumn, longer periods of inactivity were seen, but when valves opened, the valve gape was larger. These data indicate that valve gape can provide valuable information on behaviour (gape frequency and gape width), but also show that it is not necessarily a good proxy for feeding rate. Nevertheless, these results show that the gape monitor can be used to determine the natural behaviour of flat oysters under field conditions, and that gape opening provides information on behaviour and the stress response of bivalves to environmental conditions.
وصف الملف: application/pdf
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b8d28016bcd51a38c9c67d4907299f5bTest
https://research.wur.nl/en/publications/applicability-of-the-gape-monitor-to-study-flat-oyster-ostrea-eduTest -
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مصطلحات موضوعية: Onderz. Form. D, Business Manager projecten Midden-Noord, Onderz. Form. B, Business Manager projects Mid-South, Business Manager projects Mid-North, Business Manager projecten Midden-Zuid
الوصف: 4 van 48 | Wageningen Marine Research rapport C012/23 Samenvatting Rijkswaterstaat heeft op de Eems een opgave om de toegangsgeul naar de Eemshaven bereikbaar te houden voor schepen met een diepgang tot 14m (Panamax). Rijkswaterstaat heeft een Duitse vergunning om de baggerspecie te verspreiden op verspreidingslocatie P0 in de Eems, op Duits grondgebied. Voorwaarden vanuit deze vergunning is dat 1) monitoring van de effecten op bodemfauna dient te worden uitgevoerd en 2) de ecologische impact op het gehele natuurgebied Borkum Riffgrund dient te worden vastgesteld. Monitoring van de bodemfauna is uitgevoerd in de jaren 2020, 2021 en 2022, met bemonsteringen in het voor- en najaar. Het verspreidingsgebied is sinds 2020 ieder jaar gebruikt in de periode tussen 1 juni en 31 september, de ruiperiode van de zwarte zee-eend. Dit rapport, een tweede tussenrapportage, beschrijft de resultaten van de monitoring en veranderingen in 2020, 2021 en 2022. Er is in alle jaren zowel in het voor- als najaar, na het verspreiden van de baggerspecie, bemonsterd met een van Veen-happer (infauna) en een Kieler Kinderwagen (epifauna), binnen het verspreidingsgebied en in een referentiegebied, deels ten oosten en deels ten westen van het referentiegebied gelegen. Na het verspreiden van baggerspecie wordt het sediment in het verspreidingsgebied fijnzandiger. Nadien neemt de mediane korrelgrootte weer toe. De mediane korrelgrootte is in het najaar is steeds significant lager in het verspreidingsgebied dan in het referentiegebied. Vooralsnog zijn er weinig verschillen in de bodemfauna vastgesteld gerelateerd aan het gebruik van P0 als verspreidingslocatie, wellicht omdat het om een soortenarm gebied gaat met lage dichtheden, zowel per soort als totaal. Opgemerkt moet wel worden dat een aantal factoren het trekken van deze conclusies bemoeilijkt: 1) het sediment en de fauna in het oostelijk en westelijk deel van het referentiegebied verschillen, 2) er is niet over de hele verspreidingslocatie verspreid, en 3) het onderscheidingsvermogen laag is, door de lage hoeveelheid bemonsterpunten. Omdat er geen aanwijzingen zijn voor enig effect in de referentiegebieden, is ook geen effect te verwachten op de bodemdiergemeenschap in het natuurgebied Borkum Riff, waar P0 ligt. Het onderzoeksgebied ligt binnen het gebied “Schiermonnikoog-Rottum-Borkum” waar soms grote aantallen zwarte zee-eenden kunnen zitten, als de voedselomstandigheden daar gunstig zijn (veel Spisula of jonge Ensis). Een locatie als P0 waar weinig voedsel voorkomt, zal voor eenden als foerageergebied niet aantrekkelijk zijn maar mogelijk wel als tijdelijke rustplaats. Eenden op die locatie zijn dan eenden die verstoord werden op de plek waar ze eigenlijk liever zitten en hun aanwezigheid is hier kort durend. Zolang daar geen rijke bodemfauna aanwezig is, is hier voor eenden niets anders te halen dan rust.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dris___00893::16ec1ed31a04759603d9e6b211174f47Test
https://doi.org/10.18174/591337Test -
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مصطلحات موضوعية: Onderz. Form. D, Onderz. Form. B, Business Manager projects Mid-South, Business Manager projecten Midden-Zuid
الوصف: In order to quantify the amount of carbonate, precipitated as calcium-carbonate in the shells of blue mussel (Mytilus edulis) in a temperate climate, an existing Dynamic Energy Budget (DEB) model for the blue mussel was adapted by separating shell growth from soft tissue growth. Hereby, two parameters were added to the original DEB-model, a calcification cost [J/mgCaCO3] and an energy allocation fraction [-], which resulted in the energy allocated for structural growth being divided between shell and meat growth. As values for these new parameters were lacking, they were calibrated by fitting the model to field data. Calibration results showed that an Energy allocation fraction of 0.5 and a calcification cost of 0.9 J/mgCaCO3, resulted in the best fit when fitted on 2017 and 2018 field data separately. These values however, show the best fit for data obtained within the first couple of years of the shellfish life, and do not take later years into account. Also it could be discussed that some parameters vary throughout the lifespan of the species. The results were compared to a regular DEB model, where the shell output was calculated through a simple allometric relationship. It is sometimes assumed that the carbon storage in shell material as calcium carbonate could be regarded as a form of carbon sequestration, with a positive impact on the atmospheric CO2 concentrations. However, studies on the physical-chemical processes related to shell formation have shown that from an oceanographic perspective, shell formation should be regarded as a source of atmospheric CO2 rather than a sink. The removal of carbonates, through the biocalcification process, reduces the buffer capacity (alkalinity) of the water to store CO2. As a result CO2 is released from the water to the atmosphere when shell material is formed. The actual amount of CO2 that escapes from the water to the atmosphere as a result of biocalcification depends strongly on local water characteristics. In this study, the effect of calcification by mussels on the CO2 flux to the atmosphere is studied using an adapted DEB model where energy costs of calcification are modelled explicitly. The model was subsequently run under two future climate scenarios, (RCP 4.5 and RCP 8.3) with elevated temperature and decreased pH, and the total released CO2 as a result of shell formation was calculated with the SeaCarb model. This showed growth of mussels, under future climate conditions to be slower, and with that the cumulative shell mass and carbonate precipitated to CaCO3 to decrease. Yet the amount of CO2 released, due to biocalcification, increased. This is due to the fact that the amount of CO2 released/gr of CaCO3 precipitated will be higher, as a result of the decreased buffering capacity of seawater under future climatic environmental conditions. In summary the conclusions of the project were: • Biocalcification (shell formation) of marine organisms, such as bivalves, cannot be regarded as a process resulting in negative CO2 emission to the atmosphere; • The actual amount of CO2 that, due to biocalcification, is released from the water to the atmosphere depends on the physicochemical characteristics of the water, which are influenced by (future) climate conditions; • Our first model calculations suggest that at future climate conditions mussel’s grow rate will be somewhat reduced. While the amount of CO2 that due to biocalcification, escapes to the atmosphere during its life-time will slightly increase. Making the ratio of g CO2 release/g CaCO3 precipitated slightly higher; • Our model calculations should be considered an exercise rather than a definite prediction of how mussels will respond to future climate scenarios. Additional information/experimentation is strongly needed to validate the model settings, and to test the validity of the above mentioned outcome of the model.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=dris___00893::a8ccf527e773475b86bdbc8e4691c65dTest
https://doi.org/10.18174/589191Test
