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Seawater carbonate chemistry and physiology of Baltic blue mussels (Mytilus edulis)

Increased maintenance costs at cellular, and consequently organism level, are thought to be involved in shaping the sensitivity of marine calcifiers to ocean acidification (OA). Yet, knowledge of the capacity of marine calcifiers to undergo metabolic adaptation is sparse. In Kiel Fjord, blue mussels thrive despite periodically high seawater PCO2, making this population interesting for studying metabolic adaptation under OA. Consequently, we conducted a multi-generation experiment and compared physiological responses of F1 mussels from 'tolerant' and 'sensitive' families exposed to OA for 1 year. Family classifications were based on larval survival; tolerant families settled at all PCO2 levels (700, 1120, 2400 µatm) while sensitive families did not settle at the highest PCO2 (>=99.8% mortality). We found similar filtration rates between family types at the control and intermediate PCO2 level. However, at 2400 µatm, filtration and metabolic scope of gill tissue decreased in tolerant families, indicating functional limitations at the tissue level. Routine metabolic rates (RMR) and summed tissue respiration (gill and outer mantle tissue) of tolerant families were increased at intermediate PCO2, indicating elevated cellular homeostatic costs in various tissues. By contrast, OA did not affect tissue and routine metabolism of sensitive families. However, tolerant mussels were characterised by lower RMR at control PCO2 than sensitive families, which had variable RMR. This might provide the energetic scope to cover increased energetic demands under OA, highlighting the importance of analysing intra-population variability. The mechanisms shaping such difference in RMR and scope, and thus species' adaptation potential, remain to be identified.

Seawater carbonate chemistry and physiological performance parameters of Carcinus maenas under respective incubation conditions

Ocean acidification causes an accumulation of CO2 in marine organisms and leads to shifts in acid-base parameters. Acid-base regulation in gill breathers involves a net increase of internal bicarbonate levels through transmembrane ion exchange with the surrounding water. Successful maintenance of body fluid pH depends on the functional capacity of ion-exchange mechanisms and associated energy budget. For a detailed understanding of the dependence of acid-base regulation on water parameters, we investigated the physiological responses of the shore crab Carcinus maenas to 4 weeks of ocean acidification [OA, P(CO2)w = 1800 µatm], at variable water bicarbonate levels, paralleled by changes in water pH. Cardiovascular performance was determined together with extra-(pHe) and intracellular pH (pHi), oxygen consumption, haemolymph CO2 parameters, and ion composition. High water P(CO2) caused haemolymph P(CO2) to rise, but pHe and pHi remained constant due to increased haemolymph and cellular [HCO3-]. This process was effective even under reduced seawater pH and bicarbonate concentrations. While extracellular cation concentrations increased throughout, anion levels remained constant or decreased. Despite similar levels of haemolymph pH and ion concentrations under OA, metabolic rates, and haemolymph flow were significantly depressed by 40 and 30%, respectively, when OA was combined with reduced seawater [HCO3-] and pH. Our findings suggest an influence of water bicarbonate levels on metabolic rates as well as on correlations between blood flow and pHe. This previously unknown phenomenon should direct attention to pathways of acid-base regulation and their potential feedback on whole-animal energy demand, in relation with changing seawater carbonate parameters.

Seawater carbonate chemistry and gastric pH homeostasis and larval recruitment in the sea star Asterias rubens

Aim: Experimental simulation of near‐future ocean acidification (OA) has been demonstrated to affect growth and development of echinoderm larval stages through energy allocation towards ion and pH compensatory processes. To date, it remains largely unknown how major pH regulatory systems and their energetics are affected by trans‐generational exposure to near‐future acidification levels. Methods: Here, we used the common sea star Asterias rubens in a reciprocal transplant experiment comprising different combinations of OA scenarios, to study trans‐generational plasticity using morphological and physiological endpoints. Results: Acclimation of adults to pHT 7.2 (pCO2 3500 μatm) led to reductions in feeding rates, gonad weight and fecundity. No effects were evident at moderate acidification levels (pHT 7.4; pCO2 2000 μatm). Parental pre‐acclimation to pHT 7.2 for 85 days reduced developmental rates even when larvae were raised under moderate and high pH conditions, whereas pre‐acclimation to pHT 7.4 did not alter offspring performance. Microelectrode measurements and pharmacological inhibitor studies carried out on larval stages demonstrated that maintenance of alkaline gastric pH represents a substantial energy sink under acidified conditions that may contribute up to 30% to the total energy budget. Conclusion: Parental pre‐acclimation to acidification levels that are beyond the pH that is encountered by this population in its natural habitat (eg, pHT 7.2) negatively affected larval size and development, potentially through reduced energy transfer. Maintenance of alkaline gastric pH and reductions in maternal energy reserves probably constitute the main factors for a reduced juvenile recruitment of this marine keystone species under simulated OA.

Seawater carbonate chemistry and behavioural trait expression of polar invertebrates

Here, we examine the ecosystem ramifications of changes in sediment-dwelling invertebrate bioturbation behaviour—a key process mediating nutrient cycling—associated with nearfuture environmental conditions (+ 1.5 °C, 550 ppm [pCO2]) for species from polar regions experiencing rapid rates of climate change. This dataset is included in the OA-ICC data compilation maintained in the framework of the IAEA Ocean Acidification International Coordination Centre (see https://oa-icc.ipsl.fr). Original data were downloaded from Polar Data Centre (see Source) by the OA-ICC data curator. In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2024) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2024-07-11.

Impact of ocean acidification on thermal tolerance and acid-base regulation of Mytilus edulis (L.) from the North Sea

Observational dataset of behavioral response of three-spined sticklebacks to TNT exposure in a closed laboratory setup

Dumped munition in the German North Sea and Baltic Sea pose environmental risks as corrosion of the munition shells results in the leakage of the explosive 2,4,6-trinitroluene (TNT) into the marine environment. Uptake of TNT by marine biota and the associated negative effects on organisms are of major concern. This dataset reports behavioral responses of three-spined stickleback (Gasterosteus aculeatus) to environmentally relevant concentrations of TNT. Experimental sticklebacks were laboratory-bred and held in groups of 30 individuals in 60 L tanks in the fish facilities at the Thünen Institute of Fisheries Ecology in Bremerhaven. Parental sticklebacks originated from the Weser estuary (Luneplate, Bremerhaven, Germany, 53°28'36.9" N; 8°31'08.9" E) and were collected in April 2023. A total of 60 sticklebacks were tested in a controlled laboratory setup at the fish facilities at the Thünen Institute in Bremerhaven, containing two hideout zones formed by artificial plants. Each hideout was connected to an infusion system delivering either a TNT solution (100 µg/L) or control water into the zone currently occupied by the fish. Experimental trials were video-recorded to enable post hoc behavioral analysis. Behavioral metrics included the total time spent in the exposed hideout zone (s), latency to first leave the exposed hideout zone (s), and the number of crossings between hideout zones.

Growth and behaviour of Baltic spring spawning herring (Clupea harengus) larvae raised at two different temperatures and under different feeding regimes (prey size) using the copepod Acartia tonsa: growth

Ten female (mean 179 g wet mass (WM) and 25.3 cm standard length (SL) and ten male (182 g WM, 24.5 cm SL) Atlantic herring (Clupea harengus L.) were obtained from Kiel Bight (54°22'N, 010°09'E) and strip-spawned. Their offspring were subjected to feeding and growth experiments using different prey size spectra in controlled laboratory settings at different temperatures. In 4- (13°C) or 7-day (7°C) experiments, the effect of prey size on larval foraging behaviour, specific growth rate (SGR) and biochemical condition (RNA:DNA, RD) was tested. On a daily basis, the swimming behaviour and foraging activity of these larvae was recorded.

Growth and behaviour of Baltic spring spawning herring (Clupea harengus) larvae raised at two different temperatures and under different feeding regimes (prey size) using the copepod Acartia tonsa: behaviour

Ten female (mean 179 g wet mass (WM) and 25.3 cm standard length (SL) and ten male (182 g WM, 24.5 cm SL) Atlantic herring (Clupea harengus L.) were obtained from Kiel Bight (54°22'N, 010°09'E) and strip-spawned. Their offspring were subjected to feeding and growth experiments using different prey size spectra in controlled laboratory settings at different temperatures. In 4- (13°C) or 7-day (7°C) experiments, the effect of prey size on larval foraging behaviour, specific growth rate (SGR) and biochemical condition (RNA:DNA, RD) was tested. On a daily basis, the swimming behaviour and foraging activity of these larvae was recorded.

Growth and behaviour of Baltic spring spawning herring (Clupea harengus) larvae raised at two different temperatures and under different feeding regimes (prey size) using the copepod Acartia tonsa

Ten female (mean 179 g wet mass (WM) and 25.3 cm standard length (SL) and ten male (182 g WM, 24.5 cm SL) Atlantic herring (Clupea harengus L.) were obtained from Kiel Bight (54°22'N, 010°09'E) and strip-spawned. Their offspring were subjected to feeding and growth experiments using different prey size spectra in controlled laboratory settings at different temperatures. In 4- (13°C) or 7-day (7°C) experiments, the effect of prey size on larval foraging behaviour, specific growth rate (SGR) and biochemical condition (RNA:DNA, RD) was tested. On a daily basis, the swimming behaviour and foraging activity of these larvae was recorded.

Rindviehhaltung: tiergerecht und emissionsarm - Tiergerechte Laufflächen und emissionsarme Stallsysteme für Rindvieh

Ziele: 1. Maßnahmen zur Vermeidung von Klauenproblemen bei Neubauten und Sanierungen liegen vor. 2. Tiergerechte kostengünstige Laufflächen sind entwickelt. Maßnahmen zur Erhaltung der Trittsicherheit von Laufflächen sind bekannt. 3. Ammoniakemissionen sind für ausgewählte Stallsysteme und verschiedene Bodenausführungen bekannt. 4. Empfehlungen für emissionsoptimierte Stallsysteme liegen vor. 5. Eine Methodik zur Interessenabwägung in der Tierhaltung ist erarbeitet. 6. Diese Methodik ist an Fallbeispielen erprobt und bietet Vorschläge zur Neukonzeption von Stallsystemen. Problemstellung: Laufflächen müssen die Anforderungen der Tiere (Trittsicherheit, Klauengesundheit) berücksichtigen. Lösungsansätze wie Mikro- und Makrorauheit (Profilierung) können die Trittsicherheit des Bodens erhöhen, sind jedoch auch mit möglichen Nachteilen wie zu starkem Klauenabrieb oder Beeinträchtigung der Reinigungsqualität verbunden. Verformbare Bodenbeläge reduzieren Klauenabnutzung, sind mit hohen Einbaukosten verbunden und können eine geringere Haltbarkeit aufweisen. Jede Bodengestaltung stellt spezifische Anforderungen an die Entmistungstechnik. Mit angepasster Reinigungstechnik, Verbesserungen bei Management und Arbeitsorganisation ist eine hohe Reinigungsqualität anzustreben. Laufflächen sollen in neu eingebautem Zustand und auch nach mehreren Jahren noch trittsicher sein. Bodenbeläge sind daher mit Blick auf deren Verschleißfestigkeit zu optimieren. Drei Viertel der Ammoniakemissionen in der Schweiz sind direkt oder indirekt auf die Nutztierhaltung zurückzuführen. Die Stofffreisetzung hängt von physiologischen, biochemischen, kontaktflächen-, stoff- und luftgebundenen Faktoren ab. Die Größe, Anordnung und Bodenbeschaffenheit des Laufbereichs, die Entmistungstechnik und das Management haben einen großen Einfluss auf die Freisetzung von Ammoniak. Emissionsfaktoren bei Ställen mit freier Lüftung und für Ausläufe fehlen. In der Schweiz sind auch perforierte Laufhöfe auf Güllengruben angeordnet. Erforderlich sind emissionsoptimierte Stallsysteme oder eine Neukonzeption von Ställen, die zugleich tier- und umweltgerecht sind. Eine transparente Interessenabwägung zwischen den Bereichen Tierwohl, Emissionen, Arbeitswirtschaft und Kosten fehlt bisher. Bei der Weiterentwicklung von Systemen der Nutztierhaltung ist in Zukunft verstärkt darauf zu achten, dass Tiergerechtheit, Umweltverträglichkeit und Wirtschaftlichkeit im Einklang sind.

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