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Seawater carbonate chemistry and benthic marine community during experiments, 2011

<p>Ocean acidification is predicted to impact all areas of the oceans and affect a diversity of marine organisms. However, the diversity of responses among species prevents clear predictions about the impact of acidification at the ecosystem level. Here, we used shallow water CO2 vents in the Mediterranean Sea as a model system to examine emergent ecosystem responses to ocean acidification in rocky reef communities. We assessed in situ benthic invertebrate communities in three distinct pH zones (ambient, low, and extreme low), which differed in both the mean and variability of seawater pH along a continuous gradient. We found fewer taxa, reduced taxonomic evenness, and lower biomass in the extreme low pH zones. However, the number of individuals did not differ among pH zones, suggesting that there is density compensation through population blooms of small acidification-tolerant taxa. Furthermore, the trophic structure of the invertebrate community shifted to fewer trophic groups and dominance by generalists in extreme low pH, suggesting that there may be a simplification of food webs with ocean acidification. Despite high variation in individual species' responses, our findings indicate that ocean acidification decreases the diversity, biomass, and trophic complexity of benthic marine communities. These results suggest that a loss of biodiversity and ecosystem function is expected under extreme acidification scenarios.</p>

Analyse der physiologischen Grundlagen interspezifischer Tiervergesellschaftungen und strukturelle und physiologische Mechanismen der Umweltanpassung von Tieren

Es wird untersucht, welche physiologischen, ethologischen und oekologischen Voraussetzungen erfuellt sind, damit es zum Zusammenleben artverschiedener Tiere im marinen Bereich kommt. Es werden die Signale bzw. Kommunikationsmoeglichkeiten, die haeufig chemischer Natur sind, analysiert.

End biodiversity loss through improved tracking of threatened invertebrates

In today's biodiversity crisis, there is an urgent need to monitor terrestrial and aquatic species in their natural habitats, especially those that may be endangered, invasive or elusive. Traditional species observation methods, based on acoustic or observational surveys are inefficient, costly and time consuming. On the other hand, DNA is continuously deposited in the environment from natural processes and this environmental DNA (eDNA) allows us to detect species and reconstruct their communities with a high level of sensitivity. These data can be used to obtain occurrence records and to collect more population information in field. Crucially, these data are necessary to inform management agencies about the current state of our biodiversity, and are especially urgent for species that are currently data deficient. The aims of this study are to firstly identify occurrence records from diverse sources (databases, literature) and generate a database of distributional data for species of crustacean and mollusks that are data deficient in Sweden. Secondly, we aim to detect threatened species in Swedish marine, freshwater and terrestrial habitats using novel genomic methods (DNA metabarcoding, ddPCR). Finally, based on the new data, we will run species distribution and population models, to improve information on geographic range and population status for threatened invertebrates. The results will be integrated into current monitoring programmes (e.g. red-listing) and action plans.

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 in situ and laboratory measurements of calcification

Ocean acidification (OA) is generally assumed to negatively impact calcification rates of marine organisms. At a local scale however, biological activity of macrophytes may generate pH fluctuations with rates of change that are orders of magnitude larger than the long-term trend predicted for the open ocean. These fluctuations may in turn impact benthic calcifiers in the vicinity. Combining laboratory, mesocosm and field studies, such interactions between OA, the brown alga Fucus vesiculosus, the sea grass Zostera marina and the blue mussel Mytilus edulis were investigated at spatial scales from decimetres to 100s of meters in the western Baltic. Macrophytes increased the overall mean pH of the habitat by up to 0.3 units relative to macrophyte- free, but otherwise similar, habitats and imposed diurnal pH fluctuations with amplitudes ranging from 0.3 to more than 1 pH unit. These amplitudes and their impact on mussel calcification tended to increase with increasing macrophyte biomass to bulk water ratio. At the laboratory and mesocosm scales, biogenic pH fluc- tuations allowed mussels to maintain calcification even under acidified conditions by shifting most of their calcification activity into the daytime when biogenic fluctuations caused by macrophyte activity offered temporal refuge from OA stress. In natural habitats with a low biomass to water body ratio, the impact of biogenic pH fluctuations on mean calcification rates of M. edulis was less pronounced. Thus, in dense algae or seagrass habitats, macrophytes may mitigate OA impact on mussel calcification by raising mean pH and providing temporal refuge from acidification stress.

Chemical analysis of explosive compounds in common dab (Limanda limanda) collected during the RV Heincke expedition HE622 from WW I + II munition dumping areas west of Sylt (NNW03L), north of Spiekeroog

This dataset documents field investigations regarding the release of legacy World War I and II munition explosive compounds into marine biota, focusing on munition dumping areas west of the island of Sylt, north of the island of Spiekeroog, and south of the reference area Borkum Riffgrund, North Sea. Flatfish Limanda limanda (common dab) was chosen as a sentinel species. Sampling was conducted during the HE622 cruise in June 2023 with the research vessel Heincke of the Alfred Wegener Institute (AWI). Fish were caught using bottom trawls deployed close to the borders of the dumping areas marked on the sea charts. Before dissection, captured fish were transferred to seawater tanks, and only live fish were taken for analysis. Each individual was measured, weighed, and after killing of the fish livers were assessed macroscopically. In addition, biometric factors were measured to determine condition factors as indicators of general health. Tissue samples of gills, liver, and muscle, as well as blood, bile, and urine, were taken, immediately frozen in liquid nitrogen, and stored at -20°C before chemical analysis. Sample processing in the laboratory followed established protocols. In brief, all samples were homogenized and then extracted using solid phase extraction (SPE). Bile, urine, and blood samples were treated with β-glucuronidase (Helix pomatia), followed by a liquid-liquid extraction step for blood and bile samples before SPE. All samples were analyzed by gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) for the explosive compound 2,4,6-trinitrotoluene (TNT), its metabolites 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT), and the explosive by-products 2,4-dinitrotoluene (2,4-DNT) and 1,3-dinitrobenzene (1,3-DNB). Additionally, liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS) was used to quantify the nitramine explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The dataset includes measured compound concentrations and associated sample metadata.

Mesocosm experiment on the influence of heatwave on plankton

In the context of global change, marine organisms are subjected not only to gradual changes in abiotic parameters, but also to an increasing number of extreme events, such as heatwaves. However, we still know little about the influence of heatwaves on the structure of marine communities, and experimental studies are needed to test the impact of heatwaves alone, and in combination with other environmental drivers. Here, we conducted a mesocosm experiment and applied an integrated multiple driver design to assess the potential impact of heatwaves under ambient and future environmental conditions on natural coastal plankton communities. To represent future environmental conditions, temperature and pH were manipulated based on the Representative Concentration Pathway 8.5 proposed by the IPCC for 2100, and dissolved N:P ratios were increased to simulate the conditions expected in European coastal zones. Throughout the experiment, we measured abiotic conditions as well as the abundance of bacterioplankton, phytoplankton, and microzooplankton.

Mercury and explosive compound 4-aminodinitrotoluene (4-ADNT) in dab (Limanda limanda) caught at munition dumping site Kolberger Heide in the Kiel Bight, Baltic Sea

Dumped munitions contain various harmful substances which can affect marine biota like fish. One of them is mercury (Hg), included in the common explosive primer. Another is 4-aminodinitrotoluene (4-ADNT), an explosive-metabolite. 251 individual dab (Limanda limanda L.) caught at the dump site Kolberger Heide a and nearby reference sites in 2017 and 2018 were analysed. The table contain individual data on Hg, 4-aminodinitrotoluene, age, length, weight, sex and condition factor.

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.

Bundesamt für Naturschutz: Seevogelerfassung Heringsmöwe Verbreitung (WMS)

Dieser Dienst enthält Informationen zur Populationsdichte der Heringsmöwe (Larus fuscus) in den deutschen Offshore-Gebieten basierend auf einem 10x10 km Raster (EU-GRID). Die Dichte [Individuen/km²] wird für jede Rasterzelle ermittelt, indem die Individuenzahl der Zählpunkte innerhalb der jeweiligen Rasterzelle addiert und durch die Summe des Aufwands an den Zählpunkten dividiert wird. Einzelne Layer zeigen unterteilt nach Jahreszeit (Artspezifisch nach Garthe S, Sonntag N, Schwemmer P, Dierschke V (2007) Estimation of seabirdnumbers in the German North Sea throughout the annual cycle and their biogeographic importance. Vogelwelt 128: 163–178) die Verbreitung der einzelnen Seevögel im jeweiligen Jahr. Datengrundlage sind die im Rahmen des Monitoringprogramms des BfN durchgeführten Seevogelerfassungen.

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