How can Sentinel‐2 contribute to seagrass mapping in shallow, turbid Baltic Sea waters?

Seagrass meadows are one of the most important benthic habitats in the Baltic Sea. Nevertheless, spatially continuous mapping data of Zostera marina, the predominant seagrass species in the Baltic Sea, are lacking in the shallow coastal waters. Sentinel-2 turned out to be valuable for mapping coastal benthic habitats in clear waters, whereas knowledge in turbid waters is rare. Here, we transfer a clear water mapping approach to turbid waters to assess how Sentinel-2 can contribute to seagrass mapping in the Western Baltic Sea. Sentinel-2 data were atmospherically corrected using ACOLITE and subsequently corrected for water column effects. To generate a data basis for training and validating random forest classification models, we developed an upscaling approach using video transect data and aerial imagery. We were able to map five coastal benthic habitats: bare sand (25 km²), sand dominated (16 km²), seagrass dominated (7 km²), dense seagrass (25 km²) and mixed substrates with red/ brown algae (3.5 km²) in a study area along the northern German coastline. Validation with independent data pointed out that water column correction does not significantly improve classification results compared to solely atmospherically corrected data (balanced overall accuracies ˜0.92). Within optically shallow waters (0–4 m), per class and overall balanced accuracies (>0.82) differed marginally depending on the water depth. Overall balanced accuracy became worse (<0.8) approaching the border to optically deep water (˜ 5 m). The spatial resolution of Sentinel-2 (10–20 m) allowed delineating detailed spatial patterns of seagrass habitats, which may serve as a basis to retrieve spatially continuous data for ecologically relevant metrics such as patchiness

Discovery and quantification of a widespread methane ebullition event in a coastal inlet (Baltic Sea) using a novel sonar strategy

How much of the greenhouse gas methane is transported from the seafloor to the atmosphere is unclear. Here, we present data describing an extensive ebullition event that occurred in Eckernförde Bay, a shallow gas-hosting coastal inlet in the Baltic Sea, in the fall of 2014. A weak storm induced hydrostatic pressure fluctuations that in turn stimulated gas ebullition from the seabed. In a finely tuned sonar survey of the bay, we obtained a hydroacoustic dataset with exceptionally high sensitivity for bubble detection. This allowed us to identify 2849 bubble seeps rising within 28 h from the seafloor across the 90 km² study site. Based on our calculations, the estimated bubble-driven episodic methane flux from the seafloor across the bay is 1,900 μMol m-2 d-1. Our study demonstrates that storm-associated fluctuations of hydrostatic pressure induce bulk gas-driven ebullitions. Given the extensive occurrence of shallow gas-hosting sediments in coastal seas, similar ebullition events probably take place in many parts of the Western Baltic Sea. However, these are likely to be missed during field investigations, due to the lack of high-quality data acquisition during storms, such that atmospheric inputs of marine-derived methane will be highly underestimated

Measurement of Seafloor Acoustic Backscatter Angular Dependence at 150 kHz Using a Multibeam Echosounder

Acoustic seafloor measurements with multibeam echosounders (MBESs) are currently often used for submarine habitat mapping, but the MBESs are usually not acoustically calibrated for backscattering strength (BBS) and cannot be used to infer absolute seafloor angular dependence. We present a study outlining the calibration and showing absolute backscattering strength values measured at a frequency of 150 kHz at around 10–20 m water depth. After recording bathymetry, the co-registered backscattering strength was corrected for true incidence and footprint reverberation area on a rough and tilted seafloor. Finally, absolute backscattering strength angular response curves (ARCs) for several seafloor types were constructed after applying sonar backscattering strength calibration and specific water column absorption for 150 kHz correction. Thus, we inferred specific 150 kHz angular backscattering responses that can discriminate among very fine sand, sandy gravel, and gravelly sand, as well as between bare boulders and boulders partially overgrown by red algae, which was validated by video ground-truthing. In addition, we provide backscatter mosaics using our algorithm (BBS-Coder) to correct the angle varying gain (AVG). The results of the work are compared and discussed with the published results of BBS measurements in the 100–400 kHz frequency range. The presented results are valuable in extending the very sparse angular response curves gathered so far and could contribute to a better understanding of the dependence of backscattering on the type of bottom habitat and improve their acoustic classificatio

Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10-30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of similar to 2.0-2.5 degrees C, during daily fluctuations that often exceeded 15 degrees-20 degrees C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on 'habitat-level' measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially-and temporally-explicit field observations of body temperature

Machbarkeitsstudie Kinderbetreuungsscheck: Entwicklung von Modellen eines Kinderbetreuungsschecks und Analyse der Auswirkungen; Rohbericht. Bd. 1, Ergebnisbericht

Im Rahmen zweier Studien zur Teilzeitbetreuung von Kindern in Österreich wurde im Mai 95 die Idee eines Betreuungsschecks - als unspezifische Maßnahme zur Unterstützung von Teilzeitbetreuung von Kindern - entwickelt. Mit diesem Modell kann Teilzeitbetreuung eingekauft oder selbst wahrgenommen werden. Über den Aspekt der Teilzeitbetreuung hinaus werden folgende Anliegen diskutiert: Bekämpfung von Armut, die durch Kinder entsteht, Aufbau eines Leistungsausgleichs im Konzept des 3-Generationenvertrages, Einführung einer Grundsicherung für jede Person, Neubewertung von Arbeit sowie Sicherung der Zukunft des Humanvermögens. Die Beauftragung zur Durchführung der Machbarkeitsstudie zum Betreuungsscheck erfolgte durch das Bundesministerium für Umwelt, Jugend und Familie aufgrund eines einstimmigen Beschlusses des familienpolitischen Beirates. Das Projekt verfolgt das Ziel, die Auswirkungen der neuen sozialpolitischen Maßnahme "Kinderbetreuungsscheck" unter verschiedenen Gesichtspunkten und auf mehreren Ebenen abzuschätzen und allfällig erforderliche Bedingungen und Modifikationen für die Machbarkeit aufzuzeigen. Der Rohbericht wird in zwei Bänden vorgelegt. Band 1 "Ergebnisbericht" stellt die erarbeiteten Ergebnisse (Kapitel 1-6) und deren folgernde Zusammenfassung (Kapitel 7) in verdichteter Form dar. Der Band 2 "Grundlagen" beinhaltet meist eine ausführlichere Darstellung zum Thema und die Beilagen. Die sechs Kapitel entsprechen jenen im Band 1 und bilden die Grundlage für diese

Reseñas

LANTBERT VON DEUTZ, Vita Heriberti, Maracula Heriberti, Gedichte, Liturgische Text, ed. B. VOGEL. THOMAS AQUINAS, Political Writings, trad. R. W. DYSON. G. FIORANVANTI (ed), Anonymi Quaestiones Super Octavum Librum Physicorum. D. PERLER, Théories de l’intentionnalité au moyen âge. J. PETERSOHN, Kaiserlicher Gesandter und Kurienbischof. Andreas Jamometic am Hof Papst Sixtus IV. Aufschlüsse aus neuen Quellen. M. LUTZ-BACHMANN / A. FIDORA / A. NIEDERBERGER (ed), Metaphysics in the Twelfth Century. On the Relationship among Philosophy, Science and Theologie. J. MIETHKE, Studieren am mittelalterlichen Universitäten. Chancen und Risiken. Gesammelte Aufstätze. M. LENTZ, Konflikt, Ehre, Ordnung. Untersuchungen zu den Schmähbriefen und Schandbildern des späten Mittelalters und der frühen Neuzeit. THERESE FUHRER, Augustinus, ed. M. HOSE. ANNEGRET HOLTMANN, Juden in der Grafschaft Burgund im Mittelalter. M. C. HÄRTEL, Die spätgotische Pfarr- und Stiftskirche St. Andreas in Hildesheim. B. BRUNNING / J. L. CONG QUY (comp), Mélanges offerts à T. J. Van Bavel à l’occasion de son 80e anniversaire. Augustiniana 2004. RAMON LLULL, Arte Breve. G. SCHMITZ, De presbiteris criminosis. Ein Memorandum Erzbischof Hinkmars von Reims. E. HLAWITSCHKA, Konradiner-Genealogie, unstatthafte Verwandtenehen und spätottonisch-frühsalische Thronbesetzungspraxis. S. WEISS, Rechnungswesen und Buchhaltung des Avignoneser papsttums (1316-1378). Eine Quellenkunde. M. M. TISCHLER, Einharts Vita Karoli. Studien zur Entstehung, Überlieferung und Rezeption. H. HOPING, Einführung in die Christologie. K. KREMER, Praegustatio naturalis sapientiae. Gott suchen mit Nikolaus von Kues. M. KAUFHOLD (ed), Politische Reflexion in der Welt des späten Mittelalters. M. LUTZ-BACHMANN / A. FIDORA (eds), Juden, Christen und Muslime. Religions Dialogue im Mittelalter. O. LANGER, Christliche Mystik im Mittelalter. Mystik und Rationalisierung

Ocean weather, biological rates, and unexplained global ecological patterns.

As on land, oceans exhibit high temporal and spatial temperature variation. This ocean weather contributes to the physiological and ecological processes that ultimately determine the patterns of species distribution and abundance, yet is often unrecognized, especially in tropical oceans. Here, we tested the paradigm of temperature stability in shallow waters (&lt;12.5 m) across different zones of latitude. We collated hundreds of in situ, high temporal-frequency ocean temperature time series globally to produce an intuitive measure of temperature variability, ranging in scale from quarter-diurnal to annual time spans. To estimate organismal sensitivity of ectotherms (i.e. microbes, algae, and animals whose body temperatures depend upon ocean temperature), we computed the corresponding range of biological rates (such as metabolic rate or photosynthesis) for each time span, assuming an exponential relationship. We found that subtropical regions had the broadest temperature ranges at time spans equal to or shorter than a month, while temperate and tropical systems both exhibited narrow (i.e. stable) short-term temperature range estimates. However, temperature-dependent biological rates in tropical regions displayed greater ranges than in temperate systems. Hence, our results suggest that tropical ectotherms may be relatively more sensitive to short-term thermal variability. We also highlight previously unexplained macroecological patterns that may be underpinned by short-term temperature variability

Effects of Elevated Temperature and Carbon Dioxide on the Growth and Survival of Larvae and Juveniles of Three Species of Northwest Atlantic Bivalves

Rising CO2 concentrations and water temperatures this century are likely to have transformative effects on many coastal marine organisms. Here, we compared the responses of two life history stages (larval, juvenile) of three species of calcifying bivalves (Mercenaria mercenaria, Crassostrea virginica, and Argopecten irradians) to temperatures (24 and 28°C) and CO2 concentrations (∼250, 390, and 750 ppm) representative of past, present, and future summer conditions in temperate estuaries. Results demonstrated that increases in temperature and CO2 each significantly depressed survival, development, growth, and lipid synthesis of M. mercenaria and A. irradians larvae and that the effects were additive. Juvenile M. mercenaria and A. irradians were negatively impacted by higher temperatures while C. virginica juveniles were not. C. virginica and A. irradians juveniles were negatively affected by higher CO2 concentrations, while M. mercenaria was not. Larvae were substantially more vulnerable to elevated CO2 than juvenile stages. These findings suggest that current and future increases in temperature and CO2 are likely to have negative consequences for coastal bivalve populations

Genetic Structure Among 50 Species of the Northeastern Pacific Rocky Intertidal Community

Comparing many species' population genetic patterns across the same seascape can identify species with different levels of structure, and suggest hypotheses about the processes that cause such variation for species in the same ecosystem. This comparative approach helps focus on geographic barriers and selective or demographic processes that define genetic connectivity on an ecosystem scale, the understanding of which is particularly important for large-scale management efforts. Moreover, a multispecies dataset has great statistical advantages over single-species studies, lending explanatory power in an effort to uncover the mechanisms driving population structure. Here, we analyze a 50-species dataset of Pacific nearshore invertebrates with the aim of discovering the most influential structuring factors along the Pacific coast of North America. We collected cytochrome c oxidase I (COI) mtDNA data from populations of 34 species of marine invertebrates sampled coarsely at four coastal locations in California, Oregon, and Alaska, and added published data from 16 additional species. All nine species with non-pelagic development have strong genetic structure. For the 41 species with pelagic development, 13 show significant genetic differentiation, nine of which show striking FST levels of 0.1–0.6. Finer scale geographic investigations show unexpected regional patterns of genetic change near Cape Mendocino in northern California for five of the six species tested. The region between Oregon and Alaska is a second focus of intraspecific genetic change, showing differentiation in half the species tested. Across regions, strong genetic subdivision occurs more often than expected in mid-to-high intertidal species, a result that may reflect reduced gene flow due to natural selection along coastal environmental gradients. Finally, the results highlight the importance of making primary research accessible to policymakers, as unexpected barriers to marine dispersal break the coast into separate demographic zones that may require their own management plans