Biometry and taxonomy of Adriatic <i>Ammonia</i> species from Bellaria–Igea Marina (Italy)

Living Ammonia species and an inventory of dead assemblages from Adriatic subtidal, nearshore environments were investigated at four stations off Bellaria, Italy. Ammonia falsobeccarii, Ammonia parkinsoniana, Ammonia tepida, and Ammonia veneta were recognized in the living (rose-bengal-stained) fauna, and Ammonia bellaria n. sp. is described herein for the first time. Ammonia beccarii was only found in the dead assemblage. The biometry of 368 living individuals was analysed by using light microscopic and scanning electron microscopic images of three aspects. A total of 15 numerical and 8 qualitative parameters were measured and assessed, 5 of which were recognized to be prone to a certain subjectivity of the observer. The accuracy of numerical data as revealed by the mean residuals of parallel measurements by different observers ranged from 0.5 % to 5.5 %. The results indicated a high degree of intraspecific variability. The test sizes of the individual species were log-normally distributed and varied among the stations. Parameters not related to the growth of the individuals, i.e. flatness of the tests, dimensions of the second-youngest chamber, proloculus, umbilical and pore diameter, sinistral–dextral coiling, and umbilical boss size, were recognized as being species-distinctive in combination. They may well supplement qualitative criteria that were commonly used for species discrimination such as a lobate outline, a subacute or rounded peripheral margin, or the degree of ornamentation on the spiral and umbilical sides. The averages of the measured parameters were often lower than the range of previously published values, mainly because the latter were retrieved from a few adult specimens and not from the whole assemblage as in the present approach. We conclude that the unprecedented high proportions of Ammonia beccarii in the northern Adriatic may well be artificial. A robust species identification without genetic analyses is possible by considering designated biometric parameters. This approach is also applicable to earlier literature data, and their re-assessment is critical for a correct denomination of recent genotypes.

Insolation-paced sea level and sediment flux during the early Pleistocene in Southeast Asia

Global marine archives from the early Pleistocene indicate that glacial-interglacial cycles, and their corresponding sea-level cycles, have predominantly a periodicity of ~ 41 kyrs driven by Earth’s obliquity. Here, we present a clastic shallow-marine record from the early Pleistocene in Southeast Asia (Cholan Formation, Taiwan). The studied strata comprise stacked cyclic successions deposited in offshore to nearshore environments in the paleo-Taiwan Strait. The stratigraphy was compared to both a δ18O isotope record of benthic foraminifera and orbital parameters driving insolation at the time of deposition. Analyses indicate a strong correlation between depositional cycles and Northern Hemisphere summer insolation, which is precession-dominated with an obliquity component. Our results represent geological evidence of precession-dominated sea-level fluctuations during the early Pleistocene, independent of a global ice-volume proxy. Preservation of this signal is possible due to the high-accommodation creation and high-sedimentation rate in the basin enhancing the completeness of the stratigraphic record.

Phytoplankton Time-Series in a LTER Site of the Adriatic Sea: Methodological Approach to Decipher Community Structure and Indicative Taxa

In the shallow and landlocked northeast Adriatic Sea, environmental factors have changed in recent decades. Their influence on seasonal and inter-annual variability of phytoplankton has been documented in the recent literature. Here, we decipher the long-term variability of phytoplankton phenology at a Long-Term Ecological Research site (Gulf of Trieste, Slovenia). Structural changes in the phytoplankton community (period 2005–2017) were analysed using a multivariate protocol based on Bayesian clustering. The protocol was modified from the literature to fit the needs of the study, using correspondence analysis and k-means clustering. A novel index for ordination and selection of taxa based on frequency and evenness was developed. The Total Inertia analysis showed that this index better preserved the available information. Typical seasonal assemblages were highlighted by applying the Indicative Value index in conjunction with likelihood ratio values. We obtained a rough picture of the seasonal separation of the diatom-dominated community from the mixed community and a refined picture of the phenology of the assemblages and bloom events. The spring diatom peak proved to be inconstant and short-lived, while the autumn bloom was generally long and diverse. As expected for nearshore environments, the average life span of the assemblages was found to be short-periodic (2–4 months). The second part of the year and the last part of the series were more prone to changes in terms of typical assemblages.

Tropical Oil Pollution Investigations in Coastal Systems [TROPICS]: A 32-year Review of Response and Recovery

ABSTRACT In 1984, the Tropical Oil Pollution Investigations in Coastal Systems (TROPICS) experiment began in Bahia Almirante on the Caribbean coast of Panama. This study sought to compare the impacts of a severe, but realistic spill of untreated crude oil versus chemically treated (dispersed) crude oil on tropical marine reef, sea-grass, and mangrove ecosystems. The aim of the study was to identify and evaluate the environmental trade-offs of dispersant use in tropical marine and subtidal systems. As a result of continuing research at the site, the study became one of the most comprehensive field experiments examining the long-term impacts of oil and dispersed oil exposures in nearshore tropical communities. Consequently, TROPICS has been the foundational and seminal field study which served as the historical antecedent for Net Environmental Benefit Analysis (NEBA), as well as the basis for follow-on Spill Impact Mitigation Analysis (SIMA) and Comparative Risk Analysis (CRA) for oil spill planning, preparation, and response. From the initial experiment in 1984, through three decades of study and data collection visits, the coral reef, seagrass, and mangrove communities have exhibited significantly different damage and recovery regimes, depending on whether the sites were exposed to non-treated crude oil or dispersed crude oil. While this study does not definitively determine whether or not dispersants should be applied in tropical nearshore environments, it is illustrative of the environmental and ecosystem trade-offs between surface oil impacts to the shoreline, compared to water column exposure from chemically dispersed oil. This paper provides an overview of the results and observations reported in numerous previous TROPICS publications, as a progression of damage and recovery over time. With this perspective, planners and responders can use this study to predict what damages/recoveries may be expected from an oil spill incident in this environment. The results of the TROPICS experiment are examined within the context of this recent parallel research from the perspective of ongoing implications for oil spill preparedness and response.

High Resolution Turbidity Modelling in Arctic Nearshore Environments

&lt;p&gt;The Arctic is directly impacted by climate change. The increase in air temperature drives the thawing of permafrost and an increase in coastal erosion and river discharge. This leads to a greater input of sediment and organic matter into coastal waters, which substantially impacts the ecosystems, the subsistence economy of the local population, and the climate because of the transformation of organic matter into greenhouse gases. Yet, the patterns of sediment dispersal in Arctic nearshore zones and their role in the Carbon cycle are not well known due to difficult accessibility and challenging weather conditions. In this study we present the first multi-sensor turbidtiy- reflectance relationship that was specifically calibrated for Arctic nearshore environments. Field data was collected during summer seasons 2018 and 2019 in the inner shelf waters of the Canadian Beaufort Sea close to Herschel Island Qikiqtaruk. The turbidity-reflectance relationship was calibrated to mid to high spatial resolution sensors which are used in ocean color remote sensing, including Landsat 8, Sentinel 2, and Sentinel 3, using the relative spectral response functions. The results for Landsat 8 and Sentinel 2 are very promising and showcase the possibility to resolve sediment accumulations, sediment pathways and filaments at higher detail than before. Both sensors are able to resolve high turbidity close to the coast with values comparable to our field measurements. Sentinel 3, on the other hand, is too coarse to resolve these features but provides great applicability due to its high temporal resolution. The transferability&amp;#160; of these relationships to nearshore environments outside the Canadian Beaufort Sea has to be tested in the future with the potential to map the sediment dispersal in nearshore environments at a circum- Arctic scale.&lt;/p&gt;

Susan Lynn Williams: the Life of an Exceptional Scholar, Leader, and Friend (1951–2018)

Susan Lynn Williams (1951–2018) was an exceptional marine ecologist whose research focused broadly on the ecology of benthic nearshore environments dominated by seagrasses, seaweeds, and coral reefs. She took an empirical approach founded in techniques of physiological ecology. Susan was committed to applying her research results to ocean management through outreach to decision-makers and resource managers. Susan’s career included research throughout the USA in tropical, temperate, and polar regions, but she specialized in tropical marine ecology. Susan’s scholarship, leadership, and friendship touched many people, leading to this multi-authored paper. Susan’s scholarship was multi-faceted, and she excelled in scientific discovery, integration of scientific results, application of science for conservation, and teaching, especially as a mentor to undergraduate and graduate students and postdoctoral scholars. Susan served in a variety of leadership positions throughout her career. She embodied all facets of leadership; leading by example, listening to others, committing to the “long haul,” maintaining trust, and creating a platform for all to shine. Susan was an important role model for women in science. Susan was also a loyal friend, maintaining friendships for many decades. Susan loved cooking and entertaining with friends. This paper provides an overview of the accomplishments of Susan in the broad categories of scholarship, leadership, and friendship.