Monte Carlo Methods for Estimating Interfacial Free Energies and Line Tensions

Excess contributions to the free energy due to interfaces occur for many problems encountered in the statistical physics of condensed matter when coexistence between different phases is possible (e.g. wetting phenomena, nucleation, crystal growth, etc.). This article reviews two methods to estimate both interfacial free energies and line tensions by Monte Carlo simulations of simple models, (e.g. the Ising model, a symmetrical binary Lennard-Jones fluid exhibiting a miscibility gap, and a simple Lennard-Jones fluid). One method is based on thermodynamic integration. This method is useful to study flat and inclined interfaces for Ising lattices, allowing also the estimation of line tensions of three-phase contact lines, when the interfaces meet walls (where "surface fields" may act). A generalization to off-lattice systems is described as well. The second method is based on the sampling of the order parameter distribution of the system throughout the two-phase coexistence region of the model. Both the interface free energies of flat interfaces and of (spherical or cylindrical) droplets (or bubbles) can be estimated, including also systems with walls, where sphere-cap shaped wall-attached droplets occur. The curvature-dependence of the interfacial free energy is discussed, and estimates for the line tensions are compared to results from the thermodynamic integration method. Basic limitations of all these methods are critically discussed, and an outlook on other approaches is given

A risk-based approach to cumulative effect assessments for marine management

Marine ecosystems are increasingly threatened by the cumulative effects of multiple human pressures. Cumulative effect assessments (CEAs) are needed to inform environmental policy and guide ecosystem-based management. Yet, CEAs are inherently complex and seldom linked to real-world management processes. Therefore we propose entrenching CEAs in a risk management process, comprising the steps of risk identification, risk analysis and risk evaluation. We provide guidance to operationalize a risk-based approach to CEAs by describing for each step guiding principles and desired outcomes, scientific challenges and practical solutions. We reviewed the treatment of uncertainty in CEAs and the contribution of different tools and data sources to the implementation of a risk based approach to CEAs. We show that a risk-based approach to CEAs decreases complexity, allows for the transparent treatment of uncertainty and streamlines the uptake of scientific outcomes into the science-policy interface. Hence, its adoption can help bridging the gap between science and decision-making in ecosystem-based management

Annotated catalogue of the types of Triphoridae (Mollusca, Gastropoda) in the Museum für Naturkunde, Berlin, with lectotype designations

Triphoridae is a family of marine caenogastropods with worldwide distribution. Its maximum diversity is in the Indo-Pacific province, where it is among the five most species-rich families. Taxonomic knowledge is scant and complicated by the high diversity and intra-specific variability. Knowledge of type specimens of described taxa is the fundamental first step for a taxonomic revision of the family. The Museum für Naturkunde hosts one of the most significant triphorid collections, which includes material described by W. Dunker, L. Pfeiffer, J. Thiele and E. von Martens. Type material of 29 species is described and illustrated; where appropriate, lectotypes have been designated to stabilize nomenclature. The specimens of one species, Triforis delicatula Thiele, do not fully match the original description and we refrain from selecting a lectotype, although we profusely illustrate them. Although not type material, specimens of Triforis tricincta Dunker have been included in this work to contribute to the knowledge on Dunker’s species. For all species, the original descriptions in German or Latin are reported, with a full translation into English, and remarks have been added where appropriate

Record of the alien species Cerithium scabridum Philippi, 1848 (gastropoda, Cerithiidae) from Otranto, Southern Adriatic sea

A living population of the alien species Cerithium scabridum Philippi, 1848 was found in the harbour of Otranto (Lecce), south-western Adriatic Sea. Photographs of the living animal and observations on its behaviour are presented. This record extends the known distribution of this lessepsian immigrant into a new basin of the Mediterranean Sea

On the occurrence of Echinolittorina punctata (Gmelin, 1791) (Gastropoda: Littorinidae) in Puglia, South-Eastern Italy.

Evidence of live populations of Echinolittorina punctata on the Ionian coasts of Puglia, South-Eastern Italy, is given. These reports extend the known distribution of this species to a new area of the Mediterranean Basin and follow other records clearly describing an ongoing northwards range extension of the species

Holocene fish assemblages provide baseline data for the rapidly changing eastern Mediterranean

The eastern Mediterranean marine ecosystem is undergoing massive modification due to biological invasions, overfishing, habitat deterioration, and climate warming. Our ability to quantify these changes is severely hindered by the lack of an appropriate baseline; most ecological datasets date back a few decades only and show already strong signatures of impact. Surficial death assemblages (DAs) offer an alternative data source that provides baseline information on community structure and composition. In this study, we reconstruct the marine fish fauna of the southern shallow Israeli shelf before the opening of the Suez Canal based on fish otoliths. We quantify the age of the otolith DAs by radiocarbon dating, and describe its taxonomic composition, geographic affinity, and trophic structure. Additionally, we test by radiocarbon dating the hypothesis that Bregmaceros, a presumed Lessepsian invader with continuous presence in the Mediterranean throughout the late Cenozoic, is a relict species. The otolith DA dates back to the mid-Holocene because 75% of the dated otoliths of the native species are older than the opening of the Suez Canal in 1869, suggesting that the DA is a proper baseline for quantifying modern impacts. Consistently, 97% of the otoliths and 88% of the species we collected belong to native Mediterranean species. The native anchovy Engraulis encrasicolus dominates the DAs, although gobiids are the most diverse group (14 species, 28%). The DAs show similar trophic structure to present-day pristine Mediterranean coastal fish assemblages. Two non-indigenous species are recorded here for the first time in the Mediterranean Sea, Amblygobius albimaculatus and Callogobius sp., highlighting the importance of DAs for detecting non-indigenous species. Finally, Bregmaceros otoliths are modern, not supporting the previous hypothesis that the taxon is a Pleistocene relict. © The Author(s) 2020

Potential and limitations of applying the mean temperature approach to fossil otolith assemblages

Evaluation of the impact of climatic changes on the composition of fish assemblages requires quantitative measures that can be compared across space and time. In this respect, the mean temperature of the catch (MTC) approach has been proven to be a very useful tool for monitoring the effect of climate change on fisheries catch. Lack of baseline data and deep-time analogues, however, prevent a more comprehensive evaluation. In this study, we explore the applicability of the mean temperature approach to fossil fish faunas by using otolith assemblage data from the eastern Mediterranean and the northern Adriatic coastal environments corresponding to the last 8000 years (Holocene) and the interval 2.58–1.80 Ma B. P. (Early Pleistocene). The calculated mean temperatures of the otolith assemblage (MTO) range from 13.5 to 17.3 °C. This case study shows that the MTO can successfully capture compositional shifts in marine fish faunas based on variations in their climatic affinity driven by regional climate differences. However, the index is sensitive to methodological choices and thus requires standardized sampling. Even though theoretical and methodological issues prevent direct comparisons between MTO and MTC values, the MTO offers a useful quantitative proxy for reconstructing spatial and temporal trends in the biogeographic affinity of fossil otolith assemblages. © 2022, The Author(s)

The taphonomic clock in fish otoliths

Paleobiological and paleoecological interpretations rely on constraining the temporal resolution of the fossil record. The taphonomic clock, that is, a correlation between the alteration of skeletal material and its age, is an approach for quantifying time-averaging scales. We test the taphonomic clock hypothesis for marine demersal and pelagic fish otoliths from a 10-40 m depth transect on the Mediterranean siliciclastic Israeli shelf by radiocarbon dating and taphonomic scoring. Otolith ages span the last ∼8000 yr, with considerable variation in median and range along the transect. Severely altered otoliths, contrary to pristine otoliths, are likely to be older than 1000 yr. For pelagic fish otoliths, at 30 m depth, taphonomic degradation correlates positively with postmortem age. In contrast, no correlation occurs for demersal fishes at 10 and 30 m depth, mostly because of the paucity of very young pristine (<150 yr) otoliths, possibly due to a drop in production over the last few centuries. Contrary to molluscan and brachiopod shells, young otoliths at these depths are little affected and do not show a broad spectrum of taphonomic damage, because those that derive from predation are excreted in calcium- and phosphate-rich feces forming an insoluble crystallic matrix that increases their preservation potential. At 40 m depth, all dated otoliths are very young but rather damaged because of locally chemically aggressive sediments, thus showing no correlation between taphonomic grade and postmortem age. Our results show that local conditions and the target species population dynamics must be considered when testing the taphonomic clock hypothesis. © The Author(s), 2021. Published by Cambridge University Press on behalf of The Paleontological Society

Radiocarbon dating supports bivalve-fish age coupling along a bathymetric gradient in high-resolution paleoenvironmental studies

Studies of paleocommunities and trophic webs assume that multispecies assemblages consist of species that coexisted in the same habitat over the duration of time averaging. However, even species with similar durability can differ in age within a single fossil assemblage. Here, we tested whether skeletal remains of different phyla and trophic guilds, the most abundant infaunal bivalve shells and nektobenthic fish otoliths, differed in radiocarbon age in surficial sediments along a depth gradient from 10 to 40 m on the warm-temperate Israeli shelf, and we modeled their dynamics of taphonomic loss. We found that, in spite of the higher potential of fishes for out-of-habitat transport after death, differences in age structure within depths were smaller by almost an order of magnitude than differences between depths. Shell and otolith assemblages underwent depth-specific burial pathways independent of taxon identity, generating death assemblages with comparable time averaging, and supporting the assumption of temporal and spatial co-occurrence of mollusks and fishes. © 2020 The Authors. Gold Open Access