Seasonal variability of meio- and macrobenthic standing stocks and diversity in an Arctic fjord (Adventfjorden, Spitsbergen)

Strong environmental seasonality is a basic feature of the Arctic system, still there are few published records of the seasonal variability of the Arctic marine biota. This study examined the year-round seasonal changes of soft bottom macro- and meiobenthic standing stocks and diversity on a station located in an Arctic fjord (Adventfjorden, Spitsbergen). The seasonality observed in benthic biota was related to the pelagic processes, primarily the seasonal fluxes of organic and inorganic particles. The highest abundance, biomass and richness of benthic fauna occurred in the spring after the phytoplankton bloom. During the summer, when a high load of glacial mineral material was transported to the fiord, the number of both meio- and macrobenthic individuals decreased remarkably. The strong inorganic sedimentation in summer was accompanied by a decline in macrobenthic species richness, but had no effects on evenness. Redundancy analysis (RDA) pointed to granulometric composition of sediments (depended on mineral sedimentation) and organic fluxes as factors best related to meio- and macrobenthic taxonomic composition, but no clear seasonal trend could be observed on the nMDS plots based on meiobenthic higher taxa or macrobenthic species abundances in the samples. This study addresses the possible effects of changes in the winter ice cover on the fjordic benthic systems because it was performed in a year with no ice cover on the fjord

The Crowdsourced Replication Initiative: Investigating Immigration and Social Policy Preferences. Executive Report.

In an era of mass migration, social scientists, populist parties and social movements raise concerns over the future of immigration-destination societies. What impacts does this have on policy and social solidarity? Comparative cross-national research, relying mostly on secondary data, has findings in different directions. There is a threat of selective model reporting and lack of replicability. The heterogeneity of countries obscures attempts to clearly define data-generating models. P-hacking and HARKing lurk among standard research practices in this area.This project employs crowdsourcing to address these issues. It draws on replication, deliberation, meta-analysis and harnessing the power of many minds at once. The Crowdsourced Replication Initiative carries two main goals, (a) to better investigate the linkage between immigration and social policy preferences across countries, and (b) to develop crowdsourcing as a social science method. The Executive Report provides short reviews of the area of social policy preferences and immigration, and the methods and impetus behind crowdsourcing plus a description of the entire project. Three main areas of findings will appear in three papers, that are registered as PAPs or in process

The amphipod scavenging guild in two Arctic fjords : seasonal variations, abundance and trophic interactions

Scavenging amphipods are important for the circulation and dispersal of organic material in the marine environment. Despite their dominance in the scavenging guild and importance in the food web, little is known about Arctic amphipods and their feeding preferences. We studied the amphipod scavenging guild using baited traps for one full year to increase our understanding of its seasonal variations. Two Arctic fjords with contrasting hydrographical conditions were studied: Adventfjorden, which is influenced by Atlantic water inflow, and Rijpfjorden, which is dominated by cold Arctic water masses. The species composition clearly differed between the 2 fjords. Onisimus caricus, followed by Anonyx laticoxae, were the dominant species in Adventfjorden. In Rijpfjorden, the species diversity was higher, particularly for Anonyx spp. In both fjords, a clear depth zonation in species distribution was detected, with a seasonal dynamic in species composition. A seasonal pattern in catch sizes was observed in both fjords. The timing of this pattern varied, likely because of the climatic differences between the fjords. Lipid content, lipid classes and fatty acid composition were analyzed for A. nugax, O. caricus, O. litoralis, O. nanseni and O. glacialis, and stable isotopes were also analyzed for the all these species except O. glacialis. A clear difference in the fatty acid and stable isotope composition was found among species. O. glacialis and O. litoralis were primarily omnivorous-herbivorous, while the other species were predominantly carnivorous. O. nanseni and A. nugax preyed extensively on calanoid copepods (Calanus spp.) whereas O. caricus did not

Potential misidentifications of two climate indicator species of the marine arctic ecosystem: Calanus glacialis and C. finmarchicus

Calanoid copepods of the genus Calanus represent an important, nutrient-rich food source for a multitude of Arctic marine organisms. Although morphologically very similar, their life histories and ecological roles differ. Because the distribution of Calanus glacialis and C. finmarchicus corresponds to Arctic and Atlantic water masses, respectively, they are regularly used as climate indicators. A correct identification of these species is therefore necessary in many ecological, environmental and climatological studies. In this study, we aimed at validating the traditionally used morphological characteristics (combining prosome length and copepodite stage) for separation of species of Calanus by using molecular tools (PCR–RFLP of the 16S mtDNA). A total of 418 specimens of copepodite stages CIV, CV and CVI(af) from three Arctic fjords have been identified both morphologically and genetically. We find that the morphological identification systematically overestimates the abundance of C. finmarchicus at the expense of C. glacialis. Hence, parts of the C. glacialis populations are found to be structurally smaller and the within population size range thus larger than previously assumed. Consequently, using the traditional morphological species delimitation poses a serious problem in the use of these two species as indicators of Atlantic versus Arctic water masses and thus as climatic indicators. Furthermore, it obscures our understanding of the life history differences between the two species and of their relative importance as food for a number of ecologically and economically important species in the Arctic

The Crowdsourced Replication Initiative: Investigating Immigration and Social Policy Preferences. Executive Report

Breznau N, Rinke EM, Wuttke A, et al. The Crowdsourced Replication Initiative: Investigating Immigration and Social Policy Preferences. Executive Report. 2019

Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty.

This study explores how researchers' analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers' expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team's workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers' results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings

How Many Replicators Does It Take to Achieve Reliability? Investigating Researcher Variability in a Crowdsourced Replication

The paper reports findings from a crowdsourced replication. Eighty-four replicator teams attempted to verify results reported in an original study by running the same models with the same data. The replication involved an experimental condition. A “transparent” group received the original study and code, and an “opaque” group received the same underlying study but with only a methods section and description of the regression coefficients without size or significance, and no code. The transparent group mostly verified the original study (95.5%), while the opaque group had less success (89.4%). Qualitative investigation of the replicators’ workflows reveals many causes of non-verification. Two categories of these causes are hypothesized, routine and non-routine. After correcting non-routine errors in the research process to ensure that the results reflect a level of quality that should be present in ‘real-world’ research, the rate of verification was 96.1 in the transparent group and 92.4 in the opaque group. Two conclusions follow: (1) Although high, the verification rate suggests that it would take a minimum of three replicators per study to achieve replication reliability of at least 95 confidence assuming ecological validity in this controlled setting, and (2) like any type of scientific research, replication is prone to errors that derive from routine and undeliberate actions in the research process. The latter suggests that idiosyncratic researcher variability might provide a key to understanding part of the “reliability crisis” in social and behavioral science and is a reminder of the importance of transparent and well documented workflows