On losing and recovering fisheries and marine science data

Large sums are spent annually collecting and, increasingly, electronically encoding field data, making them widely accessible. Earlier data were recorded on paper, and archived at a few institutions, which eventually discard them. Data recovery and distribution is a valuable contribution to science, as it counters the ‘shifting baseline’ syndrome and ensures long-term returns on funds society invested in data gathering. Data recovery need not be expensive. We present the data recovery from the Guinean Trawling Survey, conducted in the early 1960s off West Africa, which cost 0.2% of initial survey costs. Research and graduate training institutions, as well as funding agencies should make digital data globally available as part of their deliverables

Differential Influence of Relative Poverty on Preferences for Ecosystem Services: Evidence from Rural Indonesia

Ecosystem services generate benefits that enter human consumption either directly or indirectly via their contribution to human production activities. In this contribution, we provide evidence that (i) the demand of peasants for ecosystem services in rural Indonesia depends on relative poverty; and that (ii) the type of reaction to poverty depends on the specific relation of the ecosystem services to peasant production and consumption. In early 2005 a representative choice experiment study was conducted in the Lore Lindu area in Central Sulawesi, Indonesia, to quantify regional economic preferences (marginal willingessto- pay: MWTP) for four different ecosystem services (n=249; rattan and water availability, shading in cacao agroforestry, population size of the endemic forest dwelling dwarf buffalo "anoa"). Relative poverty was calculated with the 2005 data using a 0,1-normally distributed relative poverty index developed from a socio-demographic household survey administered to the same sample in 2004. For shading in cocoa, a linearly decreasing trend is observed indicating a stronger preference for "sun-grown" cocoa in the less poor farmers indicating a constant poverty elasticity of WTP. The empirical poverty elasticity for anoa supports its luxury good characteristic only in part. For rattan and water, we find an inverted U-shape relation between MWTP for ecosystem services and relative poverty - probably due to serious restrictions in the ability to pay in the poorest households and a smaller resource dependency in the less poor households. In sum, the relationship between relative poverty and MWTP for ecosystem services appears more complex than classical micro-economic theory admits.Relative poverty, Choice experiment, ecosystem services, environmental valuation, Resource /Energy Economics and Policy, Q21, Q51, Q56, Q57,

Driver fatigue and performance decrements over time-on-task: Effects and mitigation

Road crashes are a leading cause of death by injury globally (WHO, 2018), with fatigue estimated to contribute to 17% of fatal crashes (Tefft, 2012; TfNSW, 2017). A century of research has advanced our knowledge regarding the causes and effects of fatigue, but much remains unknown. In particular, while there is evidence that both heightened sleep-need and characteristics of the driving task can give rise to fatigue, the relative and combined effects of these factors are not sufficiently understood. Also, while several potential task-based fatigue interventions have been suggested, the effectiveness of these potential interventions is not well established. The present research is comprised of three empirical, driving simulator-based studies that aim to enhance our current understanding of the causes and possible mitigators of driver fatigue. The first study aimed to determine the contributions of time-on-task and sleep restriction, individually and combined, on the development of driver fatigue and performance impairment, and to investigate the potentially protective effects of a simple task modification. Sixty participants drove a simulated, monotonous route for 2 hours, under conditions of either prior sleep restriction or no sleep restriction, and with either normal speed limit signs or signs that required calculation of a mathematical problem, which has previously been shown to protect performance (Dunn & Williamson, 2012). Results clearly demonstrate that both sleep restriction and time-on-task contribute independently to driver fatigue, but there was some indication that sleep-restricted drivers could initially protect their performance, perhaps through the exertion of greater effort. The speed sign manipulation failed to show any protective effects. The second study was designed to further examine the effect of task-factors on driver state and performance over time-on-task. Exposure to a secondary cognitive task has been found to improve driving performance during the period of exposure, but the effects of this intervention over the duration of a drive has received limited attention. This study specifically investigated whether repeated exposures to a secondary task can overcome the degradation of performance and subjective state that occurs over time-on-task, whether any such benefits are dependent on the cognitive workload imposed by the task, and whether these beneficial effects might be attributable to increased effort. This study (N = 17, fully within participants design) employed a secondary cognitive task commonly found to elicit temporally limited beneficial effects in driving performance (n-back task), presenting it three times during an otherwise monotonous 90-minute simulated drive. Each participant performed three drives, one in each of three conditions, with order of condition counterbalanced between participants. The three conditions involved either three periods of 2-back (higher cognitive workload), three periods of 0-back (lower cognitive workload), or no n-back task (control). Results demonstrated that the 2-back condition marginally improved driving performance during exposure but neither condition reduced the degradation of performance or subjective state over time-on-task. The third study built upon study two by exploring whether increasing the frequency of secondary-task exposures would result in reduced performance decrements over time and also by comparing the effect of secondary-task exposure to the effect of taking breaks from driving, which is currently the typical advice provided to drivers to counteract fatigue and performance decrements. This study involved ninety-two participants driving a simulated, monotonous route for 90 minutes in one of six conditions: Driving only (control); infrequent 2-back exposure (three exposures, as per study 2); frequent 2-back exposure (five exposures); continuous 2-back exposure throughout the drive; infrequent breaks (three breaks); or frequent breaks (five breaks). Results indicate that infrequent exposure to a secondary task sustained driving performance over 90-minutes of time-on-task, which is inconsistent with the findings of study 2. Contrary to expectations, frequent secondary-task exposure was less beneficial than infrequent exposure, providing no benefit over the control condition. Continuous secondary-task exposure was detrimental to performance over time-on-task. The provision of breaks from driving also sustained driving performance over time-on-task, with more frequent breaks providing marginally greater benefit than less frequent breaks. Providing participants with breaks from driving was also beneficial for subjective states, measured as sleepiness, fatigue and effort. Results also confirmed that performance improvements in the secondary-task conditions were not solely a result of increased effort. These studies demonstrate that continuous time-on-task driving in highway-like conditions has a robust fatiguing effect. This effect is independent of, but exacerbated by, receiving insufficient sleep, highlighting the importance of taking continuous operating time into consideration, even in the context of seemingly simple tasks and when drivers are well-slept. Additionally, these studies demonstrate that repeated exposure to a secondary task might be an effective intervention for sustaining performance during monotonous drives of at least 90-minutes duration, but the nature and frequency of such interventions appear to be a key factor in their effectiveness. Results also suggest that performance might be best sustained by taking very frequent breaks, and although this might be impractical in the context of driving, this finding might be applied to a broad range of tasks that require sustained attention, including operations in security and quality control

Reconstruction of total marine fisheries catches for Germany in the North Sea (1950-2010)

We reconstructed marine fisheries catches for the Federal Republic of Germany within the North Sea (specifically ICES area IVb) from 1950-2010. ICES landings statistics are used as a reported baseline, and then adjusted using information from ICES stock assessment working group reports, national data, and expert knowledge to estimate unreported landings, recreational and subsistence catches and major discards. Brown shrimp (Crangon crangon) contribute the most to unreported landings and discards. Atlantic herring (Clupea harengus), Atlantic cod (Gadus morhua) and European plaice (Pleuronectes platessa) are also important fisheries for the period 1950-2010. The reconstructed total catch of 8.5 million t from 1950-2010 was approximately 63% higher than the baseline reported ICES landings of 5.2 million t. The reconstructed total catch of invertebrates is almost 4 million t, which is 2 times the ICES baseline catch which is just over 1.9 million t. The reconstructed catch for all finfish species is 4.6 million t and is 41% higher than the ICES baseline catch of 3.3 million t. These discrepancies are largely driven by discarded catches that are not accounted for in officially reported (ICES) data, which also form the globally reported data as presented by the Food and Agriculture Organization of the United Nations. Our results demonstrate the importance of comprehensively accounting for and disclosing fisheries data to the public (including discarded catches), and effectively monitoring Illegal, Unreported and Unregulated (IUU) catches

Fishery biomass trends of exploited fish populations in marine ecoregions, climatic zones and ocean basins

Highlights: • 1st global long-term fishery biomass trends evaluation of 1300 exploited marine populations. • Decline in average fishery biomass observed across oceans and climate zones. • Systemic wide-spread overfishing of the world's coastal and continental shelf water. Abstract: This contribution presents time series of the ‘fishery biomass’ of fish populations, defined as the weight (whole-body, wet weight) of the in-water part of a fishable population, i.e., that part of a population (also called ‘stock’) that is exposed to a certain fishing gear. Detailed data of this type are only available for a limited number of species that are targets of the fisheries in the waters of economically developed regions, such as Europe, the USA, Canada or Australia. However, similar fishery biomass assessments are generally lacking for developing countries, even for many of their most heavily fished species. Here, an estimation of the long-term fishery biomass trends of 1320 fish and invertebrate populations for 483 species exploited by fisheries in the 232 coastal Marine Ecoregions (MEs) around the world was undertaken. Fishery biomass trends were derived using the Bayesian CMSY stock assessment method applied to the global fisheries catch database for 1950–2014 as reconstructed by the Sea Around Us for every maritime fishing country in the world. Overall, the results suggest a consistent decline in the fishery biomass of exploited populations, in virtually all climatic zones and ocean basins in the world. The only zone with currently higher fishery biomass than in 1950 is the northern Pacific polar-boreal zone, likely due to environmental changes that occurred in the region positively affecting fish populations, combined with prudent management of the fisheries. For populations in MEs that are known to have highly questionable catch statistics, the results suggested smaller declines in fishery biomass than likely occurred in reality, implying that these results do not exaggerate declining trends in fishery biomass. This study used informative Bayesian priors to improve the trend analyses in areas where systematic stock assessments were conducted. The use of these independent assessments reduced the uncertainty associated with the findings of this study

Overcoming water diffusion limitations in hydrogels via microtubular graphene networks for soft actuators

Hydrogel-based soft actuators can operate in sensitive environments, bridging the gap of rigid machines interacting with soft matter. However, while stimuli-responsive hydrogels can undergo extreme reversible volume changes of up to ~90%, water transport in hydrogel actuators is in general limited by their poroelastic behavior. For poly(N-isopropylacrylamide) (PNIPAM) the actuation performance is even further compromised by the formation of a dense skin layer. Here we show, that incorporating a bioinspired microtube graphene network into a PNIPAM matrix with a total porosity of only 5.4 % dramatically enhances actuation dynamics by up to ~400 % and actuation stress by ~4000 % without sacrificing the mechanical stability, overcoming the water transport limitations. The graphene network provides both untethered light-controlled and electrically-powered actuation. We anticipate that the concept provides a versatile platform for enhancing the functionality of soft matter by combining responsive and two-dimensional materials, paving the way towards designing soft intelligent matter.Comment: Shared First-authorship: Margarethe Hauck and Lena Marie Saur

Microengineered Hollow Graphene Tube Systems Generate Conductive Hydrogels with Extremely Low Filler Concentration

The fabrication of electrically conductive hydrogels is challenging as the introduction of an electrically conductive filler often changes mechanical hydrogel matrix properties. Here, we present an approach for the preparation of hydrogel composites with outstanding electrical conductivity at extremely low filler loadings (0.34 S m-1, 0.16 vol %). Exfoliated graphene and polyacrylamide are microengineered to 3D composites such that conductive graphene pathways pervade the hydrogel matrix similar to an artificial nervous system. This makes it possible to combine both the exceptional conductivity of exfoliated graphene and the adaptable mechanical properties of polyacrylamide. The demonstrated approach is highly versatile regarding porosity, filler material, as well as hydrogel system. The important difference to other approaches is that we keep the original properties of the matrix, while ensuring conductivity through graphene-coated microchannels. This novel approach of generating conductive hydrogels is very promising, with particular applications in the fields of bioelectronics and biohybrid robotics

What catch data can tell us about the status of global fisheries

The only available data set on the catches of global fisheries are the official landings reported annually by the Food and Agriculture Organization of the United Nations (FAO). Attempts to detect and interpret trends in these data have been criticized as being both technically and conceptually flawed. Here, we explore and refute these claims. We show explicitly that trends in catch data are not an artifact of the applied method and are consistent with trends in biomass data of fully assessed stocks. We also show that, while comprehensive stock assessments are the preferred method for evaluating single stocks, they are a biased subsample of the stocks in a given area, strongly underestimating the percentage of collapsed stocks. We concur with a recent assessment-based analysis by FAO that the increasing trends in the percentage of overexploited, depleted, and recovering stocks and the decreasing trends in underexploited and moderately exploited stocks give cause for concern. We show that these trends are much more pronounced if all available data are considered