Massa de Brachiaria ruziziensis em consórcio com diferentes populações e genótipos de milho safrinha (Zea mays L.), em Maracajú, 2007.

bitstream/item/65387/1/29900.pdfOrganizado por Gessi Ceccon e Luiz Alberto Staut

Records of five bryozoan species from offshore gas platforms rare for the Dutch North Sea

This study reports on bryozoan species collected at three offshore gas platforms in the Dutch part of the North Sea. Four out of thirteen observed species are considered as rare in the Netherlands, whereas Cribrilina punctata is anew species for Dutch waters

A Review Characterizing 25 Ecosystem Challenges to Be Addressed by an Ecosystem Approach to Fisheries Management in Europe

The impacts of fisheries on ocean resources are no longer considered in isolation but should account for broader ecosystem effects. However, ongoing ecosystem-wide changes added to the inherent dynamics of marine ecosystems, create challenges for fisheries and fisheries management by affecting our ability to ensure future fishing opportunities and sustainable use of the seas. By reviewing a corpus of fisheries science literature, we contribute to informing managers and policymakers with considerations of the various threats to fisheries and the marine ecosystems that support them. We identify and describe 25 ecosystem challenges and 7 prominent families of management options to address them. We capture the challenges acting within three broad categories: (i) fishing impacts on the marine environments and future fishing opportunities, (ii) effects of environmental conditions on fish and fishing opportunities, and (iii) effects of context in terms of socioeconomics, fisheries management, and institutional set-up on fisheries. Our review shows that, while most EU fisheries are facing a similar array of challenges, some of them are specific to regions or individual fisheries. This is reflected in selected regional cases taking different perspectives to exemplify the challenges along with fishery-specific cases. These cases include the dramatic situation of the Baltic Sea cod, facing an array of cumulative pressures, the multiple and moving ecosystem interactions that rely on the North Sea forage fish facing climate change, the interaction of fishing and fish stocks in a fluctuating mixed fishery in the Celtic Sea, the bycatch of marine mammals and seabirds and habitat degradation in the Bay of Biscay, and finally the under capacity and lack of fundamental knowledge on some features of the EU Outermost Regions. In addition to these ecoregion specific findings, we discuss the outcomes of our review across the whole of European waters and we conclude by recognizing that there are knowledge gaps regarding the direction of causality, nonlinear responses, and confounding effects. All of the challenges we identify and characterize may guide further data collection and research coordination to improve our fundamental understanding of the system and to monitor real changes within it, both of which are required to inform an Ecosystem Approach to Fisheries Management (EAFM). An European EAFM could build upon an array of management measures currently tailored for fisheries management only, including promoting funding interdisciplinary research and ecosystem monitoring. Such integrative management should reduce uncertainties in environmental, social and economic trends, and lower the risk for disruptive events or ecosystem effects with far-reaching consequences, including a shift toward less productive marine ecosystems.En prens

Selenium status is positively associated with bone mineral density in healthy aging European men

Objective It is still a matter of debate if subtle changes in selenium (Se) status affect thyroid function tests (TFTs) and bone mineral density (BMD). This is particularly relevant for the elderly, whose nutritional status is more vulnerable. Design and Methods We investigated Se status in a cohort of 387 healthy elderly men (median age 77 yrs; inter quartile range 75-80 yrs) in relation to TFTs and BMD. Se status was determined by measuring both plasma selenoprotein P (SePP) and Se. Results The overall Se status in our population was low normal with only 0.5% (2/387) of subjects meeting the criteria for Se deficiency. SePP and Se levels were not associated with thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), triiodothyronine (T3) or reverse triiodothyronine (rT3) levels. The T3/T4 and T3/rT3 ratios, reflecting peripheral metabolism of thyroid hormone, were not associated with Se status either. SePP and Se were positively associated with total BMD and femoral trochanter BMD. Se, but not SePP, was positively associated with femoral neck and ward's BMD. Multivariate linear analyses showed that these associations remain statistically significant in a model including TSH, FT4, body mass index, physical performance score, age, smoking, diabetes mellitus and number of medication use. Conclusion Our study demonstrates that Se status, within the normal European marginally supplied range, is positively associated with BMD in healthy aging men, independent of thyroid function. Thyroid function tests appear unaffected by Se status in this population

Marine fish traits follow fast-slow continuum across oceans

A fundamental challenge in ecology is to understand why species are found where they are and predict where they are likely to occur in the future. Trait-based approaches may provide such understanding, because it is the traits and adaptations of species that determine which environments they can inhabit. It is therefore important to identify key traits that determine species distributions and investigate how these traits relate to the environment. Based on scientific bottom-trawl surveys of marine fish abundances and traits of >1,200 species, we investigate trait-environment relationships and project the trait composition of marine fish communities across the continental shelf seas of the Northern hemisphere. We show that traits related to growth, maturation and lifespan respond most strongly to the environment. This is reflected by a pronounced “fast-slow continuum” of fish life-histories, revealing that traits vary with temperature at large spatial scales, but also with depth and seasonality at more local scales. Our findings provide insight into the structure of marine fish communities and suggest that global warming will favour an expansion of fast-living species. Knowledge of the global and local drivers of trait distributions can thus be used to predict future responses of fish communities to environmental change.Postprint2,92

Hyponatremia revisited: Translating physiology to practice

The complexity of hyponatremia as a clinical problem is likely caused by the opposite scenarios that accompany this electrolyte disorder regarding pathophysiology (depletional versus dilutional hyponatremia, high versus low vasopressin levels) and therapy (rapid correction to treat cerebral edema versus slow correction to prevent osmotic demyelination, fluid restriction versus fluid resuscitation). For a balanced differentiation between these opposites, an understanding of the pathophysiology of hyponatremia is required. Therefore, in this review an attempt is made to translate the physiology of water balance regulation to strategies that improve the clinical management of hyponatremia. A physiology-based approach to the patient with hyponatremia is presented, first addressing the possibility of acute hyponatremia, and then asking if and if so why vasopressin is secreted non-osmotically. Additional diagnostic recommendations are not to rely too heavily of the assessment of the extracellular fluid volume, to regard the syndrome of inappropriate antidiuresis as a diagnosis of exclusion, and to rationally investigate the pathophysiology of hyponatremia rather than to rely on isolated laboratory values with arbitrary cutoff values. The features of the major hyponatremic disorders are discussed, including diuretic-induced hyponatremia, adrenal and pituitary insufficiency, the syndrome of inappropriate antidiuresis, cerebral salt wasting, and exercise-associated hyponatremia. The treatment of hyponatremia is reviewed from simple saline solutions to the recently introduced vasopressin receptor antagonists, including their promises and limitations. Given the persistently high rates of hospital-acquired hyponatremia, the importance of improving the management of hyponatremia seems both necessary and achievable. Copyrigh

Are we ready to track climate-driven shifts in marine species across international boundaries? - A global survey of scientific bottom trawl data

Marine biota are redistributing at a rapid pace in response to climate change and shifting seascapes. While changes in fish populations and community structure threaten the sustainability of fisheries, our capacity to adapt by tracking and projecting marine species remains a challenge due to data discontinuities in biological observations, lack of data availability, and mismatch between data and real species distributions. To assess the extent of this challenge, we review the global status and accessibility of ongoing scientific bottom trawl surveys. In total, we gathered metadata for 283,925 samples from 95 surveys conducted regularly from 2001 to 2019. We identified that 59% of the metadata collected are not publicly available, highlighting that the availability of data is the most important challenge to assess species redistributions under global climate change. Given that the primary purpose of surveys is to provide independent data to inform stock assessment of commercially important populations, we further highlight that single surveys do not cover the full range of the main commercial demersal fish species. An average of 18 surveys is needed to cover at least 50% of species ranges, demonstrating the importance of combining multiple surveys to evaluate species range shifts. We assess the potential for combining surveys to track transboundary species redistributions and show that differences in sampling schemes and inconsistency in sampling can be overcome with spatio-temporal modeling to follow species density redistributions. In light of our global assessment, we establish a framework for improving the management and conservation of transboundary and migrating marine demersal species. We provide directions to improve data availability and encourage countries to share survey data, to assess species vulnerabilities, and to support management adaptation in a time of climate-driven ocean changes.En prensa6,86

Improvement of greater argentine stock assessment

An ongoing commercial market sampling for the Dutch greater argentine fishery is carried out by WMR in collaboration with the pelagic fishing fleet of the Netherlands. Start of this sampling programme goes back to year 1990. The aim of this programme is to achieve a haul-level sampling each year, stratified in area and time within the targeted ICES division. Later, market sampling data is pooled with respect to the quarter and the ICES divisions and the inferred age structure to is allocated to the catch, a classical ALK is generated from the collected age-length data which describes the probability of age given length (Fridriksson 1934). The sample sizes in this long time series can be relatively low in some years and the coverage can be relatively limited in space and time. The additional data sets, collected outside of this program, such as length composition data collected by self-sampling of PFA, maybe useful for filling some of these gaps and improve the level of accuracy of the estimations. However, this approach requires - A detailed understanding of the characteristics of the data set and the patterns in the market sampling time series. - A careful comparison between the datasets while assessing the quality and consistency of the measurements - Adoption of an unbiased method to incorporate age structure information from one dataset to the other. In the first section of the report, the characteristics of the two datasets are explained such as the sampling strategy, sample processing, sample size as well as the demographic changes over the years. Secondly the results of the comparison between the two datasets are presented. The initial aim was to focus on the samples from the two different sampling programs overlapping in space and time. However the level of overlap was not as close as expected. Nevertheless the closest samples in space and time selected and compared. It was found that the resemblance between the datasets did not show a pattern that can be explained with the distance or time between the samples. This is most likely due to stochasticity of the length distributions. A secondary problem that was tackled with was the lack of age information in the PFA data sets. Although length distributions can be an indirect indicator of the age structure a cohort estimation can not be acquired from the length distribution due to slow growth and long life span of the species. One solution would be inferring such missing ages using the available age/length information. Currently, classical age/length keys are commonly used to extrapolate otolith readings to length composition. Unfortunately the classical ALK obtained with data from one year/area cannot be applied to another year/area, because the underlying structure of the population may change due to variation in recruitment, survival or growth. An alternative is the use of an inverse key, which describes the probability of length given age, and has the benefit that this probability is not affected by variation in recruitment and survival. An inverse key can be applied to other years or areas, but under the assumption that size at age does not vary between years or areas. Another alternative is the combined forward-inverse key (hereafter called ‘combined key’) which combines the forward and inverse key into one approach (Hoenig et al. 2002). It uses Bayes’ rule to implement the forward and inverse key into one maximum likelihood framework through the probability of length at age. In this work, we applied the combined key using an R package implementation ( ‘ALKr’) by Murta et al. (2016). For this exercise, we used market age/length samples to build a combined key for greater greater argentine and compared it with the results obtained by the classical ALK. We further used the constructed combined key to estimate the age composition for the catch of samples by the PFA based on their length measurements. The resulting combined key is a promising solution for estimating the age composition in the PFA self-sampling data set, from which the length composition could be used as an input. However before that it is necessary to ensure that the this length composition time series is free from systematic biases with reasonable accuracy. Therefore a comprehensive check was carried out for the PFA length frequency data while using the market sampling dataset as a reference. The results are presented in this report. Lastly stock assessment tests were performed for the greater argentine by with and without incorporation of the PFA data, and the results are discussed