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

A genome-wide association study for blood lipid phenotypes in the Framingham Heart Study

<p>Abstract</p> <p>Background</p> <p>Blood lipid levels including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) are highly heritable. Genome-wide association is a promising approach to map genetic loci related to these heritable phenotypes.</p> <p>Methods</p> <p>In 1087 Framingham Heart Study Offspring cohort participants (mean age 47 years, 52% women), we conducted genome-wide analyses (Affymetrix 100K GeneChip) for fasting blood lipid traits. Total cholesterol, HDL-C, and TG were measured by standard enzymatic methods and LDL-C was calculated using the Friedewald formula. The long-term averages of up to seven measurements of LDL-C, HDL-C, and TG over a ~30 year span were the primary phenotypes. We used generalized estimating equations (GEE), family-based association tests (FBAT) and variance components linkage to investigate the relationships between SNPs (on autosomes, with minor allele frequency ≥10%, genotypic call rate ≥80%, and Hardy-Weinberg equilibrium p ≥ 0.001) and multivariable-adjusted residuals. We pursued a three-stage replication strategy of the GEE association results with 287 SNPs (P < 0.001 in Stage I) tested in Stage II (n ~1450 individuals) and 40 SNPs (P < 0.001 in joint analysis of Stages I and II) tested in Stage III (n~6650 individuals).</p> <p>Results</p> <p>Long-term averages of LDL-C, HDL-C, and TG were highly heritable (h²= 0.66, 0.69, 0.58, respectively; each P < 0.0001). Of 70,987 tests for each of the phenotypes, two SNPs had p < 10^-5in GEE results for LDL-C, four for HDL-C, and one for TG. For each multivariable-adjusted phenotype, the number of SNPs with association p < 10^-4ranged from 13 to 18 and with p < 10^-3, from 94 to 149. Some results confirmed previously reported associations with candidate genes including variation in the lipoprotein lipase gene (<it>LPL</it>) and HDL-C and TG (rs7007797; P = 0.0005 for HDL-C and 0.002 for TG). The full set of GEE, FBAT and linkage results are posted at the <b>d</b>ata<b>b</b>ase of <b>G</b>enotype <b>a</b>nd <b>P</b>henotype (dbGaP). After three stages of replication, there was no convincing statistical evidence for association (i.e., combined P < 10^-5across all three stages) between any of the tested SNPs and lipid phenotypes.</p> <p>Conclusion</p> <p>Using a 100K genome-wide scan, we have generated a set of putative associations for common sequence variants and lipid phenotypes. Validation of selected hypotheses in additional samples did not identify any new loci underlying variability in blood lipids. Lack of replication may be due to inadequate statistical power to detect modest quantitative trait locus effects (i.e., <1% of trait variance explained) or reduced genomic coverage of the 100K array. GWAS in FHS using a denser genome-wide genotyping platform and a better-powered replication strategy may identify novel loci underlying blood lipids.</p

Tannin- caprolactam and Tannin- PEG formulations as outdoor wood preservatives: Weathering properties

International audienceAbstractKey messageThis article presents the leaching, fire and weathering resistance improvements of samples treated with tannin-based wood preservatives added of caprolactam. PEG-added formulations show limited applicability. The FT-IR and13C-NMR analyses of the caprolactam-added formulations show some evidences of copolymerization.ContextTannin-boron wood preservatives are known for their high resistance against leaching, biological attacks, fire as well as for the good mechanical properties that they impart to wood. These properties promoted these formulations for being a candidate for the protection of green buildings. However, the low elasticity of these polymers and their dark colour implied limited weathering resistances.AimsThe aim of the study is to find suitable additives for tannin-based formulations to overcome their limited weathering resistances, without compromising the other properties.MethodsTreatment, leaching and fire tests, dimensional stability as well as artificial and natural weathering of the timber treated with caprolactam-added and PEG-added formulations were performed. FT-IR and 13C-NMR of the formulations were presented.ResultsThe presence of caprolactam improved the properties of the formulation with particularly significant results in terms of resistance against leaching and dimensional stability. These enhancements were imparted also to the weathering resistance of the tannin-caprolactam formulations. Indeed, the colour changes during the artificial and natural exposures were stable for longer periods. FT-IR and 13C-NMR investigations of the advanced formulations were led, and covalent copolymerization of the caprolactam with the tannin-hexamine polymer was observed.ConclusionThe tannin formulations with caprolactam improved the durability of the wood specimens, while the PEG-tannin presented strong application drawbacks

Effects of ocean sprawl on ecological connectivity: impacts and solutions

The growing number of artificial structures in estuarine, coastal and marine environments is causing “ocean sprawl”. Artificial structures do not only modify marine and coastal ecosystems at the sites of their placement, but may also produce larger-scale impacts through their alteration of ecological connectivity - the movement of organisms, materials and energy between habitat units within seascapes. Despite the growing awareness of the capacity of ocean sprawl to influence ecological connectivity, we lack a comprehensive understanding of how artificial structures modify ecological connectivity in near- and off-shore environments, and when and where their effects on connectivity are greatest. We review the mechanisms by which ocean sprawl may modify ecological connectivity, including trophic connectivity associated with the flow of nutrients and resources. We also review demonstrated, inferred and likely ecological impacts of such changes to connectivity, at scales from genes to ecosystems, and potential strategies of management for mitigating these effects. Ocean sprawl may alter connectivity by: (1) creating barriers to the movement of some organisms and resources - by adding physical barriers or by modifying and fragmenting habitats; (2) introducing new structural material that acts as a conduit for the movement of other organisms or resources across the landscape; and (3) altering trophic connectivity. Changes to connectivity may, in turn, influence the genetic structure and size of populations, the distribution of species, and community structure and ecological functioning. Two main approaches to the assessment of ecological connectivity have been taken: (1) measurement of structural connectivity - the configuration of the landscape and habitat patches and their dynamics; and (2) measurement of functional connectivity - the response of organisms or particles to the landscape. Our review reveals the paucity of studies directly addressing the effects of artificial structures on ecological connectivity in the marine environment, particularly at large spatial and temporal scales. With the ongoing development of estuarine and marine environments, there is a pressing need for additional studies that quantify the effects of ocean sprawl on ecological connectivity. Understanding the mechanisms by which structures modify connectivity is essential if marine spatial planning and eco-engineering are to be effectively utilised to minimise impacts

A stellar overdensity associated with the Small Magellanic Cloud

We report the discovery of a stellar over-density 8$^{\circ}$ north of the center of the Small Magellanic Cloud (Small Magellanic Cloud Northern Over-Density; SMCNOD) using data from the first two years of the Dark Energy Survey (DES) and the first year of the MAGellanic SatelLITEs Survey (MagLiteS). The SMCNOD is indistinguishable in age, metallicity and distance from the nearby SMC stars, being primarly composed of intermediate-age stars (6 Gyr, Z=0.001), with a small fraction of young stars (1 Gyr, Z=0.01). The SMCNOD has an elongated shape with an ellipticity of 0.6 and a size of $\sim$ 6x2 deg. It has an absolute magnitude of $M_V \cong$ -7.7, $r_h = 2.1$ kpc, and $\mu_V(r<r_h)$ = 31.2 mag arcsec$^{-2}$. We estimate a stellar mass of $\sim 10^5$ $M_{\odot}$, following a Kroupa mass function. The SMCNOD was probably removed from the SMC disk by tidal stripping, since it is located near the head of the Magellanic Stream, and the literature indicates likely recent LMC-SMC encounters. This scenario is supported by the lack of significant HI gas. Other potential scenarios for the SMCNOD origin are a transient over-density within the SMC tidal radius or a primordial SMC satellite in advanced stage of disruption.Comment: 14 pages, 10 color figure

The scale of competition impacts parasite virulence evolution

International audienceThe structure of parasite populations can have important consequences for virulence evolution. Both the scale of competition, whether it is more intense in the within versus between host environment, and the mode of transmission, whether parasites transmit alone or in groups between hosts, influence population structure and can select for changes in virulence.In a selection experiment, we evolved metapopulations of the spider mite parasite Tetranychus urticae, under local (fixed sampling per host patch) or global (sampling determined by host patch productivity) competition, with either co- (with a female parasite from the same host patch) or random (with parasites from different host patches) transmission. After 33 generations of evolution, the fecundity and virulence of each replicate population was measured.Females from the ‘local-random’ regime were more virulent with higher fecundity than females from the ‘global-random’ regime. There was no difference in virulence or fecundity between females from the ‘global-random’ or ‘global co-transmission’ selection regimes.These results show that the scale of competition, and not the type of transmission, impacted virulence evolution for T. urticae. Local competition may maintain higher levels of genetic diversity at the level of the metapopulation. As such, intense local, within-host, competition selected for more productive individuals better able to exploit their environment and be the one to transmit to a new host

Permafrost controls the displacement rates of large unstable rock-slopes in subarctic environments

International audienceDetermining the link between permafrost and the displacement rates of large unstable rock-slopes (LURSs) is fundamental for understanding future hazard scenarios and establishing appropriate management strategies. From an inventory of >500 LURSs in Norway, we investigate the controls of those with available information on their displacement rates (299 LURSs), presenting the first statistical evidence of permafrost as the main driver of displacement rates of LURSs. The probability for a LURS to displace if permafrost is present now or was during the Little Ice Age (LIA) is around 2.1 times higher than if permafrost was already absent during the LIA. This probability is 1.5 times higher for LURSs with current permafrost than for LURSs with permafrost during the LIA that has since melted. Therefore, our findings enrich the classical conception that warming of permafrost increases displacement rates of LURSs, by showing that the complete thawing of permafrost can result in a decrease in displacement rate or even a complete halt of displacement