Hook shedding and post-release fate of deep-hooked European eel

-The European eel (Anguilla anguilla) is a commercially and recreationally important fishery target species. In the last decades, the eel has experienced dramatic stock declines and has been listed as critically endangered. To reduce fishing mortality, several European countries have closed the fishery or introduced stricter management measures which increase the likelihood of catch-and-release in the recreational fishery. This study investigated hook shedding mechanisms of deep-hooked, line-cut eels via radiography, and quantified hook shedding rates, post-release mortality and sub-lethal effects in captivity. Eels were caught with four different hook treatments, monitored in a tank for 23 weeks, and radiographed 0, 1, 3, 10, 24, 54, 115 and 163 days after capture. After 163 days, total hook shedding rate was significantly higher for smaller hooks (41.2%) compared to larger hooks (0.0%), and increased with fish length. Post-release mortality rates ranged between 27.3% and 50.0% after 23 weeks (not adjusted for handling and holding) and did not differ significantly between hook treatments. The majority of dead eels showed gastric perforations caused by the hooks leading to internal haemorrhaging and the intrusion of digestive fluids into the body cavity inducing lethal degradation and inflammation of vital organs. Anglers are encouraged to minimise bycatch of eel in countries where eel harvest is prohibited. Anglers targeting eel should use selective and appropriate fishing gears, baits and tactics (e.g. very large hooks, immediate hook setting after a bite) to reduce deep hooking and the catch of undersized eels, ultimately promoting the eel's conservation

Estimating and mitigating post-release mortality of European eel by combining citizen science with a catch-and-release angling experiment

Several anguillid eel species have experienced severe population declines over the past decades, particularly the European eel (Anguilla anguilla), which is listed as critically endangered by the International Union for Conservation of Nature. To reduce fishing mortality, many European countries have introduced strict recreational eel fishing regulations increasing regulatory catch-and-release (C&R) practice. Despite high release rates, only limited information exists on the potential consequences of C&R on eels. A field experiment was conducted with pre-tagged eels in a semi-natural environment to investigate lethal and sublethal impacts of C&R. The experiment was combined with a citizen science study evaluating the effects of different hooks on catch rates, fish size, and hooking location to develop best practice guidelines. Short-term mortality (≤72 h) ranged from 0.0–18.2%, and adjusted long-term mortality (>72 h) from 0.0–46.2% depending on treatments, resulting in adjusted total mortality rates between 8.4% and 64.4% at the end of the study period (≥43 d). The only significant predictor of mortality was the occurrence of bleeding from hooking injuries. Deep hooking was common, and only few deep-hooked eels for which the fishing line was cut and the hook left in place shed the hook after release. However, no significant effect of C&R on eel condition was found. The citizen science study showed that anglers can significantly decrease the catch of small eels, and thus release rates, by using large J-hooks. Furthermore, large J-hooks or circle hooks reduced the likelihood of deep hooking compared to small J-hooks. Post-release mortality of eels caught in recreational fisheries needs to be considered in future stock assessments and management plans to ensure conservation of the European eel. This study also highlights the strength of combining citizen science with experimental studies to develop best practice guidelines promoting fish conservation.publishedVersio

The impact of marine recreational fishing on key fish stocks in European waters

Marine recreational fishing (MRF) has been shown to substantially contribute to fishing mortality of marine fish. However, European MRF catches are only quantified for a small number of stocks, so it is unclear whether a significant part of fishing mortality is excluded from stock assessments. This study estimated: (i) European MRF removals, which were defined as landings plus dead releases; and (ii) impact at stock level by comparing the percentage contribution to total removal by MRF and commercial fishing. As MRF data were limited for some European countries, catches were reconstructed using a mixture of average release proportions, average fish weights, and extrapolation using the catch per fisher of the nearest country providing catch estimates. Where catch reconstructions exceeded 50%, data were excluded from further analysis. Furthermore, as MRF survey methodology can be variable, semi-quantitative estimates of bias and error were calculated for each stock. Only 10 of the 20 stocks assessed in this study had sufficient MRF data for full reliable estimates. Percentage contribution to total removals (MRF + commercial removals) by MRF ranged between 2% for Atlantic mackerel in the North Sea and Skagerrak and 43% for Atlantic pollack in the Celtic Seas and English Channel. The biomass removed ranged between 297 (± 116) tonnes (Atlantic cod in the western English Channel and southern Celtic seas) and 4820 (± 1889) tonnes (Atlantic mackerel in the North Sea and Skagerrak), but the errors were substantial. Additionally, the bias in the estimated removals was low for most stocks, with some positive biases found. The present study indicates that removals by MRF can represent a high proportion of the total removals for some European marine fish stocks, so inclusion in stock assessments should be routine. To achieve this, regular surveys of MRF are required to collect data essential for stock assessments

CERT1 mutations perturb human development by disrupting sphingolipid homeostasis

Neural differentiation, synaptic transmission, and action potential propagation depend on membrane sphingolipids, whose metabolism is tightly regulated. Mutations in the ceramide transporter CERT (CERT1), which is involved in sphingolipid biosynthesis, are associated with intellectual disability, but the pathogenic mechanism remains obscure. Here, we characterize 31 individuals with de novo missense variants in CERT1. Several variants fall into a previously uncharacterized dimeric helical domain that enables CERT homeostatic inactivation, without which sphingolipid production goes unchecked. The clinical severity reflects the degree to which CERT autoregulation is disrupted, and inhibiting CERT pharmacologically corrects morphological and motor abnormalities in a Drosophila model of the disease, which we call ceramide transporter (CerTra) syndrome. These findings uncover a central role for CERT autoregulation in the control of sphingolipid biosynthetic flux, provide unexpected insight into the structural organization of CERT, and suggest a possible therapeutic approach for patients with CerTra syndrome

CERT1 mutations perturb human development by disrupting sphingolipid homeostasis

Neural differentiation, synaptic transmission, and action potential propagation depend on membrane sphingolipids, whose metabolism is tightly regulated. Mutations in the ceramide transporter CERT (CERT1), which is involved in sphingolipid biosynthesis, are associated with intellectual disability, but the pathogenic mechanism remains obscure. Here, we characterize 31 individuals with de novo missense variants in CERT1. Several variants fall into a previously uncharacterized dimeric helical domain that enables CERT homeostatic inactivation, without which sphingolipid production goes unchecked. The clinical severity reflects the degree to which CERT autoregulation is disrupted, and inhibiting CERT pharmacologically corrects morphological and motor abnormalities in a Drosophila model of the disease, which we call ceramide transporter (CerTra) syndrome. These findings uncover a central role for CERT autoregulation in the control of sphingolipid biosynthetic flux, provide unexpected insight into the structural organization of CERT, and suggest a possible therapeutic approach for patients with CerTra syndrome.This work was supported by the National Institute of Neurological Disorders and Stroke (NINDS), NIH (R01NS109858, to VAG); the Paul A. Marks Scholar Program at the Columbia University Vagelos College of Physicians and Surgeons (to VAG); a TIGER grant from the TAUB Institute at the Columbia Vagelos College of Physicians and Scientists (to VAG); the Swiss National Science Foundation (SNF 31003A-179371, to TH); the European Joint Program on Rare Diseases (EJP RD+SNF 32ER30-187505, to TH); the Swiss Cancer League (KFS-4999-02-2020, to GD); the EPFL institutional fund (to GD); the Kristian Gerhard Jebsen Foundation (to GD); the Swiss National Science Foundation (SNSF) (310030_184926, to GD); the Swiss Foundation for Research on Muscle Disease (FSRMM, to MAL); the Natural Science and Engineering Research Council of Canada (Discovery Grant 2020-04241, to JEB); the Italian Ministry of Health Young Investigator Grant (GR-2011-02347754, to EL); the Fondazione Istituto di Ricerca Pediatrica – Città della Speranza (18-04, to EL); the Wroclaw Medical University (SUB.E160.21.004, to RS); the National Science Centre, Poland (2017/27/B/NZ5/0222, to RS); Telethon Undiagnosed Diseases Program (TUDP) (GSP15001); the Temple Street Foundation/Children’s Health Foundation Ireland (RPAC 19-02, to IK); the Deutsche Forschungsgemeinschaft (DFG) (PO2366/2–1, to BP); the Instituto de Salud Carlos III, Spain (to ELM, EBS, and BMD); the National Natural Science Foundation of China (81871079 and 81730036, to HG and KX); and the National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH (R01 DK115574, to SSC).The DEFIDIAG study is funded by grants from the French Ministry of Health in the framewok of the national French initiative for genomic medicine. The funders were not involved in the study design, data acquisition, analysis, or writing of the manuscript. Funding for the DECIPHER project was provided by Wellcome. The DDD study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between Wellcome and the Department of Health, and the Wellcome Sanger Institute (grant number WT098051). The views expressed in this publication are those of the author(s) and not necessarily those of Wellcome or the Department of Health. The study has UK Research Ethics Committee approval (10/H0305/83, granted by the Cambridge South REC, and GEN/284/12, granted by the Republic of Ireland REC). The research team acknowledges the support of the National Institute for Health Research, through the Comprehensive Clinical Research Network.S

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

<i>GRIN2A</i>-related disorders:genotype and functional consequence predict phenotype

Alterations of the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2A, encoded by GRIN2A, have been associated with a spectrum of neurodevelopmental disorders with prominent speech-related features, and epilepsy. We performed a comprehensive assessment of phenotypes with a standardized questionnaire in 92 previously unreported individuals with GRIN2A-related disorders. Applying the criteria of the American College of Medical Genetics and Genomics to all published variants yielded 156 additional cases with pathogenic or likely pathogenic variants in GRIN2A, resulting in a total of 248 individuals. The phenotypic spectrum ranged from normal or near-normal development with mild epilepsy and speech delay/apraxia to severe developmental and epileptic encephalopathy, often within the epilepsy-aphasia spectrum. We found that pathogenic missense variants in transmembrane and linker domains (misTMD+Linker) were associated with severe developmental phenotypes, whereas missense variants within amino terminal or ligand-binding domains (misATD+LBD) and null variants led to less severe developmental phenotypes, which we confirmed in a discovery (P = 10-6) as well as validation cohort (P = 0.0003). Other phenotypes such as MRI abnormalities and epilepsy types were also significantly different between the two groups. Notably, this was paralleled by electrophysiology data, where misTMD+Linker predominantly led to NMDAR gain-of-function, while misATD+LBD exclusively caused NMDAR loss-of-function. With respect to null variants, we show that Grin2a+/- cortical rat neurons also had reduced NMDAR function and there was no evidence of previously postulated compensatory overexpression of GluN2B. We demonstrate that null variants and misATD+LBD of GRIN2A do not only share the same clinical spectrum (i.e. milder phenotypes), but also result in similar electrophysiological consequences (loss-of-function) opposing those of misTMD+Linker (severe phenotypes; predominantly gain-of-function). This new pathomechanistic model may ultimately help in predicting phenotype severity as well as eligibility for potential precision medicine approaches in GRIN2A-related disorders

Integrated natural resources management of coastal fisheries

Das Untersuchungsgebiet, die Nha Phu Lagune, weist eine massive Degradation der fischereilichen Ressourcen auf. Die „Rural Livelihoods“ in den Gemeinden dieser Küstenregionen sind durch diese Degradation gefährdet. Da, die Ressourcennutzungsentscheidungen einzelner Haushalte von vielen Faktoren abhängen, bedarf es eines multi-sektoralen Forschungsansatzes. Dieser ermöglicht, die Komplexität und die Diversität des Ressourcennutzungssystems und seine Nutzer, zu erfassen. Das Integrated Natural Resources Management (INRM) ist ein multi-sektoraler Forschungsansatz, der innovative und flexible Managementformen zu entwickeln versucht, um natürliche Ressourcen nachhaltig zu nutzen. Interdisziplinarität und die Betonung von Partizipation sind zentrale Kennzeichen des angewandten INRM-Forschungsansatzes. Diese interdisziplinäre Vorgehensweise berücksichtigt sowohl sozio-ökonomische und institutionelle Einflussfaktoren, z.B. Ressourcennutzer-Gruppen und bestehende Regulierungen und Gesetze, als auch biologische und produktionstechnische Einflussfaktoren, z.B. Aquakultur und Fischfangtechniken. Während eines sechs monatigen Untersuchungszeitraums unter Anwendung Partizipativer Aktionsforschung und des INRM-Ansatzes wurden 12 Dörfer im Umkreis der Nha Phu Lagune besucht. Der innerhalb der Partizipativen Aktionsforschung angesiedelte Lernzyklus generiert Wissen durch die Reflektion von gesammelten Daten, die kontinuierlich an die Beteiligten zurückgeführt werden. Die Erhebung mittels Fragebögen, halbstrukturierter Interviews, Gruppendiskussionen, Observierung, „Resource Mapping“ und Venn Diagrammen identifizierte Ursachen für die Degradation fischereilicher Ressourcen. Diese Informationen wurden dann an die Beteiligten weitergereicht, was zu neuen Erkenntnissen über alternative Ressourcenmanagementstrategien führte. Die Integration biologischer und sozio-ökonomischer Aspekte erfasste die Komplexität des Ressourcensystems Nha Phu Lagune und seiner Nutzer. Dies beinhaltet eine Vielzahl von verschiedenen Ressourcen, Akteuren, Ebenen, Institutionen, Entscheidungsstrukturen, Livelihood Strategien, Trends und assoziierte Probleme des nachhaltigen Managements natürlicher Ressourcen.The selected study site, Nha Phu Lagoon is characterized by massive degradation of coastal fishery resources. As a result rural livelihoods in coastal communities are threatened. Since household decisions concerning resource use are influenced by several factors, a multi-sectoral approach is necessary. A multi-sectoral approach enables to comprehend the complexity and diversity of the resource system and its users. Integrated natural resources management (INRM) is one multi-sectoral research approach that aims to develop innovative and flexible management forms to manage natural resources in a more sustainable way. The applied INRM-approach is characterized through strong interdisciplinarity and participation. Interdisciplinary means that socioeconomic and institutional aspects, e.g. resource-user groups and existing legal arrangements, are combined with biological as well as production system aspects, e.g. mangrove reforestation as well as aquaculture or gear-fishing techniques. For a period of six months participatory action research following an integrated natural resource management approach was carried out visiting 12 fishing villages around Nha Phu Lagoon. The inherent ‘learning cycle’ in participatory action research generates knowledge in a process of reflecting on the collected data that is continuously fed back to the participants. During questionnaires, semi-structured interviews, group discussions, observations, resource mappings, and Venn diagrams reasons for the degradation of fishery resources were gathered. This information was then shared with participants, which led to new insights as well as alternative resource management strategies. The integration of biological and socioeconomic aspects identified the complexity of the coastal fishery resource system Nha Phu Lagoon and its users. This includes a multitude of different resources, actors, levels, institutions, decision-making structures, livelihood strategies, trends, and associated problems in the sustainable management of the natural resources

Dive to survive: effects of capture depth on barotrauma and post-release survival of Atlantic cod (Gadus morhua) in recreational fisheries

Atlantic cod (Gadus morhua) caught in recreational fisheries are commonly released, often with barotrauma after rapid decompression. Mouth-hooked, non-bleeding cod kept in a floating net pen showed mortalities ≥40% when angled from >50 m depth, likely because of cumulative stress from ongoing barotrauma and exposure to warm surface water. In a natural setting, however, cod have the opportunity to descend after release and are not restricted to the surface. In a follow-up study, 97.8% of similarly selected cod managed to dive following immediate release, whereas 2.2% were floaters. No mortality was observed for divers kept in cages, which were lowered to capture depth for 72 h. While the floaters would likely have died in a natural setting, no mortality was observed when they were recompressed and kept at capture depth for 72 h. The occurrence of swim bladder ruptures, swollen coelomic cavities, venous gas embolisms, and gas release around the anus was significantly influenced by capture depth (range 0–90 m). A supplementary radiology study showed inflated swim bladders in 87% of the cod after 72 h, and most barotrauma signs had disappeared after 1 month. This study encourages investigation of survival potential for physoclistous species when high mortalities are assumed but undocumented. Matching natural post-release and containment environment is essential in the experimental setup, as failure to do so may bias survival estimates, particularly when a thermocline is present. Assuming minimal predation, short-term mortality of cod experiencing barotrauma is negligible if cod submerge quickly by themselves and are otherwise not substantially injured. Survival of floaters may be increased by forced recompression to capture depth. Sublethal and long-term impacts of barotrauma remain to be studied. To ensure that cod have sufficient energy to submerge, anglers are encouraged to avoid fighting the fish to exhaustion and to minimize handling before release