Large mesopelagic fish biomass in the Southern Ocean resolved by acoustic properties

The oceanic mesopelagic zone, 200–1000 m below sea level, holds abundant small fishes that play central roles in ecosystem function. Global mesopelagic fish biomass estimates are increasingly derived using active acoustics, where echosounder-generated signals are emitted, reflected by pelagic organisms and detected by transducers on vessels. Previous studies have interpreted a ubiquitous decline in acoustic reflectance towards the Antarctic continent as a reduction in mesopelagic fish biomass. Here, we use empirical data to estimate species-specific acoustic target strength for the dominant mesopelagic fish of the Scotia Sea in the Southern Ocean. We use these data, alongside estimates of fish relative abundance from net surveys, to interpret signals received in acoustic surveys and calculate mesopelagic biomass of the broader Southern Ocean. We estimate the Southern Ocean mesopelagic fish biomass to be approximately 274 million tonnes if Antarctic krill contribute to the acoustic signal, or 570 million tonnes if mesopelagic fish alone are responsible. These quantities are approximately 1.8 and 3.8 times greater than previous net-based biomass estimates. We also show a peak in fish biomass towards the seasonal ice-edge, corresponding to the preferred feeding grounds of penguins and seals, which may be at risk under future climate change scenarios. Our study provides new insights into the abundance and distributions of ecologically significant mesopelagic fish stocks across the Southern Ocean ecosystem

Illuminating the Living Lanterns of Antarctica

Lanternfish are a relatively small but very abundant fish. They live deep in the ocean’s “twilight” zone where there is not much light. A unique community of lanternfish live in the Southern Ocean, where they are a key part of the Antarctic food web. Lanternfish also play an important role in moving carbon from the atmosphere into the deep ocean, where it is stored. In this article, we explain current knowledge on Southern Ocean lanternfish, including how they produce their own light! We will also tell you about some mysteries surrounding lanternfish that scientists are yet to solve

Prevalence, Nature, Severity and Risk Factors for Prescribing Errors in Hospital Inpatients : Prospective Study in 20 UK Hospitals

Funding This study was funded by the General Medical Council (GMC). The study funders had no role in the study design, in the collection, analysis, and interpretation of data, in the writing of this manuscript or in the decision to submit the article for publication. Acknowledgements The EQUIP team would like to thank the following people: Members of the Expert Reference Group (Graham Buckley, Gary Cook, Dianne Parker, Lesley Pugsley and Mike Scott); Members of the Error Validation Group (Lindsay Harper, Katy Mellor, Steven Williams, Keith Harkins, Steve McGlynn, Ray George, Tim Dornan, Penny Lewis); Tribal Consulting Ltd. (Heather Heathfield, Emma Carter) for database design; Study co-ordinators at hospitals (Linda Aldred, Deborah Armstrong, Isam Badhawi, Kathryn Ball, Neil Caldwell, Vanya Fidling, Nicholas Fong, Heather Ford, Andrea Gill, Lindsay Harper, Jean Holmes, Sally James, Christopher Poole, Sally Shaw, Heather Smith, Julie Street, Atia Rifat, David Thornton, Tracey Thornton, Jane Warren, Steven Williams), and all pharmacists at the study sites who collected data for this study.Peer reviewedPublisher PD

Spatial structuring in early life stage fish diversity in the Scotia Sea region of the Southern Ocean

The fish community of the Scotia Sea is diverse and plays key roles in Antarctic food webs and biogeochemical cycling. However, knowledge of the spatial and community structure of their early life stages is limited, particularly in the region surrounding the South Orkney Islands. Here we examine the structure of the early life stage fish community in the epipelagic using data from a basin-scale survey conducted in early 2019, which sampled the top 200 m of the water column. 347 early life stage fish from 19 genera were caught in 58 hauls. A third of all specimens belonged to the genus Notolepis and the nine most common genera comprised over 90% of specimens. Cluster analysis revealed five distinct groupings, the most common were a group dominated by pelagic and shelf slope genera (Notolepis, Muraenolepis and Electrona) found mainly in oceanic waters (depth ≥ 1000 m), and a group dominated by species with demersal or benthopelagic adults (Chionodraco, Chaenocephalus and Nototheniops) found mainly in shelf waters. Bottom depth was the main environmental determinant of community structure, separating the diverse on-shelf assemblage at the South Orkneys from the less species-rich community of widespread oceanic taxa. Our results indicate the highest diversities of early life stages of endemic fish occur on the shelf and near-shelf areas. Dedicated monitoring is recommended to understand the seasonal differences in larval community assemblages and the implications of early life stages fish bycatch within the krill fishery

Acoustic backscatter data and RMT25 abundance and biomass data for Scotia Sea, Southern Ocean 2006, 2008, 2009, 2015, 2016 and 2017

This is a mixed data set held in six excel files, containing processed acoustic backscatter data, mesopelagic fish abundance and swimbladder contents from night time sampled RMT25 nets, plus net catch data for all fauna combined and dominant mesopelagic fish in night time RMT25. Acoustic backscatter data is from 6 latitudinal acoustic transects spanning the Scotia Sea, obtained during cruises JR161, JR177, JR200, JR15002 and JR15004 (two transects). Data were collected using a Simrad EK60 echo sounder at 38 kHz. The EK60 was run continuously between Stanley (Falkland Islands) and Signy (South Orkney Islands). Fish data was collected using RMT25 night time net samples from 5 cruises JR161, JR177, JR200, JR15004 and JR16003. The data set focuses on 11 species of mesopelagic fish Bathylagus species, Cyclothone species, Electrona antarctica, Electrona carlsbergi, Gymnoscopelus braueri, Gymnoscopelus fraseri, Gymnoscopelus nicholsi, Krefftichthys anderssoni, Protomyctophum bolini, Protomyctophum tenisoni, and Notolepis species. Abundance and proportion data was obtained for combined fish species, and identified by net tow and latitude. Biomass for all fauna and the 11 fish species was calculated from RMT25 night catch log data. Myctophid gas presence absence was determined from a combination of dissection, Computed Tomography and soft tissue X-ray. Funding was provided by the NERC grants NE/L002434/1 and bas010017. This data is embargoed until August 2019

How do postgraduate GP trainees regulate their learning and what helps and hinders them? A qualitative study

Contains fulltext : 108146.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Self-regulation is essential for professional development. It involves monitoring of performance, identifying domains for improvement, undertaking learning activities, applying newly learned knowledge and skills and self-assessing performance. Since self-assessment alone is ineffective in identifying weaknesses, learners should seek external feedback too. Externally regulated educational interventions, like reflection, learning portfolios, assessments and progress meetings, are increasingly used to scaffold self-regulation.The aim of this study is to explore how postgraduate trainees regulate their learning in the workplace, how external regulation promotes self-regulation and which elements facilitate or impede self-regulation and learning. METHODS: In a qualitative study with a phenomenologic approach we interviewed first- and third-year GP trainees from two universities in the Netherlands. Twenty-one verbatim transcripts were coded. Through iterative discussion the researchers agreed on the interpretation of the data and saturation was reached. RESULTS: Trainees used a short and a long self-regulation loop. The short loop took one week at most and was focused on problems that were easy to resolve and needed minor learning activities. The long loop was focused on complex or recurring problems needing multiple and planned longitudinal learning activities. External assessments and formal training affected the long but not the short loop. The supervisor had a facilitating role in both loops. Self-confidence was used to gauge competence.Elements influencing self-regulation were classified into three dimensions: personal (strong motivation to become a good doctor), interpersonal (stimulation from others) and contextual (organizational and educational features). CONCLUSIONS: Trainees did purposefully self-regulate their learning. Learning in the short loop may not be visible to others. Trainees should be encouraged to actively seek and use external feedback in both loops. An important question for further research is which educational interventions might be used to scaffold learning in the short loop. Investing in supervisor quality remains important, since they are close to trainee learning in both loops

Productivity and change in fish and squid in the Southern Ocean

International audienceSouthern Ocean ecosystems are globally important and vulnerable to global drivers of change, yet they remain challenging to study. Fish and squid make up a significant portion of the biomass within the Southern Ocean, filling key roles in food webs from forage to mid-trophic species and top predators. They comprise a diverse array of species uniquely adapted to the extreme habitats of the region. Adaptations such as antifreeze glycoproteins, lipid-retention, extended larval phases, delayed senescence, and energy-conserving life strategies equip Antarctic fish and squid to withstand the dark winters and yearlong subzero temperatures experienced in much of the Southern Ocean. In addition to krill exploitation, the comparatively high commercial value of Antarctic fish, particularly the lucrative toothfish, drives fisheries interests, which has included illegal fishing. Uncertainty about the population dynamics of target species and ecosystem structure and function more broadly has necessitated a precautionary, ecosystem approach to managing these stocks and enabling the recovery of depleted species. Fisheries currently remain the major local driver of change in Southern Ocean fish productivity, but global climate change presents an even greater challenge to assessing future changes. Parts of the Southern Ocean are experiencing ocean-warming, such as the West Antarctic Peninsula, while other areas, such as the Ross Sea shelf, have undergone cooling in recent years. These trends are expected to result in a redistribution of species based on their tolerances to different temperature regimes. Climate variability may impair the migratory response of these species to environmental change, while imposing increased pressures on recruitment. Fisheries and climate change, coupled with related local and global drivers such as pollution and sea ice change, have the potential to produce synergistic impacts that compound the risks to Antarctic fish and squid species. The uncertainty surrounding how different species will respond to these challenges, given their varying life histories, environmental dependencies, and resiliencies, necessitates regular assessment to inform conservation and management decisions. Urgent attention is needed to determine whether the current management strategies are suitably precautionary to achieve conservation objectives in light of the impending changes to the ecosystem