Behavior-dependent selectivity of yellowtail flounder (Limanda ferruginea) in the mouth of a commercial bottom trawl

-To improve the efficiency of a commercial bottom trawl for catching yellowtail flounder (Limanda ferruginea), we studied the behavior of individuals in the middle of the trawl mouth. Observations were conducted with a high-definition camera attached at the center of the headline of a trawl, during the brightest time of day in June 2010 off eastern Newfoundland. Behavioral responses were quantified and analyzed to evaluate predictions related to fish behavior, orientation, and capture. Individuals showed 3 different initial responses independent of fish size, gait, and fish density: they swam close to (75%), were herded away from (19%), or moved vertically away from (6%) the seabed. Individuals primarily swam in the direction of initial orientation. No fish were oriented against the trawling direction. Fish in the center of the trawl mouth tended to swim along the bottom in the trawling direction. Only individuals that were stimulated to leave the bottom were caught. Individuals in peripheral locations within the trawl mouth more often swam inward and upward. Fish that swam inward were twice as likely to be caught. Fish size, gait, and fish density did not influence the probability of capture. A trawl that stimulates yellowtail flounder to orient inward and leave the bottom would increase the efficiency of a trawl

Strategic Learning Skills of Walden Students: Highlighting the Resources

To be successful, students need awareness of their learning skills, with guidance provided to help them focus on building needed skills. Strategic learning skills of incoming Walden University students, undergraduate through doctoral levels in all colleges, are being assessed. Immediate individualized feedback linked to targeted resources within Walden is provided while accumulating data for developing evidence-based resource materials for all Walden learners.https://scholarworks.waldenu.edu/symposium2019/1028/thumbnail.jp

The response of mesopelagic organisms to artificial lights

Though mesopelagic fish respond to natural light (e.g., diurnal vertical migration), few studies have looked at how they respond to artificial light and if artificial lights could be used in commercial operations to improve catchability of mesopelagic fish. Here we present a preliminary study on how mesopelagic organisms respond to blue and green spotlights, as well as red and white diffuse lights in Masfjorden (Norway; max depth of 480 m). The response of organisms in each of the three sound scattering layers (SSLs) was observed when a) artificial lights were positioned in a layer or b) moved with a constant speed (generally 0.03 ms−1) towards a layer. The artificial lights were attached to a rig with a self-contained echosounder, which recorded the vertical and horizontal avoidance of organisms in each SSL to different artificial lights. Net hauls (MIC-net) and video footage confirmed that Maurolicus muelleri and siphonophores were present in the upper layer (100–150 m), while Benthosema glaciale were present in the deeper layers (∼200 m and ∼300 m to seabed). Our findings suggest that M. muelleri (SSL1) horizontally avoid blue spotlight and white diffuse light, while B. glaciale (SSL2 and SSL3) mainly avoid the same lights downwards and can be herded downwards over 250 m. Though this study should be regarded as preliminary, the observed avoidance/herding response suggests artificial lights could be applied to improve existing fish capture methods for mesopelagic fish.acceptedVersio

An acoustic method to observe the distribution and behaviour of mesopelagic organisms in front of a trawl

publishedVersio

Mass estimates of individual gas-bearing mesopelagic fish from in situ wideband acoustic measurements ground-truthed by biological net sampling

A new acoustic approach to estimate the mass of individual gas-bearing fish at their resident depth at more than 400 m was tested on Cyclothone spp.. Cyclothone are small and slender, and possibly numerically underestimated globally as individuals can pass through trawl meshes. A towed instrumented platform was used at one sampling station in the Northeast Atlantic, where Cyclothone spp. dominated numerically in net catches, to measure in situ acoustic wideband target strength (TS) spectra, i.e. acoustic scattering response of a given organism (”target”) over a frequency range (here, 38 + 50–260 kHz). Fitting a viscous–elastic scattering model to TS spectra of single targets resulted in swimbladder volume estimates from where individual mass was estimated by assuming neutral buoyancy for a given flesh density, such that fish average density equals that of surrounding water. A density contrast (between fish flesh and seawater) of 1.020 resulted in similar mass–frequency distribution of fish estimated from acoustics/model and Cyclothone spp. caught in nets. The presented proof of concept has the potential to obtain relationships between TS and mass of individual gas-bearing mesopelagic fish in general.publishedVersio

Multi-Object Tracking by Iteratively Associating Detections with Uniform Appearance for Trawl-Based Fishing Bycatch Monitoring

The aim of in-trawl catch monitoring for use in fishing operations is to detect, track and classify fish targets in real-time from video footage. Information gathered could be used to release unwanted bycatch in real-time. However, traditional multi-object tracking (MOT) methods have limitations, as they are developed for tracking vehicles or pedestrians with linear motions and diverse appearances, which are different from the scenarios such as livestock monitoring. Therefore, we propose a novel MOT method, built upon an existing observation-centric tracking algorithm, by adopting a new iterative association step to significantly boost the performance of tracking targets with a uniform appearance. The iterative association module is designed as an extendable component that can be merged into most existing tracking methods. Our method offers improved performance in tracking targets with uniform appearance and outperforms state-of-the-art techniques on our underwater fish datasets as well as the MOT17 dataset, without increasing latency nor sacrificing accuracy as measured by HOTA, MOTA, and IDF1 performance metrics

Distribution and composition of mesopelagic macroplankton and micronekton in the North-east Atlantic

acceptedVersio

Evaluating the extent of a large-scale transformation in gateway science courses

We evaluate the impact of an institutional effort to transform undergraduate science courses using an approach based on course assessments. The approach is guided by A Framework for K-12 Science Education and focuses on scientific and engineering practices, crosscutting concepts, and core ideas, together called three-dimensional learning. To evaluate the extent of change, we applied the Three-dimensional Learning Assessment Protocol to 4 years of chemistry, physics, and biology course exams. Changes in exams differed by discipline and even by course, apparently depending on an interplay between departmental culture, course organization, and perceived course ownership, demonstrating the complex nature of transformation in higher education. We conclude that while transformation must be supported at all organizational levels, ultimately, change is controlled by factors at the course and departmental levels

Deprescribing opioids in chronic non-cancer pain : systematic review of randomised trials

Background Deprescribing, the process of reducing or discontinuing unnecessary or harmful medicines is an essential part of clinical practice. Objective To evaluate the efficacy of interventions designed to deprescribe opioid analgesics for pain relief in patients with chronic non-cancer pain. Methods We searched electronic databases, including clinical trial registries, from database inception to 13th January 2020 without restrictions, and conducted citation tracking. Our systematic review included randomised controlled trials (RCTs) evaluating interventions reducing the prescription, or use of opioid analgesics in patients with chronic pain versus control. Inventions could be aimed at the patient, clinician, or both. We excluded trials enrolling patients with cancer or illicit drug use. Two authors independently screened and extracted data. Outcome follow-up timepoints were short (≤ 3 months), intermediate (> 3 but < 12 months) or long (≥ 12 months) term. Primary outcome was the reduction in opioid dose [morphine milligram equivalent (MME) mg/day]. Methodological quality was assessed using the Cochrane Risk of Bias Tool. Results We included ten patient-focused RCT interventions (n = 835; median 37 participants) and 2 testing clinician-focused interventions (n = 291 clinicians); none at low risk of bias. Patient-focused interventions did not reduce opioid dose in the intermediate term [e.g. dose reduction protocol, mean difference (MD) − 19.9 MME, 95% CI − 107.5 to 67.7], nor did they increase the number of participants who ceased their dose, or increase the risk of serious adverse events or adverse events. One clinician intervention of education plus decision tools versus decision tools alone reduced the number of opioid prescriptions (risk difference (RD) − 0.1, 95% CI − 0.2 to − 0.1), dose (MD − 5.3 MME, 95% CI − 6.2 to − 4.5) and use (RD − 0.1, 95% CI − 0.1 to − 0.0) in the long term