scholarly journals Birds of a Feather Eat Plastic Together: High Levels of Plastic Ingestion in Great Shearwater Adults and Juveniles Across Their Annual Migratory Cycle

2022 ◽  
Vol 8 ◽  
Author(s):  
Anna R. Robuck ◽  
Christine A. Hudak ◽  
Lindsay Agvent ◽  
Gwenyth Emery ◽  
Peter G. Ryan ◽  
...  
Keyword(s):  
Ground Truth ◽  
South Atlantic ◽  
Life Stages ◽  
Massachusetts Bay ◽  
Plastic Pollution ◽  
Sand Lance ◽  
Fish Prey ◽  
Type Size ◽  
Migratory Cycle ◽  
Trends Over Time

Limited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters (Ardenna gravis) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance (Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.

scholarly journals Microplastics distribution in the Eurasian Arctic is affected by Atlantic waters and Siberian rivers

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Evgeniy Yakushev ◽  
Anna Gebruk ◽  
Alexander Osadchiev ◽  
Svetlana Pakhomova ◽  
Amy Lusher ◽  
...  
Keyword(s):  
Surface Water ◽  
Surface Waters ◽  
Water Masses ◽  
The Arctic ◽  
Plastic Pollution ◽  
Siberian River ◽  
Highest Weight ◽  
Surface Samples ◽  
Atlantic Origin ◽  
Type Size

AbstractPlastic pollution is globally recognised as a threat to marine ecosystems, habitats, and wildlife, and it has now reached remote locations such as the Arctic Ocean. Nevertheless, the distribution of microplastics in the Eurasian Arctic is particularly underreported. Here we present analyses of 60 subsurface pump water samples and 48 surface neuston net samples from the Eurasian Arctic with the goal to quantify and classify microplastics in relation to oceanographic conditions. In our study area, we found on average 0.004 items of microplastics per m3 in the surface samples, and 0.8 items per m3 in the subsurface samples. Microplastic characteristics differ significantly between Atlantic surface water, Polar surface water and discharge plumes of the Great Siberian Rivers, allowing identification of two sources of microplastic pollution (p < 0.05 for surface area, morphology, and polymer types). The highest weight concentration of microplastics was observed within surface waters of Atlantic origin. Siberian river discharge was identified as the second largest source. We conclude that these water masses govern the distribution of microplastics in the Eurasian Arctic. The microplastics properties (i.e. abundance, polymer type, size, weight concentrations) can be used for identification of the water masses.

Variations in type, width, volume and carbon content of anchoveta Engraulis ringens food items during the early larval stages

2011 ◽  
Vol 91 (6) ◽  
pp. 1207-1213 ◽  
Author(s):  
A. Yañez-Rubio ◽  
A. Llanos-Rivera ◽  
L.R. Castro ◽  
G. Claramunt ◽  
L. Herrera
Keyword(s):  
Carbon Content ◽  
Single Species ◽  
Life Stages ◽  
Relative Importance ◽  
Ontogenetic Changes ◽  
Central Chile ◽  
Larval Stages ◽  
Food Items ◽  
Type Size ◽  
Engraulis Ringens

In order to determine the changes in the relative importance of different kinds of preys as larval anchoveta Engralis ringens grows, the present study reports information about feeding incidence, type, size, and carbon content estimates of preys, at the beginning of the main spawning season in mid-winter off central Chile. Our results show a mixed diet initially dominated by phytoplankton and later switching to zooplankton in older larvae. While larval anchoveta grows, they feed on preys whose widths do not vary much compared to their body length and volume. These preys might be different taxa or a single species whose body widths vary little among life stages (i.e. nauplii and copepodites). Differences in estimated carbon content were observed among food items and a marked increase in carbon consumption was observed in the larger larval sizes (>9 mm standard length). These ontogenetic changes in feeding are coincident with the increased proportion of larger preys and also with the number of preys consumed by larger larvae.

Seismic and hydroacoustic observations from recent underwater events in the South Atlantic Ocean

2020 ◽  
Vol 223 (1) ◽  
pp. 289-300 ◽  
Author(s):  
Ross Heyburn ◽  
David Bowers ◽  
David N. Green
Keyword(s):  
Atlantic Ocean ◽  
Ground Truth ◽  
South Atlantic ◽  
Acoustic Energy ◽  
South Atlantic Ocean ◽  
Charge Weight ◽  
San Juan ◽  
The South ◽  
Arrival Times ◽  
Frequency Modulations

SUMMARY To study the location and characterize two underwater events in the South Atlantic Ocean, we analyse both seismic and hydroacoustic signals. The first event (2017 November 15) occurred around 550 km east of Argentina, near the last reported position of the Argentine Navy submarine the ARA San Juan, the seafloor wreck of which was found one year later. The second event (2017 December 1) was due to an aircraft-dropped depth charge, detonated as part of the search for the ARA San Juan. We use signal arrival times and azimuths recorded at two seismic and two hydroacoustic stations to estimate epicentres for both events; our estimates were within 10 km of the ground-truth locations. We used geophysical models and databases to determine the sound-speed structure of the water and the presence of sea-ice to help interpret differences in the frequency content and dispersion of signals at the two hydrophone stations. Hydrophone signals for the 2017 November 15 event contain significant energy at high frequencies, which is inconsistent with an earthquake source. Hydrophone signals for the 2017 December 1 event show frequency modulations consistent with those expected from the known depth and explosive energy. Hydrophone signals from the 2017 November 15 event also show frequency modulations, though differences between these for the two events suggest differences in the details of the source mechanisms. Using estimates of the local seismic magnitudes, the peak pressures recorded on the hydrophones, and the known charge weight for the 2017 December 1 event, we estimate that the 2017 November 15 event had an acoustic energy release equivalent to around 428 kg of trinitrotoluene. This analysis demonstrates the importance of high-precision traveltime predictions from models of seismic and ocean acoustic velocities when analysing low-magnitude underwater events.

scholarly journals A design of a multistage recycling device for Marine plastic waste

2020 ◽  
Vol 165 ◽  
pp. 05004
Author(s):  
Duokui Fang
Keyword(s):  
Plastic Waste ◽  
Plastic Pollution ◽  
Recovery Method ◽  
Effective Implementation ◽  
Multi Stage ◽  
Collection Device ◽  
Type Size ◽  
Size Grade ◽  
And Storage ◽  
Medium Diameter

Based on the research of Marine plastic garbage recovery method, the discussion of the recovery device and the understanding of the types of ships, this paper designs a multi-stage recovery device for Marine plastic garbage. This device according to the types of the existing Marine plastic garbage and recycling requirements, effective implementation for big (more than 50 cm diameter or width), medium (diameter and width are between 5 mm ~ 50 cm) and micro (diameter or width under 5 mm) type size grade plastic debris automatic classification recycling, determined the primary barb type crawler collection device, second level network intercept type garbage collection device and the third level based on the sponge and activated carbon micro plastic collection device. Recycling and storage of Marine plastic waste to effectively address Marine plastic pollution is consistent with the MARPOL convention on the protection of the Marine environment.

Microincrements of otoliths of the Japanese sand lance Ammodytes personatus during early life stages

2002 ◽  
Vol 68 (5) ◽  
pp. 1158-1160
Author(s):  
YOUICHI TSUKAMOTO ◽  
HIROKATSU YAMADA ◽  
HIROMU ZENITANI
Keyword(s):  
Early Life ◽  
Life Stages ◽  
Early Life Stages ◽  
Sand Lance ◽  
Ammodytes Personatus

scholarly journals Using a structural root system model to evaluate and improve the accuracy of root image analysis pipelines

2016 ◽  
Author(s):  
Guillaume Lobet ◽  
Iko T. Koevoets ◽  
Manuel Noll ◽  
Patrick E. Meyer ◽  
Pierre Tocquin ◽  
...  
Keyword(s):  
Image Analysis ◽  
Root System ◽  
System Analysis ◽  
Ground Truth ◽  
Machine Learning Algorithms ◽  
Automated Image Analysis ◽  
Ground Truth Data ◽  
Image Descriptors ◽  
Type Size ◽  
Root Image Analysis

AbstractRoot system analysis is a complex task, often performed with fully automated image analysis pipelines. However, the outcome is rarely verified by ground-truth data, which might lead to underestimated biases.We have used a root model, ArchiSimple, to create a large and diverse library of ground-truth root system images (10,000). For each image, three levels of noise were created. This library was used to evaluate the accuracy and usefulness of several image descriptors classically used in root image analysis softwares.Our analysis highlighted that the accuracy of the different traits is strongly dependent on the quality of the images and the type, size and complexity of the root systems analysed. Our study also demonstrated that machine learning algorithms can be trained on a synthetic library to improve the estimation of several root system traits.Overall, our analysis is a call to caution when using automatic root image analysis tools. If a thorough calibration is not performed on the dataset of interest, unexpected errors might arise, especially for large and complex root images. To facilitate such calibration, both the image library and the different codes used in the study have been made available to the community.

Before I Die

GeroPsych ◽  
2018 ◽  
Vol 31 (3) ◽  
pp. 151-162 ◽  
Author(s):  
Qiao Chu ◽  
Daniel Grühn ◽  
Ashley M. Holland
Keyword(s):  
End Of Life ◽  
Psychosocial Development ◽  
Time Horizon ◽  
Development Theory ◽  
Life Stages ◽  
Socioemotional Selectivity Theory ◽  
Socioemotional Selectivity ◽  
Time Horizons

Abstract. We investigated the effects of time horizon and age on the socioemotional motives underlying individual’s bucket-list goals. Participants were randomly assigned to one of three time-horizon conditions to make a bucket list: (1) an open-ended time horizon (Study 1 & 2), (2) a 6-month horizon (i.e., “Imagine you have 6 months to live”; Study 1 & 2), and (3) a 1-week horizon (Study 2). Goal motives were coded based on socioemotional selectivity theory and psychosocial development theory. Results indicated that time horizon and age produced unique effects on bucket-list goal motives. Extending past findings on people’s motives considering the end of life, the findings suggest that different time horizons and life stages trigger different motives.

A Comparison of Simple Structure Rotation Criteria in Temporal Exploratory Factor Analysis for Event-Related Potential Data

Methodology ◽  
2019 ◽  
Vol 15 (Supplement 1) ◽  
pp. 43-60 ◽  
Author(s):  
Florian Scharf ◽  
Steffen Nestler
Keyword(s):  
Factor Analysis ◽  
Exploratory Factor Analysis ◽  
Simple Structure ◽  
Ground Truth ◽  
Event Related Potential ◽  
Suitable Alternative ◽  
Factor Rotation ◽  
Rotation Methods ◽  
Simple Structure Rotation ◽  
Temporal Overlap

Abstract. It is challenging to apply exploratory factor analysis (EFA) to event-related potential (ERP) data because such data are characterized by substantial temporal overlap (i.e., large cross-loadings) between the factors, and, because researchers are typically interested in the results of subsequent analyses (e.g., experimental condition effects on the level of the factor scores). In this context, relatively small deviations in the estimated factor solution from the unknown ground truth may result in substantially biased estimates of condition effects (rotation bias). Thus, in order to apply EFA to ERP data researchers need rotation methods that are able to both recover perfect simple structure where it exists and to tolerate substantial cross-loadings between the factors where appropriate. We had two aims in the present paper. First, to extend previous research, we wanted to better understand the behavior of the rotation bias for typical ERP data. To this end, we compared the performance of a variety of factor rotation methods under conditions of varying amounts of temporal overlap between the factors. Second, we wanted to investigate whether the recently proposed component loss rotation is better able to decrease the bias than traditional simple structure rotation. The results showed that no single rotation method was generally superior across all conditions. Component loss rotation showed the best all-round performance across the investigated conditions. We conclude that Component loss rotation is a suitable alternative to simple structure rotation. We discuss this result in the light of recently proposed sparse factor analysis approaches.

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