Lobster trap video: in situ video surveillance of the behaviour of Homarus americanus in and around traps

2001 ◽  
Vol 52 (8) ◽  
pp. 1125 ◽  
Author(s):  
Steven H. Jury ◽  
Hunt Howell ◽  
Daniel F. O'Grady ◽  
Winsor H. Watson III
Keyword(s):  
Time Lapse ◽  
Homarus Americanus ◽  
Low Light ◽  
Video Recordings ◽  
Video Cassette Recorder ◽  
Red Led ◽  
Sandy Habitat ◽  
Behavioural Interactions ◽  
Rocky Habitats

A lobster-trap video (LTV) system was developed to determine how lobster traps fish for Homarus americanus and how behavioural interactions in and around traps influence catch. LTV consists of a low-light camera and time-lapse video cassette recorder (VCR) mounted to a standard trap with optional red LED arrays for night observations. This self-contained system is deployed like a standard lobster trap and can collect continuous video recordings for >24 h. Data are presented for 13 daytime deployments of LTV (114 h of observation) and 4 day and night deployments (89 h of observation) in a sandy habitat off the coast of New Hampshire, USA. Analyses of videotapes revealed that traps caught only 6% of the lobsters that entered while allowing 94% to escape. Of those that escaped, 72% left through the entrance and 28% through the escape vent. Lobsters entered the trap at similar rates during the day and night and in sandy and rocky habitats. Lobsters generally began to approach the trap very shortly after deployment, and many appeared to approach several times before entering. These data confirm the results of previous laboratory-based studies in demonstrating that behavioural interactions in and around traps strongly influence the ultimate catch.

scholarly journals Pelagic deep-sea fauna observed on video transects in the southern Norwegian Sea

Polar Biology ◽  
2021 ◽  
Author(s):  
Philipp Neitzel ◽  
Aino Hosia ◽  
Uwe Piatkowski ◽  
Henk-Jan Hoving
Keyword(s):  
First Record ◽  
Observation System ◽  
In Situ Observation ◽  
Norwegian Sea ◽  
Video Recordings ◽  
In Situ Observations ◽  
Abundance And Distribution ◽  
Oceanic Food Webs ◽  
Deep Sea Fauna

AbstractObservations of the diversity, distribution and abundance of pelagic fauna are absent for many ocean regions in the Atlantic, but baseline data are required to detect changes in communities as a result of climate change. Gelatinous fauna are increasingly recognized as vital players in oceanic food webs, but sampling these delicate organisms in nets is challenging. Underwater (in situ) observations have provided unprecedented insights into mesopelagic communities in particular for abundance and distribution of gelatinous fauna. In September 2018, we performed horizontal video transects (50–1200 m) using the pelagic in situ observation system during a research cruise in the southern Norwegian Sea. Annotation of the video recordings resulted in 12 abundant and 7 rare taxa. Chaetognaths, the trachymedusaAglantha digitaleand appendicularians were the three most abundant taxa. The high numbers of fishes and crustaceans in the upper 100 m was likely the result of vertical migration. Gelatinous zooplankton included ctenophores (lobate ctenophores,Beroespp.,Euplokamissp., and an undescribed cydippid) as well as calycophoran and physonect siphonophores. We discuss the distributions of these fauna, some of which represent the first record for the Norwegian Sea.

Photoinhibition of DCMU-Enhanced Fluorescence in Lake Ontario Phytoplankton

1987 ◽  
Vol 44 (12) ◽  
pp. 2144-2154 ◽  
Author(s):  
M. Putt ◽  
G. P. Harris ◽  
R. L. Cuhel
Keyword(s):  
Vertical Mixing ◽  
Natural Populations ◽  
Bright Light ◽  
Euphotic Zone ◽  
Lake Ontario ◽  
Enhanced Fluorescence ◽  
Low Light ◽  
Light Levels ◽  
Phosphorus Status

Measurement of 1-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) enhanced fluorescence (FDCMU) suggested that photoinhibition of photosynthesis was frequently an artifact of in situ bottle incubations in Lake Ontario phytoplankton. In a seasonal study, FDCMU of all populations was depressed by bright light in an incubator. However, when the euphotic zone did not exceed the depth of the mixed layer, vertical transport of phytoplankton into either low-light or dark regions apparently allowed reversal of photoinhibition of FDCMU. Advantages of FDCMU as a bioassay of vertical mixing include rapidity of response time, ease of measurement in the field, and insensitivity of this parameter to changes in phosphorus status of the population. Because of seasonal changes in the photoadaptive response of natural populations, the rate constants and threshold light levels required to cause the response must be determined at each use if the method is to be quantitative.

Wave Breaking Dissipation in a Young Wind Sea

2014 ◽  
Vol 44 (1) ◽  
pp. 104-127 ◽  
Author(s):  
Michael Schwendeman ◽  
Jim Thomson ◽  
Johannes R. Gemmrich
Keyword(s):  
Wind Waves ◽  
Phase Speed ◽  
Field Studies ◽  
Turbulent Energy ◽  
Strength Parameter ◽  
Video Recordings ◽  
Sonar System ◽  
Wind Sea ◽  
Equilibrium Range

Abstract Coupled in situ and remote sensing measurements of young, strongly forced wind waves are applied to assess the role of breaking in an evolving wave field. In situ measurements of turbulent energy dissipation from wave-following Surface Wave Instrument Float with Tracking (SWIFT) drifters and a tethered acoustic Doppler sonar system are consistent with wave evolution and wind input (as estimated using the radiative transfer equation). The Phillips breaking crest distribution Λ(c) is calculated using stabilized shipboard video recordings and the Fourier-based method of Thomson and Jessup, with minor modifications. The resulting Λ(c) are unimodal distributions centered around half of the phase speed of the dominant waves, consistent with several recent studies. Breaking rates from Λ(c) increase with slope, similar to in situ dissipation. However, comparison of the breaking rate estimates from the shipboard video recordings with the SWIFT video recordings show that the breaking rate is likely underestimated in the shipboard video when wave conditions are calmer and breaking crests are small. The breaking strength parameter b is calculated by comparison of the fifth moment of Λ(c) with the measured dissipation rates. Neglecting recordings with inconsistent breaking rates, the resulting b data do not display any clear trends and are in the range of other reported values. The Λ(c) distributions are compared with the Phillips equilibrium range prediction and previous laboratory and field studies, leading to the identification of several inconsistencies.

Determining optimum wave velocity from sparse CMP automatically by coupling POCS interpolation and NMO correction: application to array antenna GPR data collected during in-situ infiltration test

2021 ◽  
Author(s):  
Koki Oikawa ◽  
Hirotaka Saito ◽  
Seiichiro Kuroda ◽  
Kazunori Takahashi
Keyword(s):  
Wave Velocity ◽  
Convex Sets ◽  
Numerical Study ◽  
Sand Dunes ◽  
Time Lapse ◽  
Array Antenna ◽  
Velocity Analysis ◽  
Nmo Correction ◽  
Infiltration Experiment

<p>As an array antenna ground penetrating radar (GPR) system electronically switches any antenna combinations sequentially in milliseconds, multi-offset gather data, such as common mid-point (CMP) data, can be acquired almost seamlessly. However, due to the inflexibility of changing the antenna offset, only a limited number of scans can be obtained. The array GPR system has been used to collect time-lapse GPR data, including CMP data during the field infiltration experiment (Iwasaki et al., 2016). CMP data obtained by the array GPR are, however, too sparse to obtain reliable velocity using a standard velocity analysis, such as semblance analysis. We attempted to interpolate the sparse CMP data based on projection onto convex sets (POCS) algorithm (Yi et al., 2016) coupled with NMO correction to automatically determine optimum EM wave velocity. Our previous numerical study showed that the proposed method allows us to determine the EM wave velocity during the infiltration experiment.</p><p>The main objective of this study was to evaluate the performance of the proposed method to interpolate sparse array antenna GPR CMP data collected during the in-situ infiltration experiment at Tottori sand dunes. The interpolated CMP data were then used in the semblance analysis to determine the EM wave velocity, which was further used to compute the infiltration front depth. The estimated infiltration depths agreed well with independently obtained depths. This study demonstrated the possibility of developing an automatic velocity analysis based on POCS interpolation coupled with NMO correction for sparse CMP collected with array antenna GPR.</p>

scholarly journals A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters (Homarus americanus)

10.3791/50498 ◽  
2014 ◽  
Author(s):  
Jason S Goldstein ◽  
Tracy L Pugh ◽  
Elizabeth A Dubofsky ◽  
Kari L Lavalli ◽  
Michael Clancy ◽  
...  
Keyword(s):  
Mating Success ◽  
Homarus Americanus ◽  
Noninvasive Method

scholarly journals An instrumented sample holder for time-lapse microtomography measurements of snow under advective airflow

2014 ◽  
Vol 3 (2) ◽  
pp. 179-185 ◽  
Author(s):  
P. P. Ebner ◽  
S. A. Grimm ◽  
M. Schneebeli ◽  
A. Steinfeld
Keyword(s):  
Structural Changes ◽  
Time Lapse ◽  
Temperature Gradients ◽  
Sample Holder ◽  
Experimental Characterization ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Snow Samples

Abstract. An instrumented sample holder was developed for time-lapse microtomography of snow samples to enable in situ nondestructive spatial and temporal measurements under controlled advective airflows, temperature gradients, and air humidities. The design was aided by computational fluid dynamics simulations to evaluate the airflow uniformity across the snow sample. Morphological and mass transport properties were evaluated during a 4-day test run. This instrument allows the experimental characterization of metamorphism of snow undergoing structural changes with time.

In Situ Testing Using Synchrotron Radiation Computed Tomography in Materials Research

MRS Advances ◽  
2019 ◽  
Vol 4 (51-52) ◽  
pp. 2831-2841
Author(s):  
Xinchen Ni ◽  
Nathan K. Fritz ◽  
Brian L. Wardle
Keyword(s):  
Computed Tomography ◽  
Synchrotron Radiation ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Time Lapse ◽  
In Situ Testing ◽  
Temporal Dimension ◽  
Analysis Measurement ◽  
Materials Research

ABSTRACTHigh resolution (< 1 µm) computed tomography is an attractive tool in materials research due to its ability to non-destructively visualize the three-dimensional internal microstructures of the material. Recently, this technique has been further empowered by adding a fourth (temporal) dimension to study the time-lapse material response under load. Such studies are referred to as four-dimensional or in situ testing. In this snapshot review, we highlight three representative examples of in situ testing using synchrotron radiation computed tomography (SRCT) for composites failure analysis, measurement of local corrosion rate in alloys, and visualization and quantification of electrochemical reactions in lithium-ion batteries, as well as forward-looking integration of machine learning with in situ CT. Lastly, the future opportunities and challenges of in situ SRCT testing are discussed.

In-situ disintegration of egg white gels by pepsin and kinetics of nutrient release followed by time-lapse confocal microscopy

2020 ◽  
Vol 98 ◽  
pp. 105228 ◽  
Author(s):  
Geeshani Somaratne ◽  
Francoise Nau ◽  
Maria J. Ferrua ◽  
Jaspreet Singh ◽  
Aiqian Ye ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Nutrient Release ◽  
Time Lapse ◽  
Egg White ◽  
Kinetics Of

Cross‐borehole geoelectrical time‐lapse monitoring of in situ chemical oxidation and permeability estimation through induced polarization

2020 ◽  
Author(s):  
Thue Bording ◽  
Anders Kristian Kühl ◽  
Gianluca Fiandaca ◽  
Jørgen Fjeldsø Christensen ◽  
Anders Vest Christiansen ◽  
...  
Keyword(s):  
Time Lapse ◽  
Chemical Oxidation ◽  
Induced Polarization ◽  
In Situ Chemical Oxidation ◽  
Permeability Estimation
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