Monitoring the acoustic ecology of the shelf break of Georges Bank, Northwestern Atlantic Ocean: New approaches to visualizing complex acoustic data

Velocities were obtained from unreversed, refracted arrivals on analog records from a 48‐channel, 3.6-km hydrophone cable (3.89 km from the airgun array to the last hydrophone array). Approximately 200 records were analyzed along 1500 km of ship track on Georges Bank, northwest Atlantic Ocean, to obtain regional sediment velocity distribution to a depth of 1.4 km below sea level. This technique provides nearly continuous coverage of refraction velocities and vertical velocity gradients. Because of the length of the hydrophone cable and the vertical velocity gradients, the technique is applicable only to the Continental Shelf and the shallower parts of the Continental Slope in water depths less than 300 m. Sediment diagenesis, the influence of overburden pressure on compaction, lithology, density, and porosity are inferred from these data. Velocities of the sediment near the water‐sediment interface range from less than 1500 m/sec on the north edge of Georges Bank to 1830 m/sec for glacial deposits in the northcentral part of the bank. Velocity gradients in the upper 400 m range from [Formula: see text] on the south edge of the bank to [Formula: see text] on the north. Minimum gradients of [Formula: see text] were observed south of Nantucket Island. Velocities and velocity gradients are explained in relation to physical properties of the Cretaceous, Tertiary, and Pleistocene sediments. Isovelocity contours at 100-m/sec intervals are nearly horizontal in the upper 400 m. Isovelocity contours at greater depths show a greater difference from a mean depth because of the greater structural and lithological variation. Bottom densities inferred from the velocities range from 1.7 to [Formula: see text] and porosities range from 48 to 62 percent. The most significant factor controlling velocity distribution on Georges Bank is overburden pressure and resulting compaction. From the velocity data we conclude that Georges Bank has been partially overridden by a continental ice sheet.

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The Spreading Message in a Noisy World: Song Behavior and Acoustic Ecology in Humpback Whales (Megaptera novaeangliae), from the Southwestern Atlantic Ocean

Advances in Marine Vertebrate Research in Latin America - Coastal Research Library ◽

10.1007/978-3-319-56985-7_15 ◽

2017 ◽

pp. 407-440

Author(s):

Marcos R. Rossi-Santos

Keyword(s):

Atlantic Ocean ◽

Megaptera Novaeangliae ◽

Humpback Whales ◽

Southwestern Atlantic ◽

Acoustic Ecology ◽

Southwestern Atlantic Ocean

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Evaluating the Efficacy of Acoustic Metrics for Understanding Baleen Whale Presence in the Western North Atlantic Ocean

Frontiers in Marine Science ◽

10.3389/fmars.2021.749802 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nicole Pegg ◽

Irene T. Roca ◽

Danielle Cholewiak ◽

Genevieve E. Davis ◽

Sofie M. Van Parijs

Keyword(s):

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

Supervised Machine Learning ◽

Integrative Approach ◽

Data Sets ◽

Good Prediction ◽

Acoustic Data ◽

Activity Intensity ◽

Detection Software

Soundscape analyses provide an integrative approach to studying the presence and complexity of sounds within long-term acoustic data sets. Acoustic metrics (AMs) have been used extensively to describe terrestrial habitats but have had mixed success in the marine environment. Novel approaches are needed to be able to deal with the added noise and complexity of these underwater systems. Here we further develop a promising approach that applies AM with supervised machine learning to understanding the presence and species richness (SR) of baleen whales at two sites, on the shelf and the slope edge, in the western North Atlantic Ocean. SR at both sites was low with only rare instances of more than two species (out of six species acoustically detected at the shelf and five at the slope) vocally detected at any given time. Random forest classification models were trained on 1-min clips across both data sets. Model outputs had high accuracy (>0.85) for detecting all species’ absence in both sites and determining species presence for fin and humpback whales on the shelf site (>0.80) and fin and right whales on the slope site (>0.85). The metrics that contributed the most to species classification were those that summarized acoustic activity (intensity) and complexity in different frequency bands. Lastly, the trained model was run on a full 12 months of acoustic data from on the shelf site and compared with our standard acoustic detection software and manual verification outputs. Although the model performed poorly at the 1-min clip resolution for some species, it performed well compared to our standard detection software approaches when presence was evaluated at the daily level, suggesting that it does well at a coarser level (daily and monthly). The model provided a promising complement to current methodologies by demonstrating a good prediction of species absence in multiple habitats, species presence for certain species/habitat combinations, and provides higher resolution presence information for most species/habitat combinations compared to that of our standard detection software.

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Species-specific patterns of distribution and abundance of the cryptic copepods Pseudocalanus moultoni and P. newmani on Georges Bank (NW Atlantic Ocean) during spring 1995–2012

Continental Shelf Research ◽

10.1016/j.csr.2020.104242 ◽

2020 ◽

Vol 208 ◽

pp. 104242

Author(s):

Kayla E. Crouch ◽

Leocadio Blanco-Bercial ◽

David E. Richardson ◽

Nancy J. Copley ◽

Peter H. Wiebe ◽

...

Keyword(s):

Atlantic Ocean ◽

Georges Bank ◽

Patterns Of Distribution ◽

Species Specific

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Dissolved zirconium and hafnium distributions across a shelf break in the northeastern Atlantic Ocean

Geochimica et Cosmochimica Acta ◽

10.1016/s0016-7037(96)00246-3 ◽

1996 ◽

Vol 60 (21) ◽

pp. 3995-4006 ◽

Cited By ~ 61

Author(s):

L.V. Godfrey ◽

W.M. White ◽

V.J.M. Salters

Keyword(s):

Atlantic Ocean ◽

Shelf Break ◽

Northeastern Atlantic Ocean ◽

Northeastern Atlantic

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New record of Thalia cicar van Soest 1973 (Urochordata: Thaliacea) in the Equatorial Atlantic

Biota Neotropica ◽

10.1590/s1676-06032008000300009 ◽

2008 ◽

Vol 8 (3) ◽

pp. 99-104

Author(s):

Xiomara Franchesca García Díaz ◽

Lucia Maria de Oliveira Gusmão ◽

Sigrid Neumann-Leitão

Keyword(s):

Atlantic Ocean ◽

New Record ◽

Sao Paulo ◽

Shelf Break ◽

São Paulo ◽

Equatorial Atlantic ◽

Bottom Waters ◽

Break Area ◽

Subtropical Species ◽

Potential Use

Thalia cicar van Soest 1973 (Urochordata, Thaliacea) is considered a tropical-subtropical species, registered in the Atlantic Ocean at latitudes between 7-34º S and 6-32º N. This work enlarges the occurrence of this species for Equatorial Atlantic waters. The specimens were found in a shelf break area of the Brazilian northeastern (07º 50'-07º 70' S and 34º 23' W) during the expedition JOPS-II (Joint Oceanographic Projects II) in March 1995; and, in São Pedro e São Paulo arquipelago (0º 55' N and 29º 20' W) in May and June, 2005. These two areas are characterized by the presence of local upwelling that induces the ascent of bottom waters rich in nutrients, generating areas of larger productivity than the typically oligotrophic Equatorial Atlantic waters. The new occurrence of Thalia cicar reported in this work can be related to these more productive waters of Equatorial Atlantic. The species that is most commonly found in the Atlantic Ocean is T. democratica, and the lack of past records of T. cicar might have been caused by the taxonomic difficulties determining of the solitary and aggregate zooids of these two species. This work suggests the potential use of the ratios among tunic lengths as an additional character to differentiate T. cicar and T. democratica oozooids.

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Redescription of Pennella instructa Wilson, 1917 (Copepoda: Pennellidae) from the swordfish (Xiphias gladius L.)

Canadian Journal of Zoology ◽

10.1139/z86-107 ◽

1986 ◽

Vol 64 (3) ◽

pp. 727-730 ◽

Cited By ~ 5

Author(s):

W. E. Hogans

Keyword(s):

Atlantic Ocean ◽

Georges Bank ◽

Northwest Atlantic ◽

Lateral Horn ◽

Xiphias Gladius

Two specimens of Pennella instructa Wilson, 1917 are described from swordfish (Xiphias gladius L.) collected off Georges Bank in the northwest Atlantic Ocean. This mesoparasitic copepod is characterized by two lateral horn holdfasts extending posteriorly parallel to the neck, distinct groups of papillae on the anterior end of the cephalothorax, and five-segmented and setose first antennae.

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Beyond autism: Challenging unexamined assumptions about social motivation in typical development

Behavioral and Brain Sciences ◽

10.1017/s0140525x18002273 ◽

2019 ◽

Vol 42 ◽

Author(s):

Karen Bartsch ◽

David Estes

Keyword(s):

Social Interest ◽

Social Motivation ◽

Typical Development ◽

Typically Developing ◽

New Approaches

Abstract In challenging the assumption of autistic social uninterest, Jaswal & Akhtar have opened the door to scrutinizing similar unexamined assumptions embedded in other literatures, such as those on children's typically developing behaviors regarding others’ minds and morals. Extending skeptical analysis to other areas may reveal new approaches for evaluating competing claims regarding social interest in autistic individuals.

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