According to the “social intelligence hypothesis,” species with complex social interactions have
more sophisticated communication systems. Giant otters (Pteronura brasiliensis) live in groups
with complex social interactions. It is likely that the vocal communication of giant otters is more
sophisticated than previous studies suggest. The objectives of the current study...
Between 1999 and 2009, autonomous hydrophones were deployed to monitor seismic activity from 16° N to 50° N along the Mid-Atlantic Ridge. These data were examined for airgun sounds produced during offshore surveys for oil and gas deposits, as well as the 20 Hz pulse sounds from fin whales, which may...
This field trip consists of two geologic tours. On Tour 1, the Tertiary sedimentary rocks exposed along the Yaquina River between Newport and Toledo, Oregon, will be examined. This tour will start at the mouth of Yaquina Bay where Miocene sedimentary rocks are exposed and will proceed generally eastward and...
An alongshore wind stress is applied at the eastern boundary of an ocean model, and its effects on the structure of the circulation in the ventilated pycnocline are studied. The offshore surface Ekman flow associated with such a wind is taken to be balanced by onshore geostrophic transport distributed over...
The energy ratio mapping algorithm (ERMA) was developed to improve the performance of
energy-based detection of odontocete echolocation clicks, especially for application in environments
with limited computational power and energy such as acoustic gliders. ERMA systematically
evaluates many frequency bands for energy ratio-based detection of echolocation clicks produced
by a...
The hypothesis that sounds produced by odontocetes can debilitate fish was examined. The effects of simulated odontocete pulsed signals on three species of fish commonly preyed on by odontocetes were examined, exposing three individuals of each species as well as groups of four fish to a high-frequency click of a...
Sonar techniques were used to quantitatively observe foraging predators and their prey simultaneously in three dimensions. Spinner dolphins foraged at night in highly coordinated groups of 16–28 individuals using strict four-dimensional patterns to increase prey density by up to 200 times. Herding exploited the prey’s own avoidance behavior to achieve...
The target strength as a function of aspect angle were measured for four species of fish using dolphin-like and porpoise-like echolocation signals. The polar diagram of target strength values measured from an energy flux density perspective showed considerably less fluctuation with azimuth than would a pure tone pulse. Using detection...
In 2009 two calibrated acoustic recorders were deployed in polar waters of the North Atlantic to study the seasonal occurrence of blue, fin, and sperm whales and to assess current ambient noise levels. Sounds from these cetaceans were recorded at both locations in most months of the year. During the...
This study presents the first target strength measurements of Dosidicus gigas, a large squid that is a key predator, a significant prey, and the target of an important fishery. Target strength of live, tethered squid was related to mantle length with values standardized to the length squared of −62.0, −67.4,...
Remote autonomous ecological acoustic recorders (EARs) were deployed in deep waters at five locations around the island of Kauai and one in waters off Ni'ihau in the main Hawaiian island chain. The EARs were moored to the bottom at depths between 400 and 800 m. The data acquisition sampling rate...
Acoustic backscattering strength is often used as an index of biomass; however, the relationship between these variables has not been directly validated. Relationships were investigated between acoustic cross section at 200 kHz, measured as part of a previous study, and measured values of length, biovolume, dry weight, ash-free dry weight,...
Acoustic methods are frequently used to monitor endangered marine mammal species. Advantages of acoustic methods over visual ones include the ability to detect submerged animals, to work at night, and to work in any weather conditions. A relatively inexpensive and easy-to-use acoustic float, the QUEphone, was developed by converting a...
Fluctuations of the low frequency sound field in the presence of an internal solitary wave packet during the Shallow Water ’06 experiment are analyzed. Acoustic, environmental, and on-board ship radar image data were collected simultaneously before, during, and after a strong internal solitary wave packet passed through the acoustic track....
Vocalizations of Indo-Pacific humpback dolphins (Sousa chinensis) in west Hong Kong waters were described from 12 recordings in 2010. A broadband hydrophone system recorded sounds. Vocalizations were characterized as broadband click trains, burst pulses, and narrowband frequency modulated sounds, including whistles generally similar to those of some other delphinid cetaceans....
The characteristics of acoustic echoes from six species of deep-dwelling (up to 400 m) Hawaiian Lujanid snappers were determined by backscatter measurements at the surface. A broadband linear frequency-modulated signal and a short dolphinlike sonar signal were used as the incident signals. The fish were anesthetized and attached to a...
Broadband simulated dolphin echolocation signals were used to measure the ex situ backscatter properties of mesopelagic boundary community MBC in order to gain a better understanding of the echolocation process of spinner dolphins foraging on the MBC. Subjects were captured by trawling with a 2-m-opening Isaacs-Kidd Midwater Trawl. Backscatter measurements...
The biosonar system of dolphins and porpoises has been studied for about 5 decades and much has
been learned [Au,W.W. L. )1993). The Sonar of Dolphins (Springer, New York)]. Most experiments
have involved human-made targets; little is known about odontocetes’ echolocation of prey. To
address this issue, acoustic backscatter from...
A 200-kHz echosounder modified to digitize the envelope of the received echoes directly into a computer was used to measure the ex situ target strength (TS) of live animals from the Hawaiian mesopelagic boundary community as a function of animal size, tilt and roll angle, and biological classification. Dorsal aspect...
Although field-collected recordings typically contain multiple simultaneously vocalizing birds of different species, acoustic species classification in this setting has received little study so far. This work formulates the problem of classifying the set of species present in an audio recording using the multi-instance multi-label (MIML) framework for machine learning, and...
Groups of spinner dolphins have been shown to cooperatively herd small prey. It was hypothesized that the strong group coordination is maintained by acoustic communication, specifically by frequency-modulated whistles. Observations of groups of spinner dolphins foraging at night within a sound-scattering layer were made with a multibeam echosounder while the...
Preliminary results are presented from an analysis of mid-frequency acoustic transmission data collected at range 550m during the Shallow Water 2006 Experiment. The acoustic data were collected on a vertical array immediately before, during, and after the passage of a nonlinear internal wave on 18 August, 2006. Using oceanographic data...
The target strengths and swimbladder morphology of six snapper species were investigated using broadband sonar, x rays, and swimbladder casts. Backscatter data were obtained using a frequency-modulated sweep ~60–200 kHz! and a broadband, dolphinlike click ~peak frequency 120 kHz! from live fish, mounted and rotated around each of their three...
A broadband sonar system and digital camera with strobe lights were mounted on a vertically profiling frame with a depth sensor. The echo strengths and densities of animals within individual mesopelagic boundary community patches were investigated as a function of depth. Time and distance from shore were also investigated. Simultaneous...
The Tertiary geologic evolution of the Oregon and Washington continental margin was molded by episodic periods of convergence between the Pacific oceanic plates and the North American plate. This margin is the site of a deep basin that is floored by Paleocene to lower Eocene oceanic crust and contains more...
The purpose of this study of the Lyons flora is to determine the age and paleoecology of the flora through the examination and identification of the fossil plant species of the flora. The plant fossils comprising the Lyons flora were collected from a locality in the upper Thomas Creek area,...
"It is the purpose of this paper, through a brief review of the history of Astoria, to construct a framework of the physical history of the city, to place each published geologist in his correct historical setting within the city, and to reestablish his locales so as to be presently...
(1) Field mapping and biostratigraphic data indicate that the Yamhill Formation overlies and is younger than the Tyee Formation; interfingering of the two formations is not indicated. (2) Stewart's correlation of the Yamhill Formation with the Sacchi Beach member of the Tyee was based on incomplete knowledge of the range...
The purpose of this paper is to give some account of the fossil shark faunas of Oregon. This has been, at best, only introductory to the more than 5,000 specimens now being studied by the author. Many of the genera are listed in Figure 2, but species determinations have not...
The platinum-group metals have been the subject of considerable discussion in the news media over the past few months, particularly because of their projected use as catalysts in automobile engines. Metals Week of August 27 shows that platinum commands a price of $176.00 per ounce, as compared to $150.00 per...