Now showing items 1-10 of 18
Ocean Acoustic Waveguide Remote Sensing (OAWRS) of marine ecosystems
(Journal article; Peer reviewed, 2009-12-03)
Ocean Acoustic Waveguide Remote Sensing (OAWRS) has recently been shown to be capable of instantaneously imaging and continuously monitoring fish populations over continental shelf-scale areas, covering thousands of km2. ...
Toward a Global Ocean Ecosystem Mid-trophic Automatic Acoustic Sampler (MAAS)
(Journal article; Peer reviewed, 2009-05-26)
Despite their huge biomass and pivotal role, the mid-trophic levels of marine ecosystems are not generally subject to systematic monitoring. Data from such monitoring is crucial for parameterizing, validating, and constraining ...
Towards the acoustic estimation of jellyfish abundance
(Journal article; Peer reviewed, 2005-06-23)
Acoustic target strengths (TSs) of the 2 most common large medusae, Chrysaora hysoscella and Aequorea aequorea, in the northern Benguela (off Namibia) have previously been estimated (at 18, 38 and 120 kHz) from acoustic ...
Lateral-aspect target strength measurements of in situ herring (Clupea harengus)
(Journal article; Peer reviewed, 2009-07)
Surveys of schooling herring with the new multi-beam sonar (Simrad MS70) pose new challenges when converting the echo energy to estimates of biomass. Since the sonar projects horizontally, data and models of lateral-aspect ...
Behavior of individual mesopelagic fish in acoustic scattering layers of Norwegian fjords
(Journal article; Peer reviewed, 2008-05-22)
Mesopelagic acoustic scattering layers (SLs) in 2 fjords were studied from a stationary research vessel. Diel vertical movements of SLs were assessed by hull-mounted transducers, while in situ behavior of individuals ...
Acoustic observations of jellyfish in the Namibian Benguela
(Journal article; Peer reviewed, 2001-01-26)
Multi-frequency acoustic data (18, 38 and 120 kHz) were collected in conjunction with pelagic trawl sampling for gelatinous macrozooplankton during a cruise to the Namibian Benguela in September 1999. Sampling focused ...
Acoustic resonance determination of the rigidity modulus
Behavioral responses of herring (Clupea harengus) to 1–2 and 6–7 kHz sonar signals and killer whale feeding sounds
(Journal article; Peer reviewed, 2009-01)
Military antisubmarine sonars produce intense sounds within the hearing range of most clupeid fish. The behavioral reactions of overwintering herring (Clupea harengus) to sonar signals of two different frequency ranges ...