| Effects of Macrofauna on Acoustic Backscatter from the Seabed: Field Manipulations in West Sound, Orcas Island, WA, USA |
15 JUN 2001 |
26 pages |
| Authors:
Robert F. Self; Patrick A. Hearn; Peter A. Jumars; Darrell R. Jackson; Michael D. Richardson; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS MARINE GEOSCIENCES DIV
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 | Previous observations with a bottom-mounted, radially scanning sonar (BAMS) at 40 kHz suggested that macrofaunal activities influence low-angle, acoustic backscatter from seafloor sediments. In order to test that possibility experimentally, we measured and modeled time series of backscatter strength at both 40 and 300 kllz prior to manipulation and then introduced several macrofaunal species at Imown abundances to randomly selected locations within the ensonified area. We worked in West Sound, ... |
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| Biological Time Scales in Acoustic Backscatter from Littoral Bottom Boundary Layers |
MAY 2001 |
3 pages |
| Authors:
Peter A. Jumars; UNIV OF WASHINGTON SEATTLE SCHOOL OF OCEANOGRAPHY
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| We used time-series analysis with data from acoustic instruments, i. e., TAPS (Tracor Acoustic Profiling System) and BAMS and XBAMS (two versions of APL-UW's bottom-mounted sonar system) from several different localities. We supplemented acoustic data with trap samples and plankton tows timed to capture specimens to allow us to identify causes of acoustic events. In addition, we characterized bacterial and biopolymer coverage of sediments because of the potential effects of ... |
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| Vibrational Sensing in Benthic Invertebrates |
12 OCT 1999 |
3 pages |
| Authors:
Peter A. Jumars; UNIV OF WASHINGTON SEATTLE SCHOOL OF OCEANOGRAPHY
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| This grant funded completion of a number of studies on the effects of fluid motion on small planktonic organisms. It documented the response of some benthic marine invertebrates to prolonged vibrational stimuli at 50-200 Hz, perhaps indicative of energetic, bottom boundary-layer turbulence. It showed that vibrational artifact and flow intensity generally covary in laboratory flumes used for behavioral studies of animals. Most importantly, data analyzed ... |
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| Digestive Kinetics Determines Bioavailability of Pollutants |
19 APR 1999 |
5 pages |
| Authors:
Peter A. Jumars; Lawrence M. Mayer; UNIV OF WASHINGTON SEATTLE DEPT OF OCEANOGRAPHY
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| We assayed digestive capabilities of marine deposit feeders (animals that eat sediments) by using fluorescently tagged substrates and contact-angle measurements of surfactancy. Polychaetes on average showed higher enzyme activities and surfactancy than echinoderms. We found that surfactants produced by deposit feeders substantially enhance their abilities to solubilize hydrophobic pollutants such as polycyclic aromatic hydrocarbons (PAHs). Amounts solubilized were consistent with incorporation into micelles of the surfactant. Kinetics of PAH uptake ... |
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