Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Entire DC Network
The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello
The Use Of Acoustics To Resolve Nightly Excursions Of Hyperbenthos, Heather U. Abello
Electronic Theses and Dissertations
Acoustic analysis of die1 vertical migration in the Darnariscotta River estuary, Maine, showed a fairly regular nightly increase in biovolume (mm3 m'3) of organisms in the water column, presumed to be due to emergence, the entry of hyperbenthic organisms into the water column. Timing of these events was significantly correlated with time of sunset and time of sunrise for more than 50% of the dates where emergence and re-entry could be identified, between June and October 2002. Emergence traps indicate that the mysid shrimp, Neomysis americana, is the predominant migrator. Daily fluctuations in irradiance influence the timing of emergence fiom …
Tidal Modulation Of Nocturnal Vertical Migration From The Benthos: A High-Resolution Acoustic Analysis, Leslie E. Taylor
Tidal Modulation Of Nocturnal Vertical Migration From The Benthos: A High-Resolution Acoustic Analysis, Leslie E. Taylor
Electronic Theses and Dissertations
Emergence-trap sampling has shown that several species living primarily on or in the sediment emerge nightly into the water column. This behavior was investigated using acoustic and traditional sampling methods. A TRACOR acoustic profiler, TAPS, was mounted on the sea bottom, looking upwards in approximately 10 m of water in the Damariscotta River estuary, Walpole, Maine. TAPS emits high-frequency (265-3000 kHz) sonar pulses and each minute measures backscatter from 12.5-cm range bins in the water column. TAPS data showed a distinct increase in backscatter in the water column most evenings, beginning around or after dusk and terminating before dawn. The …