Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Aquaculture and Fisheries
Juvenile Finfish And Blue Crab Stock Assessment Program Bottom Trawl Survey Annual Data Summary Report Series Volume 1992, Christopher F. Bonzek, Patrick J. Geer, James A. Colvocoresses, Robert E. Harris
Juvenile Finfish And Blue Crab Stock Assessment Program Bottom Trawl Survey Annual Data Summary Report Series Volume 1992, Christopher F. Bonzek, Patrick J. Geer, James A. Colvocoresses, Robert E. Harris
Reports
This report summarizes data collected by the Virginia Institute of Marine Science (VIMS) monthly trawl survey cruises for January-December 1992. The trawl survey is a long term, broad scope monitoring program. Its primary goal is to produce annual indices of juvenile (young-of-year) abundance of commercially, recreationally and ecologically important marine and estuarine finfish and crustaceans. The objective is to provide indices of sufficient accuracy and precision for both immediate resource management needs and long-term understanding of environmental influences on fishery resources. A second important product of this effort is the documentation and monitoring of habitat utilization by juveniles and smaller …
Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh
Effects Of Moonlight And Daylight On Hydroacoustic Estimates Of Pelagic Fish Abundance, Chris Luecke, Wayne A. Wurtsbaugh
Watershed Sciences Faculty Publications
To determine how moonlight and daylight affect hydroacoustic estimates of fish abundance, we used a dual-beam transducer and echo integration to survey pelagic fish (primarily Bonneville ciscoes Prosopium gemmifer) in Bear Lake, Utah and Idaho. During the new moon, the fish were dispersed (not schooling) below the thermocline, chiefly at the depths of 10–20 m. At full moon, they were dispersed but much closer to the bottom, where they were difficult to detect. Acoustic estimates offish density and biomass during full moons were approximately 50% of values derived during new moons. A diel survey during a new moon indicated that …