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Acoustic Estimates of Pelagic Ichthyomass in Lake Tanganyika with an Inexpensive Echo Sounder
Author(s) -
Chapman D. W.
Publication year - 1976
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1976)105<581:aeopii>2.0.co;2
Subject(s) - pelagic zone , echo sounding , echo (communications protocol) , environmental science , oceanography , fishery , remote sensing , geology , computer science , biology , computer network
A costly Simrad acoustical system, calibrated against fish biomass in a keep‐net, yielded internally consistent estimates of pelagic ichthyomass in Lake Tanganyika (East Africa). An inexpensive sounder (Furuno), tested alongside the Simrad system, provided information which correlated reasonably well with data from the Simrad system. I did not rigorously demonstrate accuracy of either system. Indices of abundance for the inexpensive sounder, based on depth of fish layers or schools, echogram trace area, and a subjective estimate of trace density correlated sufficiently well with commercial ring‐net catches that I could predict fishing success. The indices of fish abundance served also for studies of gross changes in fish distribution.