
%0 Journal Article
%A Elliott, NG 
%A Kloser, RJ 
%T Use of acoustics to assess a small aggregation of orange roughy, <I>Hoplostethus atlanticus</I> (Collett), off the eastern coast of Tasmania
%J Marine and Freshwater Research
%D 1993/06/01
%V 44
%N 3
%P 473-482
%K 
%R https://doi.org/10.1071/MF9930473
%U https://www.publish.csiro.au/paper/MF9930473 
%X A relatively small aggregation of orange roughy (Hoplostethus atlancticus) was located in April 1989 off the eastern coast of Tasmania. A Simrad EK400 (38 kHz) scientific echo-sounder was used to survey the aggregation over a period of eight days, during which time the aggregation was commercially fished. The aggregation was confined to an area of approximately 4 km2, with the dimensions of the aggregation varying within and between days. High densities of orange roughy were located near the bottom on some days and more than 24 m off the bottom on others. Average fish densities during the survey and an estimate of the extremes of densities (fish m-3) are presented. Estimates of the original biomass of this aggregation as obtained from acoustic data and commercial catch-and-effort data are compared, and the mean target strength of the population is estimated. 
