Olav Rune Godø
Institute of Marine Research, P. O. Box 1870
N-5024 Bergen, Norway
Source - Journal of Northwest Atlantic Fishery Science, Volume 23: 105-131
The need for quality data from fisheries abundance surveys for the rational management of the world's major fisheries resources has been steadily increasing. The limitation of fish resources and the heavy exploitation pressure put on these resources have forced the industry to change and adjust strategy accordingly and to develop new and more efficient fishing gears and fish finding instruments. Earlier, the assessment and management was based on models which utilized data primarily from the fishing fleet. However, the lack of continuity and stability caused by the continuously changing fishing techniques, creates uncertainty for the management decisions based on catch data.
The experience from 30 to 40 years of scientific surveys has shown that this source of information also involves a great deal of uncertainty. The need for improvements in survey methodology is crucial for improving assessments of all major fish stocks. The great limitation in improving the reliability of survey based abundance estimates is the variability and inconsistency of the data collected at sea. In the development of acoustic surveys the policy has been to continuously improve the technical equipment. New technology has been introduced when sufficient calibration exists so as not to seriously disrupt the time series. In contrast, standardization has been the most dominant philosophy in bottom trawl survey history. Therefore new technology and information has been difficult to implement in survey equipment and procedures.
The main challenge in the next century will be to update survey methodology with state-of-the-art technology. Further, combining information from different sources will be the greatest challenge for new research, for example combining data from acoustic and bottom trawl surveys. Underwater observation technology (video, laser, electronic tags, automatic underwater vehicles etc.) will greatly improve our insight on the efficiency and variability of standard survey methodologies. A major difficulty will be to distinguish between and make decisions on the need for additional monitoring and/or modelling based on new technology and information.
Language - English
Publisher - Northwest Atlantic Fisheries Organization (NAFO), Dartmouth, N.S., Canada
Publication Date - October 1998
Publication Type - Journal Article