New Survey Techniques for Epipelagic Fish Stocks Tested

September 15, 2005
Contact: Jim Churnside

ETL has just finished a very successful field campaign to test new survey techniques for epipelagic fish stocks. The objective is to provide more accurate stock assessments at lower cost using innovative technologies like the airborne fish lidar and fixed underwater moorings, combined with more traditional techniques like fisheries acoustics and trawling from ships. ETL led a large group that also comprises researchers from NOAA Fisheries, the University of Alaska, the University of Washington, and Oregon State. ETL has also received enthusiastic support from the local fishing industry in the form of daily briefings from the spotter pilots that find fish for the fishing fleet, and catch data from the fishing boats.

While detailed results will have to wait for data analysis, we have been very successful at finding the major biomass concentrations of sardines and tracking the movements of that biomass over the 2 weeks of the experiment. Using information obtained from the spotter pilots, we have learned how to discriminate between the 3 major species of schooling fishes (sardine, anchovy, and mackerel) in this area in the data from the airborne lidar. We also have lidar data collected in very close proximity to the acoustic survey data on the ship. These data have yet to be analyzed, but discussions between the aircraft and the ship during the surveys suggest a combination of both techniques might provide a much better picture of the distribution of fish than either alone.

The results will be used to investigate the cost effectiveness of multi-platform, adaptive-survey techniques. The ETL effort was supported by the Ocean Exploration Program.

More Information

• Marine Ecological Studies at ETL