A 6,000 nautical mile round trip mission on behalf of NOAA Fisheries’ Alaska Fisheries Science Center to perform an acoustic survey of Alaska pollock in the eastern Bering Sea to be used in the formal stock assessment and to continue the existing time series. The mission was conceived as a contingency plan after NOAA’s ship-based surveys were canceled due to the COVID-19 pandemic.
The saildrones carried a calibrated EK80 38/200 kHz echo sounder, the world-standard instrument for acoustic fisheries surveys on a variety of platforms, as well as oceanographic and meteorological sensors to collect environmental data.
The survey was modeled after the planned NOAA RV Oscar Dyson survey, with some modifications: The saildrones surveyed along tracks spaced 40 nautical miles apart (Dyson tracks are typically spaced at 20 nm). The saildrones only surveyed during daylight hours, and the survey was paused if wind speeds were greater than 25 knots due to potential degradation of data.
The vehicles were deployed from San Francisco in May, completed the survey in late July, and arrived back in San Francisco in early October to deliver the raw data after nearly five months at sea.
All three vehicles functioned as expected, and the resulting data set will be used by the Fisheries Management Council to inform the sustainable management of the Alaska pollock fishery.
The 2020 Alaska pollock survey is Saildrone’s seventh mission in the Arctic. This mission is an example of how Saildrone’s unique capabilities can be a valuable tool to provide information at a time or in a region where conventional surveys are not possible.
“I think this is the first time that data from a USV are used in a formal stock assessment. This mission shows that Saildrone can do this operationally—reliably, quickly, and in the timeline required. This wasn’t a demonstration of what we could do in the future. We did this now.”
Alex De Robertis, fisheries biologist at NOAA Fisheries and project lead for the Alaska Fisheries Science Center (AFSC)
Each of three vehicles sailed 2,000 nautical miles each way between Saildrone HQ in Alameda, CA, and the survey area in the eastern Bering Sea, for a total of 6,000 nm sailed (transit + survey).