| EK60 Water Column Sonar Data Collected During SH1305 |
| 2013 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake and Pacific
Sardine (SaKe 2013) (SH1305, EK60). Scientists from the Fishery Resource Analysis
and Monitoring (FRAM) division at the NOAA Fisheries Northwest Fisheries Science Center
(NWFSC), the Fishery Resources Division (FRD) at the Southwest Fisheries Science Center
(SWFSC), and the Pacific region of the Department of Fisheries and Oceans Canada (DFO)
conducted the 2013 Integrated Acoustic Survey (IAT) survey aboard the NOAA Ship Bell
M. Shimada and the Canadian Coast Guard Ship (CCGS) W.E. Ricker. Both vessels are
stern trawlers equipped for fisheries and oceanographic research. The Shimada surveyed
from 32.8°N to 51.1°N between June 9 and August 25, and the Ricker surveyed from 51.4°N
to 54.7°N between August 22 and September 11. Hake aggregations were targeted along
the continental shelf and upper slope of the entire survey area; sardine aggregations
were targeted only as far north as the northwest end of Vancouver Island. The portion
of the survey conducted with the Bell M. Shimada focuses on both Pacific sardine (Sardinops
sagax) and Pacific hake (Merluccius productus), a Joint U.S.-Canada Integrated Acoustic
and Trawl Survey of Pacific Hake and Pacific Sardine (SaKe 2013) covered the area
from the Southern California Bight (SCB), CA to north end of the Vancouver Island,
Canada. The data include here are those collected on NOAA Ship Bell M. Shimada only,
i.e. Sake 2013 data only. The survey began in the SCB, proceeded north toward Dixon
Entrance, and finished along the west side of Haida Gwaii (formerly called the Queen
Charlotte Islands). In the SCB, nine parallel line transects (spaced roughly 20 nmi
apart and oriented northeast-southwest) spanned from San Diego to Point Conception.
Approximately 30 nmi north of Point Conception, acoustic transects assumed an east-west
orientation, were spaced 10 nmi apart, and ranged from the 30-m isobath (or as close
to shore as was safely navigable) to either the 1,500-m isobath or a location 35 nmi
west of the inshore waypoint, whichever was farther offshore. (Transects north of
Vancouver Island went inshore to the 50-m isobath or as close to shore as was safely
navigable.) Transects in Dixon Entrance had a northsouth orientation. A few transects
along the west coast of Haida Gwaii were run as modified zigzags due to time constraints.
The Shimada was tasked with completing transects up to the north end of Vancouver
Island, at which point the Ricker would complete the remainder. All transects were
traversed sequentially, usually in alternating directions. When hake were detected
at the offshore end of a transect, the vessel proceeded west to the end of the hake
sign and then beyond for an additional 0.5 nmi to ensure that the end of the aggregation
was located. This protocol was in place to ensure that the interpolation algorithm
calculated the correct biomass at the offshore ends of transects. |
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