Northwest Fisheries Science Center

The Main Deck

Acoustic and trawl adventures in the Northeast Pacific

This portal tracks the research and sea-going activities of the Fisheries Engineering and Acoustic Technologies (FEAT) Team from NOAA¿s Northwest Fisheries Science Center.  Follow us as we use acoustics, trawling, and oceanographic sampling to learn about the Northeast Pacific Ocean.

Back deck of Bell M. Shimada
Acoustic echogram of hake
trawl catch

Adult hake

By Sandy Parker-Stetter, NWFSC
January 27, 2017

After our weather delay, the Winter Survey got right back to business and found adult hake!

Echogram - Adult hake
Echogram of Adult hake

The echogram (38 kHz, -69 dB threshold) shows time along the top (x-axis), with vertical lines at 30-minute intervals. The left side is 3:00 pm local time and the right is 6:30 pm. Along the side (y-axis) is depth below the surface. Depths of 0-600 m are shown, with a horizontal line at 300 m.

The black rectangle shows the hake aggregation that was the target of our trawling. As trawl targets go, this wasn’t super dense (or it would have had more orange and red color in it). But, we fished it, confirmed it was hake, and got adult fish ~45 cm in length.

Bash and hake
FRAM Division Coordinator, Jeff Bash, out of his natural habitat. Photo credit: Brittney Bair, OSU

As we were wrapping up the trawl, the sun began to set and everything in the water column headed for the surface. The hake in the echogram head upward and then disperse from their layer - not so easy to fish when you can’t find them! Above the hake are three other bands, likely lanternfish or other small fish or squid, and those also head for the surface as it gets dark. In the morning, we watch the opposite pattern as everyone heads down to spend their day in the deep.

Tagged: Hake, Acoustics, Winter hake research, FEAT, FRAM, Oceanography, Ecosystem, California Current Large Marine Ecosystem, CCLME, El Niño, La Niña, Climate

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July 2017
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