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
 

Leg 2 Volunteer Perspective - Take 3

By Heather Rippman, non-student volunteer
July 22, 2017


Transects 17-40, surveyed from July 5 to July 15, 2017, image credit Heather Rippman

None of us had ever been to sea before. We met when we boarded the Bell M. Shimada in San Francisco on the 4th of July, to begin the 2nd leg of the 2017 Joint US-Canada Integrated Ecosystem and Pacific Hake Acoustic-Trawl Survey. Before long, we’d be working as a team to efficiently collect and record catch data, even in rough seas, and learning through experience what it takes to conduct an international fishery population survey.

NOAA ship Bell M. Shimada is our hotel, restaurant, transportation, fishing vessel, and laboratory. After ten days at sea, we’d surveyed seventeen of the predefined east-west transects numbered 17-40, each around 35 nautical miles long. These cover an area offshore from roughly 300 miles of Northern California coastline from south of San Francisco almost to Eureka.

NOAA scientists Larry Hufnagle and Steve de Blois in Shimada’s acoustics lab, image credit Heather Rippman

In the acoustics lab, NOAA scientists monitor multiple sonar frequencies for signs of hake. NOAA officers, deck crew, scientists and volunteers all stand by, ready to begin fishing operations anytime during daylight hours. At night, survey technicians measure conductivity, temperature, dissolved oxygen, and chlorophyll fluorescence to depths of 500 meters. On this cruise, we’re also collecting zooplankton in a vertical net at predetermined locations, and assessing the composition of phytoplankton populations which can lead to harmful algal blooms.

While we’re at sea, there is always someone working (and there’s always someone sleeping), but the ship truly comes to life when we’re fishing. After a ten-minute marine mammal watch, the net goes in the water, together with multiple instruments and an underwater camera to record the catch. It takes longer than you might expect to send the net to the 200-400 meter depths where we typically find huge schools of hake which sometimes stretch for miles. In the lab, we wait. Often, sea birds like gulls, shearwaters, and black-footed albatross gather at the surface, also waiting for our catch. The acoustics are so accurate that it’s almost entirely hake.

As first-time volunteer marine biologists, we’ve had to learn a lot in a short period of time. Hake anatomy to identify gender and collect tissue samples. Instruments to collect and record length and weight data. And how to stay on our feet, maneuver with sharp tools, and work with sometimes temperamental instruments in a laboratory that’s always moving with the wind and waves. Two weeks ago, it took us a long time to manage even a small sample in the lab. Now we can process a typical sample of around 400 fish in just a couple of hours.

Volunteer scientists Haley Wunderlich and Garima Raheja in Shimada’s wet laboratory

Each of us approached this experience with some preconceived notions about what working at sea would be. We worried about seasickness, homesickness, long hours, or other challenges. Thankfully, we haven’t suffered any of these! And in exchange for our willingness to try something new, we’ve been rewarded with an unforgettable experience and a deeper understanding of how demanding and rewarding it is to study our oceans. Pacific hake are a significant part of the marine food web and an important commercial fishery for the US and Canada, and this research is just a small part of a much larger body of knowledge. I am deeply grateful for this experience, and for the mariners, oceanographers, and marine scientists who devote their careers to advancing our collective understanding of the oceans, the largest and most productive ecosystems on Earth.


Tagged: Hake, Acoustic Survey, Ecosystem

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