Northwest Fisheries Science Center

2017 West Coast Groundfish Bottom Trawl Survey

Blog Entries for June 2017

Second Leg of the First Pass of the 2017 West Coast Groundfish Bottom Trawl Survey

By Aaron Chappell
Posted on June 19, 2017


calendar date May 19-29
 

 

Departed from Newport, Oregon on 6/1/2017. Arrived in port in Brookings, Oregon on 6/11/2017. Untrawlable habitat Aaron Chappell, FPC on F/V Last Straw 6/14/2017

The West Coast Groundfish Bottom Trawl Survey collects fishery-independent information on more than 90 groundfish species targeted commercially along the coasts of Washington, Oregon and California. The fishing gear used during the survey primarily targets fish on soft-bottom in low to moderate gradient areas, commonly referred to as “trawlable” habitat. However, we frequently encounter hard-bottom, high relief or high gradient “untrawlable” seafloor types in our randomly selected stations. In these situations, the Captain of the vessel will search our 1.5 by 2.0 nautical mile station cells for a minimum of one hour in hopes of finding trawlable habitat. Each of our stations consists of three cells: primary, secondary and tertiary, so there are three chances of finding a suitable place to tow. If all three cells are searched and no trawlable area found, we refer to that station as “Searched and Dropped,” and it is considered completed in the same sense as a successful tow.

Our charted vessels use a variety of equipment, along with the Captains’ many years of experience, to determine trawlable habitat.

On the chartered West Coast fishing vessel, F/V Last Straw, used during the first half of the survey (May – July) these include:

• Furuno 28/50 kHz echo sounder • Furuno 28 kHz paper echo sounder • Furuno CH14 sonar • Simrad EK60/70/80 echo sounder • Olex navigational and charting software 2D/3D, housing sea floor contours, relief, hardness, hang-ups, obstructions, cable crossings, and operates as an information-sharing cooperative with participating vessels. • WindPlot, Offshore Navigator and Coastal Explorer navigational software programs, housing thousands of hang-ups, obstructions, cable crossings and hard-bottom notations.

On the F/V Excalibur, a second chartered West Coast fishing vessel used during the same time period, these include:

• Furuno 1200 28 kHz echo sounder • Furuno 28 kHz paper echo sounder • Furuno 88 kHz Sonar • Simrad EK80 echo sounder • Olex navigational and charting software 2D/3D, housing sea floor contours, relief, hardness, hang-ups, obstructions, cable crossings, and operates as an information-sharing cooperative with participating vessels. • WindPlot and Globe navigational software programs, housing thousands of hang-ups, obstructions, cable crossings and hard-bottom notations.

Even with the use of the accurate and sophisticated equipment described above coupled with our Captains’ vast knowledge of West Coast habitat and fishing grounds, sometimes there is just no trawlable bottom in our cells to complete a 15-minute (approximately 1/3 to 1/2 mile) tow.

This photo depicts the F/V Last Straw’s Furuno 28/50 kHz echo sounder (bottom) outlining depth, relief, hardness, and fish aggregations, as well and Offshore Navigator software (top) showing vessel position, heading, depth contours and the many marks created during the Captain’s many years of fishing experience. (Photo credit: Aaron C. Chappell/NMFS)

 
More wheelhouse equipment from the F/V Last Straw designed to determine trawlable ground: Bottom - Furuno 28 kHz Paper Sounder commonly referred to as “The Paper Machine” (bottom), which uses a return echo gram to literally burn an image of the seafloor onto a piece of paper. These machines, while outdated, actually can produce higher-quality images than digital echo sounders, and often can show subject hangs such as medium boulders and pinnacles not easily distinguishable by its modern counterparts. Top left – Olex 2D/3D navigation and charting program monitor, outlining our station cells, bottom depth counters, hardness and relief, marks of places to avoid, and other vessels (tied in via AIS Marine Traffic program). Top right - Furuno “Ancient” CH14 Sonar which has a ‘sweeping’ arc from the transducer’s sounder moving an echo beam back and forth. This machine shows seafloor hardness, as well as fish aggregations.(Photo credit: Aaron C. Chappell/NMFS)
An image of Olex, outlining the three cells (red = primary, yellow = secondary, green = tertiary) comprising station 9345. The lines within each cell are the F/V Last Straw’s tracklines as we searched each cell for a tow. This station was a complete “Search and Drop.”
(Photo credit: Aaron C. Chappell/NMFS)

Other highlights from Leg 2:

Excalibur mid-trip fish delivery in Charleston, Oregon of about 3000 pounds. End of trip delivery in Brookings, Oregon of about 3000 pounds. 39 total stations completed: • 39 successful tows • One primary cell searched and deemed untrawlable (successful tow found in secondary cell).

Last Straw 19000 pound tow in 6:50 minutes, before hanging up on hard bottom at the west end of Heceta Bank. Catch consisted of mostly sharpchin rockfish, but also present were canary, yelloweye, bocaccio, silvergray, widow, yellowtail, greenstriped and redstripe rockfishes. Spotted a Layson Albatross offshore of Charleston, Oregon. Mid-trip fish delivery in Charleston, Oregon of about 7200 pounds. End of trip delivery in Brookings, Oregon of about 9000 pounds. 40 total stations completed: • 39 successful tows • 1 hang-up (unsuccessful tow) • 1 “Search & Drop” station, one other primary cell searched and deemed untrawlable (successful tow found in secondary cell). Our Leg 1 and 2 deliveries put us at more than 75,000 pounds of marketable fish delivered on Pass 1!


Tagged: chartered fishing vessels (f/v), first pass, second leg, 2017, west coast groundfish bottom trawl survey

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First Leg of the First Pass of the 2017 Bottom Trawl Survey

By Keith Bosley
Posted on June 15, 2017


calendar date May 19-29
 

Keith Bosley, chief scientist, leg 1, F/V Last Straw - After a busy 5 days loading gear and setting up survey equipment on the F/Vs Excalibur and Last Straw in Newport, OR, the 2017 bottom trawl survey officially got underway on the night of May 19th. Preliminary reports from other NW Center scientists who were already working at sea indicated that this could be the year of the pyrosome, which is a free-floating colonial tunicate that usually lives in the upper layers of the open ocean in warm seas. We also encountered them immediately, as our codend was full of thousands of Pyrosoma atlanticum right from the very first trawl with countless more stuck in the webbing too. They seemed to be heaviest in abundance off Oregon but we caught large amounts of them throughout the trip at almost every trawl location all the way to the Canadian border. The first leg is usually one of the “fishiest,” covering stations from the north/central Oregon Coast north to Cape Flattery, WA and this year turned out to be no exception. The F/V Last Straw had one 15-minute tow with over 9,000 lbs. of yellowtail rockfish (Sebastes flavidus) and another with more than 3,000 lbs. of petrale sole (Eopsetta jordani). So many marketable fish were caught during the first 5 days of the leg that the F/V Last Straw made a mid-trip fish delivery in Warrenton, OR and landed a total of almost 25,000 lbs. of fish! The F/V Excalibur caught its fair share as well, including one memorable 15-minute tow with greater than 20,000 lbs., almost half of that was canary rockfish (S. pinniger). Victor Simon, chief scientist onboard the F/V Excalibur, also noted an abundance of small sablefish in the catch so far this year. Other than a few days of winds in the 20-30 kt. range early in the leg, the weather was quite nice overall with several days of flat glassy seas. One final item of interest from the first leg is that a “fish chute” designed by the AFSC was deployed and tested on the F/V Excalibur. This device utilizes a camera and trigger mechanism to identify and measure fish in order to further NMFS's goal of expanding the use of electronic monitoring. The operator slides each individual fish through the chute, where a light sensor towards the end of the chute triggers the overhead camera. What it meant practically for those aboard the F/V Excalibur was that every single fish that was measured as per usual on the electronic board had to be passed through the chute too. They also processed many hundreds of fish from species that have no length protocols associated with them and some invertebrates too. It was a lot of extra work but the AFSC scientist who was along to operate the device was thrilled with the amount of information they were able to collect. This was only made possible because of the hard work and dedication of the survey scientists, Victor Simon and Doug Draper, as well as the F/V Excalibur crew too. The first leg ended back in Newport on time on the afternoon of May 29th, Memorial Day 2017.

 

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The contents of a 15-minute survey tow, primarily large Yellowtail rockfish (Sebastes flavidus) are deposited onto the back deck of the F/V Last Straw during Leg 1 of the 2017 NWFSC Bottom Trawl Survey.
(Photo credit: Keith Bosley)
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A giant wrymouth (Cryptacanthodes giganteus) was caught on the F/V Last Straw during Leg 1 of the 2017 NWFSC Bottom Trawl Survey.
(Photo credit: Keith Bosley)
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The contents of a 15-minute survey tow, primarily large Canary rockfish (Sebastes pinniger) had to be emptied onto the back deck of the F/V Excalibur during Leg 1 of the 2017 NWFSC Bottom Trawl Survey.
(Photo credit: Captain Kyle Retherford)
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Screenshots from a Simrad EK60 echosounder (left) and a Furuno echosounder (right) show what appears to be a large school of fish just off the bottom during a survey tow that wound up catching more than 9,000 lbs. of Canary rockfish on the F/V Excalibur during Leg 1 of the 2017 NWFSC Bottom Trawl Survey.
(Photo credit: Captain Kyle Retherford)

The F/V Last Straw, one of the charter vessels used for the NWFSC Bottom Trawl Survey, delivering almost 25,000 lbs. of marketable fish to processors in Warrenton, OR, mid-way through Leg 1 of the 2017 survey.

(Photo credit: Keith Bosley)

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The F/V Last Straw returning to port in Newport, Ore., at the end of the first leg of the 2017 NWFSC Bottom Trawl Survey.
(Photo credit: Keith Bosley)

Tagged: FRAM, Last Straw, Excalibur, first pass, leg 1, Newport, canary rockfish

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July 2017