FIELD ROCKFISH KEY

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China Rockfish from Orr’s Guide, p. 32

By: Charles R. (Bob) Hitz       Blog 41                                             Nov 9, 2016

I was aboard the John N. Cobb one evening in August, 1960 during my first exploratory trip when we anchored alongside Triangle Island, the westernmost island of the Scott Islands group located off Cape Scott at the northwestern end of Vancouver Island, Canada.  It gave the crew a chance to sport fish and I was struck by the variety of rockfish caught.  I still remember seeing my first China Rockfish (S. nebulosus), its blue-black body color with a vivid yellow strip down the side.  The intensity of the different colors displayed by rockfish when they came out of the water was amazing.

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Sally Collins holding a Chinook Salmon Collins Photo

When we were on the grounds and had a successful tow, we’d sort the trawl-caught fish into groups.  One of them, rockfish, could be comprised of one or more of the 53 species found in the northeastern Pacific Ocean.  They were recorded as either red or black with the exception of one red species, Pacific Ocean perch (POP) S. alutus, which had recently became commercially important.  I was fascinated by the different color patterns of the rockfish.  They were not as vivid as sport-caught fish but were still very noticeable.

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Bruce Collins holding a red Vermilion Rockfish, Collins Photo

Bruce Collins, a family friend, loves to sport fish and makes a trip with his family to thewest side of Vancouver Island at least once a year seeking chinook and silver salmon.  They are very successful and he showed me a picture of his wife, Sally, holding a chinook salmon she caught.  He mentioned they caught a number of rockfish and showed me photos which reminded me of those fish I saw many years ago – the wonderfully vivid colors when they came out of the water alive.  He returned them to sea so they could continue to live.  We know they are slow-growing and that many rockfish live to be 50 to 100 years old.  There are pictures of Bruce holding a red Vermilion Rockfish (S. minialus), and a red striped species called the Tiger Rockfish (S. nigrocinctus) held by their son Scott.  The photo of the subdued brown one Bruce is holding is difficult to identify from only the picture because of the dark brown blotch on the rear part of the gill cover indicates it is a Brown Rockfish, (S. auriculatus) whereas the color streak on the 3rd dorsal spine which is found on the Copper Rockfish, (S. caurinus).  It could be a hybrid, which are known to exist in Puget Sound where there is apparent hybridization of quillback (S. maliger), copper and brown rockfishes, making species identifications especially difficult (1).  If they had appeared in the 1960 trawl catch when I was aboard the Cobb, the red-banded one as well as the red one would be piled into the red category, and the brown one would go into the black.

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Scott Collins holding a tiger Rockfish, Collins photo

 

Starting about the time I was hired we were required to identify each species in the catch, and with so many different rockfish we needed a key to identify some of them correctly.  Keys in those days were based on different characteristics of individual species and the two keys we used were Clemens and Wilby’s “Fishes of the Pacific Coast of Canada” (2) and Phillips’ “A Review of the Rockfishes of California” (3).  In 2008 after the Cobb was decommissioned I actually found a copy of the Clemens and Wilby book we had used.  On the inside of the cover in my handwriting I found, “Exploratory Fishing – U.S. Fish & Wildlife” written when I was on a trip in 1960.

Both keys used the “true and false” method for identifying a fish.  If we came across one we weren’t sure of we would go to Clemens and Wilby’s key, starting with Item 1 which reads “1 (6) Mouth in a circular sucking disk; jaws absent; nostril, 1, median.”  If the fish we were trying to identify was a rockfish the statement would be false, so we skipped, down to item 6 which states; “6 (1) Mouth not in circular sucking disk; jaws present; nostrils, 2”.  True, so then we could go to item 7, answering each of the descriptions which matched or skipping until we reached item 268 (315), which states; “Spines in anal fin, III, conspicuously large, stout, second and third usually longer and stronger than first; rays, 5 to 9,” which is true and we have reached Family Scorpaenidae – Rockfishes.  Then we could go down one line to item 269, answer those questions and continue down the lines until we had identified the rockfish we held.

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Bruce Collins holding a Hybrid Rockfish Collins Photo

If we couldn’t name the rockfish in the Clemens and Wilby key which listed 24 species of Sebastodes in Canadian waters, we would turn to Phillips’ key which lists 49 species in California waters.  His key is only for the family of Scorpaenidae – Rockfish, and the print was even smaller.

You can imagine trying to identify a fish by following a key like this on an open deck in rain and wind, the vessel rolling and pitching from ocean swells and chop.  Inspecting fish while wearing bulky foul weather gear and trying to read fine print was extremely difficult and keeping the book dry almost impossible.  If you got out of the weather and went down into the hold where the scientific lab was located and could concentrate on the small lines of text I, for one, would become seasick and have to get back up onto the deck.  I thought there had to be a better way for identifying rockfish in the field.

In those days the keys were put together in the depository where the preserved specimens

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Hitz’s Key,page 5, Hitz Drawing

were kept, and measurements and counts were made on individual specimens.  Most were preserved in formaldehyde, which leached out natural color.  Color photos of each species would have been the ideal way to produce a field key, but the cost of printing a colored pamphlet was prohibitive and there weren’t many colored photos of rockfish available.

Once I was back at the office I selected the 53 species that I believed existed along the northeastern coast of the Pacific, placed each name on a half-size sheet of typing paper and then divided those into 4 categories by body color; Striped Rockfish, Black Rockfish, Red Rockfish and White/Red-Spotted Rockfish, putting those identification tabs along the outside margins of the page.

Deciding that a pen and ink scale drawing of the profile of each fish was the way to go, I used Phillips’ publication (3) as a guide to make the drawing, using the black and white photo he had of individual fish to get the outline and the measurements and counts that he listed for each species to make sure of the accuracy of the drawing.

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Hitz’s Key pages 36 & 37, Hitz Drawing

Once that was completed, one or two characteristics that separated an individual from the rest of the group were selected, condensed to a few words and placed on the page next to its profile.  A line was drawn from the text to the profile so that the identifying characteristic that identified the fish could be easily recalled in the field.  The page was finalized by placing the tabs that represented the individual fish on the margins of the page.

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Orr’s Guide page 8

One of the four colored tabs which matched the color of the fish was put on the outer edge of the paper.  Head spines were used to separate the rockfish in the old keys, they were divided into two groups, weak or strong head spines, placed at the top of the page and one was selected to match the fish.  A drawing of the top of the head showing the location of the 8 pairs of head spines was also added to the page.  The head spines present for an individual fish were note on its page.  At the bottom there were three tabs representing the relationship of the 2nd anal fin spine to the 3rd that the old keys used to help separate the rockfish.  They were longer than 3rd, as long as 3rd, and shorter than 3rd.  The tab that represented the fish aided identification.

A number of drafts were tried in the field until the final one was laid out on an 8.5” x 11” standard sheet of paper.  This was divided in half, placing one fish on the right side and another on the left and folded to make a 5.5” x 8.5” pamphlet.  It could be put in a pocket and used when there was a question about the identification of a group of rockfish within the trawl catch.  If the pamphlet got wet and slimy it would dry out with time and if not, you could get another one.  It was finally published as the U. S. Department of Interior’s Fish and Wildlife Service Circular 203 in March 1965 (4) with a total of 53 species of Sebastodes listed, and IT WORKED.

After NOAA was formed in 1970, the observer program expanded and individuals were trained to go out on foreign vessels to monitor those catches, taking a circular with them.  It was modified in 1977 and again in 1981, adding 4 species for a total of 57 species, and the generic name was changed to Sebastes instead of Sebastodes.  Additional copies were made.

In October 1998 Orr, Brown and Baker published a new guide, which improved the old circular by replacing many of the drawings with color profile photos of each species of rockfish.  In the introduction Orr states; “Primarily designed as an aid in field identification, this guide follows the basic format of Hitz’s (1965) ‘Field Identification of the Northeastern Pacific Rockfish (Sebastodes),’ the first guide to successfully use color as a major characteristic to identify species of Sebastes.”  In August 2000 a second revision (5) was made and almost all the drawings were replaced with color photos, making the identification of individual fish easier.  Those publications listed a total of 66 species of Sebastes in the northeastern Pacific Ocean increasing the count by 13 from the 53 that I used in 1965.

 

  • Love, M. S., M. Yoklavich, & L. Thorsteinson (2002). The Rockfishes of the Northeastern Pacific.  The Regents of the University of California, 404 p.  (p. 144, caurinus, description and p. 129, S. auriculatus description)
  • Clemens, W. A., & G. V. Wilby (1961). Fishes of the Pacific Coast of Canada.  Fisheries Research Board of Canada, Bulletin No. 68, 443 p.
  • Phillips, J. B. (1957). A Review of the Rockfishes of California (Family Scorpaenidae).  California Fish and Game, Fish Bulletin No. 104, 158 p.
  • Hitz, C. R. (1965). Field Identification of the Northeastern Pacific Rockfish (Sebastodes). U.S. Fish & Wildlife Service Circular 203.
  • Orr, J. W., M. A. Brown & D. C. Baker (2000). Guide to Rockfishes (Scorpaenidae) of the Genera Sebastes, Sebastolobus, and Adelosebastes of the Northeast Pacific Ocean, Second Edition.  NOAA Technical Memorandum NMFS-AFSC-117, 47 p.
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About finleyc

I'm a writer and a historian of science. I'm interested in the intersection of science and policy in the oceans, and especially around fishing.
This entry was posted in Exploratory Fishing Base, fisheries science, Fishing, History of Science, History of Technology, Maritime History, Ocean fishing, Pacific Fishing History Project, R/V John N. Cobb, Rosefish, Sebastes rockfish, World History. Bookmark the permalink.

One Response to FIELD ROCKFISH KEY

  1. Orlay Johnson says:

    I was a NOAA observer in the late 70s-early 90s and still have a copy of the Field ID of NE Pacific Rockfish full of many notes from tours on Soviet ships. I can still remember sitting in my bunk pouring over it trying to figure out what kind of rockfish I had seen that day. It was a life saver for me.

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