By Charles R. (Bob) Hitz Blog # 38 Jan. 25, 2016
I had been waiting patiently for the skipper to give the command to retrieve the trawl after an hour of towing it along the bottom, hoping it would not hang up on an unknown obstruction and would yield a catch. This was my first opportunity to observe and be involved in working a trawl catch in unexplored offshore waters, under the eyes of chief scientist Al Pruter. There were only two scientists aboard the vessel, Al and myself, for this part of the trip.
I was aboard the research vessel John N. Cobb on the second half of exploratory cruise
number 47 to Queen Charlotte Sound, B.C. Canada. In the article by H.E. Crowther entitled “Exploratory Fishing” he writes; “The primary functions of exploratory fishing are to search unexplored waters – especially offshore waters – for new fishing grounds” (1). Prior to when I went out on the Cobb in August, 1960 the exploratory group had worked out a method of determining whether there were any tows in the untrawlable areas that commercial fishermen suggested we explore. First run a series of sounding transects to determine the character of the bottom, then drag a chain over areas suggested as being trawlable by the sounder and finally, replace the chain with a commercial otter-trawl net and fish over those grounds on which the chain was successfully pulled, evaluating the commercial potential of the ground fish present.
The waters off the coast of British Columbia had been part of the fishing grounds of the U. S. trawl fleet for years before the Magnuson-Stevens Act became law in 1976 and the 200 mile conservation zone was established. The Western Flyer was part of the trawl fleet that fished Queen Charlotte Sound in late ‘50s and early ‘60s. Some commercial trawl fishermen had pointed out areas off the tip of Vancouver Island that were untrawlable, wanting them to be explored by the Cobb.
Once we arrived on the grounds on August 17, 1960, the first thing was to set haul #45 to determine what species were found there. We were to duplicate haul #44 made in the first half of the cruise when the puckering string came undone, the catch was lost before it could be brought aboard and there wasn’t time to complete another tow. I was waiting to see what was in this catch and I became excited when the fish came aboard in one lift of the cod end and was released into the checker.
The first thing the biologist must do when the catch is brought aboard is make an estimate of the total weight. A full checker holds about 3,500 lbs. and half a checker equals about 1,750 lbs. A lift or a full split is about 2,000 lbs. and the estimated weight for this haul was one ton or 2,000 pounds.
The catch is then sorted by species and a count of each made and recorded on a Data Form. A copy of the original is included here and is referred to as “Station 67”. This number was changed to #45 in the final published report (2) and a copy of Figure 7 from the report has the net hauls plotted with the new numbering system. Otter-trawl drag numbers 39 to 44 were made during the first half and numbers 45 to 56 were made during the second half.
The reason there is a difference between the original and final report numbers is that only the net hauls were used and renumbered in chronological order. All the other stations were deleted such as the sounding transects where an echo sounder was used to determine whether the bottom was soft and trawlable or hard and untrawlable as well as all the stations where a chain replaced the trawl net to reduce damage to the nets.
The skipper on the bridge has a chart laid out on the chart table and he plots the drag on it from the start to the end. He uses loran or radar to get the position along with the depth of the drag from the sounder. When making a tow he tries to follow a depth contour, in this case 85-86 fathoms. The biologist later converts the plot into latitude and longitude from the chart and records them along with any other information required.
The form is set up for exploratory fishing and the results are of interest to the fishing industry. Since this cruise was designed to find trawlable grounds, when a successful haul like 45 is made the commercial fishermen need the exact location so they can repeat it if they wish, and to know what was in the catch by weight since they are paid by the pounds landed. For example, in this haul there were 200 individual Pacific Ocean perch (POP) at an average weight of 2.5 pounds, equaling 500 pounds. Adding the weight of each of the food fish species totals 1690 pounds. Adding all the categories on the form the catch total is equal to 2091 pounds, which should equal or come close to the original estimated weight.
To my surprise there were five different species of rockfish in the catch. In the final report they would be classified as Black, Red and POP but on this form they were broken down by the scientific names except for POP (S. alutus), because there are at least 55 species of rockfish along the Pacific coast and they are difficult to differentiate.
I became so interested in this catch, helping to work up the data and to identify the rockfish, that I completely forgot about being seasick the day before on the transit along the outer coast of Vancouver Island. This was only the first day on the grounds, but a presage of the rest of the trip.