Sorry for the essay but I’ve discussed this topic in length many times over and have seen both sides of the story/equation on this one.
I actually worked on a dragger (the Viking Enterprise) for 6 months back when I was 20, here is what I observed. We had a fisheries observer on board the entire time, but that was likely due to the size of the ship. I am not in favor of this kind of fishery, in our waters it is generally going to be unsustainable in my opinion, that being said it will likely remain as it has around the rest of the world so its better to put pressure on the system to become more effective and sustainable, than to try and outright shut it down.
We were targeting Hake, Arrowtooth flounder and Pollock, but we had quotas for other groundfish to maximize profitability and minimize bycatch. This included most Shelf and Slope rockfish species and sablefish
The amount of bycatch can vary widely, and this was also notable when the captains changed out on trips, one would get very little to insignificant bycatch while the other pulled up a net of only bycatch. As an example while fishing midwater trawl off the north end for pollock, the first captain filled the boat (500,000lbs) with pollock in less than a week, with only about 2 fish totes of mixed bycatch. The next captain hauled the net 3 times full of spiny dogfish (80,000 lbs to a net) which were all discarded as bycatch, most of which were dead or would die soon after. And we had to return to port for fuel and unload after two weeks with the boat less than half full.
The bottom trawls are a different story, and in my opinion should not be allowed whatsoever for any species on the pacific coast. The bottom trawls or actual dragging, were targeting Arrowtooth flounder, which in all practical cases are INEDIBLE!! Why we eve bother to fish for these is beyond reason. They literally dissolve when you try to cook them, they don’t taste good and are generally laden with parasites. Now although the bycatch generally increased it wasn’t like an amazing jump in percentage, maybe a jump of 3-5% as a best guess, however now the bycatch included skates, halibut, sharks, sculpins, chimaera, sablefish, all kinds of rockfish, nearly anything that lived near bottom. Not to mention these rip up the bottom and smash all sorts of organisms into oblivion. There was less variation in catch makeup when captains switched for this fishery.
Now on the subject of Chinook and Salmon in general, these were a rare sight when we were fishing, it was probably the least common bycatch for us. And this was to a point that when a chinook hit the deck for the first time I was on board, the bosun RAN to get the fisheries observer, mainly because he wanted it for the dinner, which is not allowed but most observers let the crews eat the fish they bring up for dinner on the boat if they want to, which may total half a dozen fish over two weeks. It really was not as common as you would expect if you look at the numbers in that report the total catch is greater than 100 million Kg, so to make the math easy lets just say and even 100. The total bycatch of chinook is 117,102 kg so lest round it to 117k. that means the overall bycatch of chinook is 0.001% of the landed catch. Or for every 1000 fish caught there would be 1 chinook statistically is seem irrelevant HOWEVER, the total 2019 chinook salmon commercial retention was 117,593 fish (not kilograms, actual individual fish) and if we say the average chinook weighed an average of 7kg (probably a bit low) that would total 825,659 kg of fish. Compare that to the total bycatch and you can see how this is a problem. There is a solution and it would involve Human intervention, the sounders on these boats are very good, the fish they target inhabit very specific zones in the water column. It would take the willingness of the vessel owners and operators to watch for potentially vulnerable species inhabiting shallower waters when setting or hauling the trawls and make shifts to avoid them if possible. Also running smaller trawls and hauling them more frequently could lower the mortality rate of bycatch. Possibly even have a small recovery tank on board for species such as salmon which are robust enough and don’t have swim bladder issues, and given a chance can recover and be released.
There are a few problems in general for this fishery in general, first bycatch retention for the most part is not allowed, most European countries allow for full bycatch retention which makes sense since anything returned to the ocean after this kind of netting will likely die. Then there needs to be a change to the quota system to account for these bycatch retentions that would assign a premium tonnage to the bycatch to act as a sort of penalty, this dissuades captains intentionally targeting more profitable bycatch. This way the boats can make a profit and the fish doesn’t go to waste.
We also need to really look at the profitability vs environmental damage in regard to all fisheries not just exclusively at trawling. However Dragging should be near the top of the list as we all know most of the populations of groundfish can be overfished very rapidly. This may require the elimination of large trawlers as they can scoop up an entire school of fish which effectively eliminates that run and genetic diversity.
Reallocation of government funds are in all honesty very necessary, The DFO does what they can with what they have. We all know there is a major lack of oversight of both commercial and recreational fisheries, I have not once in my life (38 years of it) been stopped and had someone check for a license or check my catch. They simply don’t have resources to hire people to do continuous and comprehensive studies and monitor impacts and populations accurately, nor have the finances to hire enough enforcement officers to make any difference.
2019 salmon retention data
Test Fisheries
www-ops2.pac.dfo-mpo.gc.ca