F5A

The study was conducted by the BC Ministry of the Environment Lands and Parks and it was specific to hooking mortality. In 1985 and 1986 they studied hooking mortality using barbed hooks with bait, barbed no bait, barbless hooks with bait, and barbless no bait. The total number of fish caught, released, and tracked was 336; of these 17 died or 5.1 percent. Use of natural bait produced higher mortality (5.6%) than artificials (3.8%). Mortality was higher with barbed hooks (7.3%) than for barbless hooks (2.9%) regardless of whether bait or artifical lure was employed.

In addition, the study also listed results from collecting steelhead for the BC brood stock program. BC collects their brood stock by hook and line and takes them to collection facilities for spawning. From 1981 to 1987, a total of 4,051 fish were caught on 11 different BC streams and 177 died for a hooking mortality of 3.6%.

As to your comment regarding the high post-spawn survival, you're probably correct in comparison to many WA streams. The Keogh River is a small coastal stream only a few miles in length. This may contribute to higher post-spawn survival. The streams small size makes it particularly useful for research. The Ministry has a weir across then entire stream at about river mile 0.5 and counts every fish that enters the stream and every fish that exits. The study conducted in 85 and 86 were not estimates or calculated results, but actual counts of survival/mortality.

A few other remarks:

The study was conducted by fisheries biologists who were likely more adept at handling fish, so were likely easier on the fish than a lot of sporties (although they also tagged the fish before release, which sporties don't do!). They were using standard steelhead gear, so I imagine they were playing fish sufficiently so that they could be handled and tagged (particularly since half the fish were caught barbless), but not until exhaustion. I would say most sporties do this. They were catching the fish very low in the stream, so energy and fat content were probably pretty high; this probably differs from where many sporties catch their fish and may cause different levels of hooking mortality. Its also worth pointing out though, that super newby fish caught very low or those that race upstream lose their scales very easily, making them more vulnerable to handling stress, much more so than a fish thats been in freshwater even a couple of days.

Given potential differences between bios and sporties catching fish and where fish are caught in basins, the hooking mortalities experienced in the BC studies could be viewed as conservative, but the data are as hard as they come. Which is why most biologists assume a hooking mortality for winter steelhead of 10 percent or less. This seems pretty reasonable.