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Author Topic: Lower Fraser River Recreational Hook and Release Sockeye Mortality Pilot Study 2  (Read 644 times)

wildmanyeah

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Not sure why but this study was recently published on PSF website.  Does anyone have any info on the full study?


https://www.psf.ca/sites/default/files/Week2summary.pdf

Subject: LOWER FRASER RIVER RECREATIONAL HOOK AND RELEASE SOCKEYE  MORTALITY PILOT STUDY 2008: SUMMARY FOR WEEK 2 — AUGUST 19 TO 23, 2008
The study restarted on Tuesday August 19 with the setup and organization of the Grassy Bar study site and the net pen site.
The following is a brief summary of results from the second study week:
>   The study averaged 10 anglers per day. Daily angler counts from Tuesday to Saturday were 13, 8, 7, 15 and 8, respectively. The largest daily catch of sockeye (21) occurred on August 19. Few fish were encountered thereafter, coinciding with declines of migrating sockeye. If the study can maintain 15 to 20 anglers per day, it should be able to acquire sufficient fish for the study. The key component will be in-river sockeye abundance.
>   The study captured and held 39 angler-caught sockeye for 24-hour observation. Daily catches from Tuesday to Saturday were 21, 1, 8, 9 and 0 (zero), respectively. There were zero (0) mortalities observed during the week. A total of 162 angler-caught sockeye have now been held for 24-hour observation with two (2) observed mortalities (1.2%).
>   Results of hooking locations were as follows:

Hooking Location   Frequency
Maxillary bone   72%
Chin - exterior   13%
Ventral snag   3%
Corner of mouth - Inside   0%
Lower jaw - Inside   0%
Upper jaw - Inside   3%
Floor of mouth   0%
Dorsal snag   3%
Unknown (hook displaced)   0%
Roof of mouth   3%
Head - exterior   0%
Eye   0%
Other - (tail)   0%
Gills   3%
Total   100%

>   Leader length ranged from 8 to 16 feet, with lengths of 12 to 14 feet predominant.
>   Angling observations recorded data on hooking location, degree of bleeding, scale loss, hook size, leader length, playing time, method of landing, and air exposure.
>   Beach seining was conducted on Wednesday August 20 and Thursday August 21 to acquire study control fish. A total of 77 sockeye were caught; 68 held in the pens, and 9
 
sacrificed for physiological sampling. No mortalities (zero) have been encountered to date on the 83 control group sockeye observed from the net pen holding over the two study periods.
In addition to sockeye, the beach seine caught and released a total of 225 jack chinook and 35 adult chinook. Three (3) sturgeon were caught and immediately released; one (1) adult approximately 1.5m in length, and two (2) juveniles less than 20 cm each in length. All of the adult and jack chinook were wild, as indicated by intact adipose fins.
>   Data collection during the week included a full spectrum of environmental data including
air/water temperatures, current flow, and dissolved oxygen levels. Distinct environmental data was collected at the angling site as well as the net pen site. Significant rainfall during the week resulted in elevated river levels and a modest decline in water temperature.
>   Net pen sampling included the application of numbered Floy tags to all sockeye. The tags
will allow all angling, beach seine, and release variables to be assessed for individual sockeye.

Here is a brief summary of results from the first week:
>   The study averaged 12 anglers per day. Daily angler counts from Tuesday to Saturday
were 16, 7, 11, 10 and 16, respectively). The largest daily catch of sockeye (41) occurred on the day of fewest anglers. Angler efficiency was also correlated to where anglers were fishing. The optimal catch site was the bottom portion of the bar, which can effectively support < 20 anglers. If we can be consistent and maintain 15 - 20 anglers per day, we should be able to acquire sufficient fish for the study. The key component will be sockeye abundance.
>   The study captured and held 123 sockeye for 24 hour observation. Daily counts from
Tuesday to Saturday were 30, 41, 17, 20 and 15, repsectively). We witnessed two (2) mortalities during the week with both fish caught on August 6. One of the sockeye mortalities had been foul-hooked above the left pectoral fin and the hook had penetrated the body cavity and pierced either the heart or liver. The necropsy identified the body cavity as full of blood. The second mortality presented no obvious cause of death.
Results of hooking locations were as follows:

Hooking Location   Frequency
Maxillary bone   60%
Chin - exterior   13%
Ventral snag   7%
Corner of mouth - Inside   5%
Lower jaw - Inside   4%
Upper jaw - Inside   2%
Floor of mouth   2%
Dorsal snag   2%
Unknown (hook displaced)   2%
Roof of mouth   1%
Head - exterior   1%
Eye   1%
Other - (tail)   1%
Total   100%
 
>   Beach seining was conducted on Wednesday August 7 to acquire study control fish. A total of 21 sockeye were caught; 15 held in the pens, and 6 sacrificed for physiological sampling. The poor performance of the beach seine confirmed the low abundance of sockeye. As the day progressed, beach seine sets were conducted based on the success of real-time angling.
>   Leader length ranged from 8 to 16 feet, with lengths of 12 to 14 feet predominant.
>   Data collection during the week included a full spectrum of environmental data including air/water temperatures, current flow, and dissolved oxygen levels. Distinct environmental data was collected at the angling site as well as the net pen site.
>   Angling observations recorded data on hooking location, degree of bleeding, scale loss, hook size, leader length, playing time, method of landing, and air exposure.
>   Net pen sampling included the application of numbered Floy tags to all sockeye. The tags will allow all angling and release variables to be assessed for individual sockeye

« Last Edit: January 24, 2018, 03:29:27 PM by wildmanyeah »
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chris gadsden

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I filmed a few videos of this study here is one.https://youtu.be/vnUwWLMYjbM

wildmanyeah

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I filmed a few videos of this study here is one.https://youtu.be/vnUwWLMYjbM

Thanks so much for the video Chris. You seem to have a lot of insider information on this file. Do you have more details of the study and any idea why the PSF would just post it recently?

I found this study, can't get full access to it tho.

"influence of Postcapture Ventilation Assistance on Migration Success of Adult Sockeye Salmon following Capture and Release"


http://www.tandfonline.com/doi/full/10.1080/00028487.2015.1031282?scroll=top&needAccess=true

Also found

"Globally, 60 percent of fish caught by recreational anglers are released and many of those anglers use manual release techniques they believe will help the fish survive.

 http://www.cbbulletin.com/434341.aspx

However, according to a recent study, many of those fish will live just a short period of time. The delayed mortality rate can be as high as 35 percent and, as this study determines, catch and release is deadly for female fish."

"
The study, published online June 2, 2015 in the Transactions of the American Fisheries Society, concludes that the techniques of releasing fish promoted by conservation and angling groups simply does not result in a mortality benefit for fish, at least for the tens of thousands of sockeye salmon caught and released by anglers every year in British Columbia’s Fraser River system.

 

(In 2011, recreational anglers released 62,642 sockeye salmon out of 145,291 caught in the Fraser River system, a 43 percent release rate.)

 

“This was the first study to examine the extent to which different recovery techniques help fish to recover from catch-and-release fishing events,” said co-author Dr. Steven Cooke, Associate Professor of Environmental Science and Biology at Carlton University in Ottawa. “Given that so many anglers spend time recovering fish after capture, we expected recovery would be uniformly beneficial, but that was not the case.”

 

He added that the benefits of using recovery techniques depends on the condition of the fish at release, with the “greatest benefits for the fish that were in the roughest shape.”"
« Last Edit: January 29, 2018, 11:01:11 AM by wildmanyeah »
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chris gadsden

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Sorry I donot.