Spey Pages banner

1 - 18 of 18 Posts

·
Internet Scientist
Joined
·
1,302 Posts
Thanks Rick for posting this. I suspect you'll get pushback based on previous threads. For me, I used to take pics, but then, after a while, how many "Hey look at me, I caught a big fish, ain't I special" pics become kind of monotonous (and worthless). Of course I caught a fish, I'm a fisherman LOL.

How was the OP this year?
 

·
Registered
Joined
·
889 Posts
http://0101.nccdn.net/1_5/190/35d/1d9/Richard_MEC_12.pdf

Here is the actual study. One thing to consider is that Atlantic Salmon are not Steelhead. Steelhead are not Atlantic Salmon. Some, none, most, or all of the data may or may not apply. QC's salmon environment is different from Russia's and Spain and Scotland and so on.

Is the grip-n-grin lifting itself responsible for the reduced spawning success? Putting pressures on body parts that simply does not naturally occur? Or just air exposure after being exercised to exhaustion?
 

·
Registered
Joined
·
2,735 Posts
Discussion Starter #4 (Edited)
Paul - just there for a week in Feb and it was low and clear with few fish around but got to have dinner with John McMillan and Shane Anderson which was an awesome experience.

The recent past floods sure pushed stuff around - a number of the good runs from before are just gone and tons of wood stacked on the banks!!!

I have an old article I found back in the late 80s or early 90s - a study by R.A. Ferguson and B.L. Tufts of Queen's University in Ontario on catch and release impacts on rainbow trout and the findings indicated 28% survival with exposure of 60 seconds; 63% survival with exposure of 30 seconds; and 88% survival with no exposure. Have not tracked down the actual study but have always taken this to heart - true or not I think there is enough research out there to indicate exposure isn't good
 

·
Registered
Joined
·
2,735 Posts
Discussion Starter #5
I am not convinced that the information in that release is biased or incorrect.

I don't think anyone is really suggesting that 2 seconds will have a significant impact but 10 seconds might. I would also suggest that the majority of photos taken of fish out of the water resulted in exposure of much more than 2 seconds.
 

·
Registered
Joined
·
889 Posts
Read the study. Based in the wild and not hatchery. It simply says that Atlantic salmon (in that particular river system) removed from the water and up to 10 seconds lose reproductive success. It grows with time removed from the water. And the size of the fish being angled. Bigger fish do worse. And the water temps when the fish is being angled/released have a large impact. Talks about females chasing off less suitable males (the ANTI hatchery). Not minding the precocious parr that sneak in to fertilize. On and on and on.

Boring: Yes.

But it shows that the best odds of a fish not only surviving but being the most capable (of angled fish, as angled fish are less capable across the board if the study is correct) to produce young.

Now it needs to be repeated.
 

·
Registered
Joined
·
453 Posts
Fish pics always look better when the fish is wet, and I feel like that is even more of an aesthetic argument than anything. Grip and grins all look the same.
 

·
Registered
Joined
·
2,735 Posts
Discussion Starter #8
Wayvik
I think Inland posted link to the Atlantic salmon study
Regarding using wild fish for hatchery eggs- while better, still has significant inherent problems!
Best
Rick
 

·
Banned
Joined
·
690 Posts
3...2...1............

Just be a matter of moments methinks...that is, for the apologists to come out of the woodwork Rick.
No doubt hear from the "cull crowd" in NB again.

Here's a fish pic...

 

·
Registered
Joined
·
1,147 Posts
Here are the nuts and bolts of the studies for those who don't want to go to the link and read the whole thing







Impact of catch and release
This study demonstrated that C&R salmon represented
20% of the multi-sea-winter population and were one
of the parents for 22% of the genotyped offspring,
hence playing an important role in the reproductive
output of the whole population. Our results thus con-
firm the role played by released salmon in the observed
higher redd and parr density that followed the inception
of C&R fishing on the Ponoi River in Russia and
on the Alta River in Norway (Whoriskey et al. 2000;
Thorstad et al. 2003). Thus, C&R is an effective conservation
and management tool towards maintaining the
socio-economic benefits from recreational fishing while
ensuring a minimal impact on the exploited population,
pending appropriate practices (see below). In Canada,
annual economic value for wild Atlantic salmon has
been estimated at $255 million and 3872 full-time
equivalent jobs are directly created annually because of
wild Atlantic salmon, most of which (86%) are related
to recreational fishing (ASF 2011). Furthermore, in this
study, as well as in other previous studies (Whoriskey
et al. 2000; Thorstad et al. 2003), a small proportion
(namely, 5%, 11% and 4%) of salmon were caught and
released more than once in the fishing season, thus
increasing the value of each fish and the economic
benefits of C&R.
At an individual scale, if we exclude from the analysis
the five C&R salmon that did not pass through the
fish ladder, C&R salmon had the same probability of
reproduction as noncaught salmon. On the other hand,
when taking the fish that did not pass the ladder into
account, C&R impaired access to reproduction of multisea-winter
salmon, reducing their chances of mating by
12%. Several reasons may explain why these salmon
never crossed the dam. Indeed, although all except one
were reported to be in excellent condition, these salmon
could have died or aborted migration as a result of
C&R. However, these salmon could also have come in
the first pools of the river as visitors before returning to
the sea. This is plausible based on migrant detection in
other Atlantic salmon studies (Jonsson et al. 2003; Dionne
et al. 2008). Based on the previous studies and on
the fact that we do not have data on the behaviour of
noncaught salmon in those downstream pools, we then
suggest that C&R does not significantly impair the
access to reproduction of large salmon.
Within the group of large salmon for which at least
one offspring was assigned, C&R had a significant,
albeit weak, impact on the number of offspring inferred
and that effect was dependent on fish length. Thus,
while smaller fish fitness did not seem to be impaired
by C&R, larger C&R salmon produced significantly less
offspring than same size noncaught salmon. Previous
studies of the effect of size on salmonids post-release
mortality have led to mixed conclusions (Bartholomew
& Bohnsack 2005). However, size has been identified as
an important source of variability to the physiological
disturbance of rainbow trout captured by angling as
larger fish showed higher level of plasma cortisol, glucose
and lactate levels (Meka & McCormick 2005). In
Atlantic salmon, angled salmon showed decreased
plasma concentration of calcium and pH and a higher
plasma concentration of glucose, lactate, osmolarity,
chloride and sodium than nonangled fish and the magnitude
of the disequilibrium for plasma concentration
of calcium, lactate and pH was positively correlated
with body length (Thorstad et al. 2003). Larger fish take
longer to land and that could explain why they suffer
more important physiological disturbance and reduced
fitness from C&R (Thorstad et al. 2003; Meka 2004).
Fishermen should thus minimize the time elapsed
between hooking and landing to minimize the impact
of C&R.
Water temperature has been identified as a major predictor
of salmonid survival rate (Muoneke & Childress
1994; Thorstad et al. 2003; Boyd et al. 2010), explaining
72% of the variation in survival from Atlantic salmon
C&R angling (Dempson et al. 2002). Air exposure is also
associated with C&R-related physiological disturbance
(Ferguson & Tufts 1992; Schreer et al. 2005), and studies
recently showed that there are interactive effects of air
exposure duration and water temperature on survival
and physiological disturbances of C&R fish (Gingerich
et al. 2007; Gale et al. 2011). Here, water temperature
negatively impacted reproductive success of salmon
kept in the water, but in the temperature range of
12–17 °C, air exposure time had a greater negative
impact on fitness than water temperature. Depending
on the temperature, reproductive success can be up to
two or three times higher for salmon kept in the water
compared with those exposed to air for 10 s and with
those exposed to air for >10 s, respectively. Predictions
obtained for water temperature above 17 °C, where a
longer air exposure seems beneficial in terms of fitness,
as well as the positive relation between water temperature
and the number of produced offspring for the long
exposure time group, could be explained by the fact
that high water temperatures may enhance the recovery
of exercised Atlantic salmon (Wilkie et al. 1997). Thus,
the conditions in which C&R is conducted influence the
success of the practice in terms of conservation. Consequently,
precaution must be taken to limit C&R in
warm water periods and avoid air exposure prior to
release.
Overall, this study measured the impact of C&R on
individual reproductive success and allowed an evaluation
of its sustainability for an exploited fish population.
Nevertheless, our study suffers from limitations that
should be considered to improve further studies of this
type. First, ideally such studies should include more
than 1 year of data because other similar studies
showed that patterns of reproductive success and selection
gradients can change substantially from year to
year (Ford et al. 2008). Secondly, reproductive success
was evaluated at the fry stage only, and consequently,
comparison of the production of offspring that survive
to reproduce would be warranted in future studies.
Finally, there is a need to perform similar studies in
other populations to bring stronger support to our statements
about the general merits of this management
strategy.
 

·
Registered
Joined
·
104 Posts
fish out of water

http://forum.skagitmaster.com/index.php?topic=330.0

Here's the take away quote:

"According to Tufts, factors such as time out of water and length of fight combine to determine a released fish’s chance of survival. In his study, “Physiological Effect of Brief Air Exposure in Exhaustively Exercised Rainbow Trout: Implications for “Catch and Release” Fisheries”, Tufts studied the effect of time out of water periods of zero, 30 and 60 seconds for rainbow trout after exhaustive exercise. In 57-degree water, after 12 hours of recovery time, the control group-- fish that were held in captivity but not exercised--experienced no mortality. The group not exposed to air immediately after exercise experienced 12% mortality. The group exposed to air for 30 seconds after exercise experienced 38% mortality, and the group exposed to air for 60 seconds after exercise experience 72% mortality. 7 out of 10 trout died after 12 hours when exposed to air for 60 seconds."

Published this back in 2010. Bruce Tufts studies were not exclusively focused on Atlantic Salmon and I believe it is foolish to assume the steelhead are somehow unaffected by time out of water.

JM
 

·
Registered
Joined
·
116 Posts
http://forum.skagitmaster.com/index.php?topic=330.0

Here's the take away quote:

"According to Tufts, factors such as time out of water and length of fight combine to determine a released fish’s chance of survival. In his study, “Physiological Effect of Brief Air Exposure in Exhaustively Exercised Rainbow Trout: Implications for “Catch and Release” Fisheries”, Tufts studied the effect of time out of water periods of zero, 30 and 60 seconds for rainbow trout after exhaustive exercise. In 57-degree water, after 12 hours of recovery time, the control group-- fish that were held in captivity but not exercised--experienced no mortality. The group not exposed to air immediately after exercise experienced 12% mortality. The group exposed to air for 30 seconds after exercise experienced 38% mortality, and the group exposed to air for 60 seconds after exercise experience 72% mortality. 7 out of 10 trout died after 12 hours when exposed to air for 60 seconds."

Published this back in 2010. Bruce Tufts studies were not exclusively focused on Atlantic Salmon and I believe it is foolish to assume the steelhead are somehow unaffected by time out of water.

JM
It is foolish to apply Tufts study to Steelhead for the following reasons.

Sample size is tiny, with less then 8 fish in each category.
Individuals are in no way similar to steelhead size and lifestyle wise. They are resident rainbow trout of size between 300-500g. Not an anadromous steelhead that is 5kg or more (in other words the study fish are around 15% or less of a steelhead in weight).
Exhaustively Exercised is only 10 minutes of swimming due to being chased. Now if you are fighting a 500g fish for 10 minutes, you either are on too light of tackle or just suck at fighting fish.

The hilarious thing is people are applying this study to steelhead. Yet no where in the study is there anything remotely applicable except for maybe the exhaustively exercised part, but even then the min. air exposure is a lengthy 30 seconds....
 

·
Registered
Joined
·
305 Posts
I treat my wild catches like the gods they are.

I fish the upper Salmon (in Idaho). Except for early October, the water is cold (by a trout's standard). How many of you long-rodders see dead adult steelhead pre-spawn?

I don't think I've ever seen one and I've been living and fishing on this river for thirty years. Sure, I can't see into the deep pools, so I suppose it's a bit anecdotal.
 

·
Registered
Joined
·
2,735 Posts
Discussion Starter #14 (Edited)
clarkii

the original link had nothing to do with the Tufts study but one that was related to atlantic salmon

but I will pose this - If I had held your head under water as a baby for a minute or held your head under water now for a minute - I expect your stress level might be the same!!!:razz:
 

·
Registered
Joined
·
357 Posts
If ur bye ur self don't take pictures most anglers don't have enough skill and experience to land fish quick enough for photo and they usually look poor smaller with self shots when u have fishing buddy if he or she willing to come over have camera ready and is familiar with camera take 2 second shot that's it I like water shots also in magazines the majority of fish have a dead eye fish should have down turned eye every time not deer in headlights look
 

·
Registered
Joined
·
116 Posts
clarkii

the original link had nothing to do with the Tufts study but one that was related to atlantic salmon

but I will pose this - If I had held your head under water as a baby for a minute or held your head under water now for a minute - I expect your stress level might be the same!!!:razz:
Rick for starters my reply was to the post that referred to Tufts study of the effects of air exposure of exhaustively exercised resident Oncorhynchus mykiss in context of the anadromous form and not Salmo salar. Second in response to your question, I will instead ask more to start. What makes you believe that as a human my tolerance for low available oxygen environments is the same as a fish? Second why did you neglect to add exhaustive exercise to your question?

Therefore to answer a relevant question I will modify it. As a child (say 8) my stamina was much lower, so exhaustive exercise occurred quicker than it does now that I am a young Adult (20). So now I have been exhaustively exercised, I will stick my head underwater for a set length of time. Now I have not tested this (and nor has Tufts) I cannot comment on the stress I as an individual can keep my head underwater compared to my younger self. What I can do however is note my recovery time as a 20 year old is greater than when I was 8. Now again I do not know if a significant difference occurs or not. Another variation I will acknowledge is me as a 20 year old against a 20 year old who games on the computer and doesn’t exercise, and a 20 year old Olympic swimmer. Here I am acknowledging the potential for the resident O. mykiss to be the same age class as the anadromous O. mykiss. In this scenario, I would expect exhaustive exercise to occur faster in the 20 year old on the computer, and the swimmer to exercise the longest. Now stick our heads underwater. Who will last the most stress?

My point in this is we need to understand the scope of these papers. There is an ideology that contradicts good science by assuming because of a major similarity with one of the control variables (species in this case), the study immediately has ground despite the fact other specific control variables exist. The controlled variables in this study are species, lifestyle, state of exhaustion, individual size, water temperature, salinity etc... The test variable is amount of air exposure. Using this study as a “fact” or “representative” in application outside any of the control variables is not only an assumption, but invalid.
 

·
Registered
Joined
·
2,735 Posts
Discussion Starter #17
clarkia
You raise good points but I wonder which fish is more stressed - an "adult" trout played for say 1 to 2 minutes or a steelhead played for say 5 minutes. Likely a steelhead has more stamina but it takes longer to play a big fish.

The atlantic salmon study would indicate that larger fish were more stressed and perhaps less likely to produce and or survive than smaller fish.

In any event, to say that there is no comparison on the effects from air exposure for studies that look at trout vs. steelhead vs. atlantic salmon seems a bit extreme. Whether or not the studies can be directly compared, I think anyone with common sense would agree that air exposure for fish isn't a good thing - how much air exposure before there is an impact is unknown and it seems is still up for debate but it appears that even if impacts are not lethal there can be other significant impacts not readily understood or considered by many

Best,
Rick
 

·
Spey Hack
Joined
·
153 Posts
Im going to go out on a limb here and not refer to any studies.

If you are releasing a wild fish you should do everything in your power to release it as it was found. If it really is the steelhead of a lifetime and a grip and grin is what you want then hell go for it but yet again do everything in your power to minimize air exposure such as keeping it in a net until you pick it up, have camera man absolutely ready, and keep the camera on burst mode. Realisitcally it could be executed in less than 3 seconds and assure atleast 15 photos on most DSLR's with a wide variety of shots from in the water, to grip and grin, to the awesome realease shot.

All anglers are going to approach the idea of not exposing fish to air differently and I think its safe to say stress is an addicitve property. The point being made is to minimize stress at all extremes all accross the board and this is coming from a great lakes steelheader where my fish aren't nearly as precious. If you are a grip and grin supporter and dont own a quality net you are obviously doing more damage than you should be in my opinion not to mention the time saved in battling a fish and the ease of netting it in deeper water vs tailing in shallower water. Barbless hooks being another way to minimize issues aswel as avoiding lighter rods and lines than necessary. On the east coast the way some of the fish get handled you are only lying to yourself if you claim to be a catch and release fisherman because in reality you are just letting a good meal go to waste when it ultimately gets consumed by birds.
 
1 - 18 of 18 Posts
Top