Brook trout (ST) C&R: no added benefit to ST size or abundance

[Mike]

Brook Trout Fishing Study Summary

Great Smoky Mountains National Park

Study Purpose: The purpose of the three-year experimental brook trout fishery was to determine if legal fishing and harvest would impose any detrimental population level impacts to brook trout populations. The results of this study will be combined with results from angler creel surveys collected during the study, law enforcement staff observations, and data from outside Great Smoky Mountains National Park in order to make a decision regarding fishing and harvest of brook trout Park wide for present and future generations.

Study Design: Eight streams (4 in TN, 4 in NC) were opened to fishing and harvest for 3 years under the current GRSM fishing regulations (i.e. 5 fish creel limit, 7-inch size limit, and single hook artificial lures only). Each stream that was open had a control stream which remained closed. Some streams were easily accessible and some were accessible by 5-7 mile hikes. We analyzed population abundance data from 2-3 sites within each stream (both open and closed) for three years prior to and three years after brook trout fishing was opened. An angler creel survey was also conducted during the study period in order to compare angler catch and harvest data to biological data. The following are the results of the study:

Objective #1: Has adult brook trout density (# fish/100m2) declined >30% over a 3-year period due to fishing (pre-fishing vs. post-fishing)?

Results: There were no significant differences (declines) in adult brook trout density in seven of eight streams opened to brook trout fishing during the study period (Figure 1a & 1b). A significant increase was observed in adult biomass in Hazel Creek (p=0.025). Variation which did occur was attributed to natural variation and was not related to open vs. closed and/or easy vs. difficult access.

Objective #2: Has young-of-year (YOY) or age-0 brook trout density declined >50% over a 3-year period due to fishing (pre-fishing vs. post-fishing)?

Results: There were no significant differences (declines) in YOY brook trout density or biomass in any stream opened to brook trout fishing during the study period (Figure 2a & 2b). Variation which did occur was attributed to natural variation and was not related to open vs. closed and/or easy vs. difficult access.

Objective #3: Has the number of legal brook trout (>7-inches) declined over a 3-year period due to fishing (pre-fishing vs. post-fishing)?

Results: There were no significant differences in the number of legal brook trout brook trout in any stream opened to brook trout fishing during the study period. In all cases, significant differences that were observed were increases (green) or in control stream. Variation which did occur was attributed to natural variation and was not related to open vs. closed and/or easy vs. difficult access.

Angler Creel Survey: There were 271 anglers interviewed during the three-year study period of which 95% (257) were male and 5% (14) female (Table 1). Of those anglers, 44% (120) were local and 56% (151) were non-local (those living >50 miles from the Park boundary). Local anglers have been fishing and average of 19.8 (range 0-72) years and 63% of these anglers fish >20 days per year in the Park. Non-local anglers had fished an average of 5.8 (range 0-39) years however, 63% of these anglers only fish 1-5 days per year in the Park. Angler satisfaction was very high with 84% of locals and 88% of non-local anglers characterizing their experience as moderately enjoyable to excellent. Both local (27%) and non-local (25%) anglers cited “to catch a brook trout” as the number one reason they fished that particular stream when interviewed. Both local (50%) and non-local (46%) anglers cited acid rain as the number one future threat to GRSM wild trout populations. Between 77-80% of all anglers did not belong to a fishing club of any kind. Despite fairly high catch rates for local (3.5/hr) and non-local anglers (1.5/hr), harvest rates were extremely low (0.3 and 0.1 fish/hr). Only 32% of local and 26% of non-local anglers indicated they would harvest a legal brook trout if they caught one. Study results verify these results indicating that only 33% of local and 17% of non-local anglers who caught legal size brook trout actually harvested the fish. Most local anglers spent around $30.66 per trip (range $0-$350) whereas non-local anglers averaged $187.97 per trip (range $0-$1,500).

Summary: Given these biological and angler creel results, it is apparent that legal angling had no detrimental population level effects on brook trout populations in Great Smoky Mountains National Park. Both un-fished control streams and fished streams exhibited the same variability among years and no streams had significant differences between the fished and un-fished period. Angler creel results verified the biological results found during the study period (Table 1). Despite high catch rates (1.5-3.5 fish/hr), angler harvest rates were extremely low (177mm than streams where harvest was allowed. Furthermore, Borowa et al. (1995) found that harvest rates of trout (>177mm) in streams open to single-hook artificial lures was 177mm) or length frequencies between bait fishing, single-hook artificial, and closed streams. A recent wild brook trout creel study conducted by the Virginia Department of Game and Inland Fisheries (VDGIF) utilizing similar size limits (7 or 9-inch) found that no brook trout were harvested during the study despite the fact that many anglers caught legal sized fish (Steve Reeser, VDGIF personal communication). Stream access varied from easy to difficult, regulations varied from bait fishing to artificial single hook regulations, and streams received a variety of fishing pressure. When asked about harvesting wild brook trout, 87% (181) of the anglers interviewed (N=208) indicated they had no desire to harvest brook trout, just to fish for them.

References
Borowa, J.C., C.J. Goudreau, and M.M. Clemmons. 1995. Responses of wild trout populations to supplemental feeding. North Carolina Wildlife Resources Commission, Division of Boating and Inland Fisheries, Raleigh.

Borowa, J.C and M.M. Clemmons. 1998. Evaluation of a wild trout regulation with a natural bait allowance. North Carolina Wildlife Resources Commission, Division of Inland Fisheries, Raleigh.

Borowa, J.C., J.H. Mickey, Jr., C.J. Goudreau, and M.M. Clemmons. 2001. Wild trout population monitoring summary, 1989-1996. Final Report, Mountain Fisheries Investigations. Federal Aid in Fish Restoration Project F-24. Raleigh, North Carolina.

 

[Wmass]

I am still highly suspicious of these results. 5 fish at a 7in min. limit is alot for a species that thrives in areas/streams that tend to be low in food sources. I would guess that the stream in this study didn't have enough fishing pressure to make the population decline, they should instead try a stream with easy access and alot of pressure and see how the population is effected.

 

[Maurice]

Well Mike, the way I see it, with harvest calculated at only 10-15% on the harvest streams compared to non-harvest streams means that only harvest can be characterized as insignificant.

In this study, harvest is not significant factor on the populations because, harvest was not significant.

For example, if in the areas sampled (100m2) there were 10 ST over the legal limit, only 1-2 would be removed with harvest. That is not even a limit. Take two limits and they are gone.

Keep in mind that these streams are in a National Park and the creel survey opportunity is a "captured audience sample" with ample manpower to conduct the surveys. As opposed to the manpower haveintg to travel to many, many different rural areas and state forests to do same.

I appreciate your sharing this with us but I would be more convinced that harvest has no impact if the harvest rates were higher AND the abundance stayed the same or had no significant difference.

It's like I have een saying, if you don't put the fish in a skillet, they will be there for you to catch.

No sale!

It is interesting you bring this up with tomato season right around the corner..... :lol:

Maurice

 

[SlumpBuster]

In many streams harvest has no affect on the population. Yes of course a stream where 90% of the legal sized fish were harvested would have a steep decline in numbers. But this is no usually the case in streams with wild fish. Only streams with stocked fish should have harvest rates like this and do. On some streams harvest will actually inprove the fishing and may streams need some harvest. This one study is definitly not enough for you to change your mind I am sure, read more professional articles and you will easily see the benifits to harvest on some streams, and you will also see how it can ruin some.

 

[OhioOutdoorsman]

Well, I think this is a good real world study. "Bluelining" in GSMNP is very popular, more popular than I think it is in PA. I travel down there 1-2 times a year to do it myself. I'm quite sure the pressure is lighter there. If you look at freestone streams, like the ones represented in this study, it takes nearly 4 years for a fish to reach 7 inches.....this is a very low % (

 

[troutbert]

Sooooo. Catch-and-release regulations are unnecesary, if anglers fish catch-and-release.

I could have told you that.

 

[troutbert]

On some streams harvest will actually inprove the fishing and may streams need some harvest. This one study is definitly not enough for you to change your mind I am sure, read more professional articles and you will easily see the benifits to harvest on some streams, and you will also see how it can ruin some.

Do you have any references to studies that show the benefits of harvest on some streams?

 

[Mike]

The study certainly supports what I have said in the past. Special regs or more conservative regs or increased protection (however you want to say it) will have no effect when angling mortality (harvest and C&R mortality combined) is low. It does not matter why it is low, just that it is below some threshold level (a threshold that is probably higher than was found in this study). What's more, according to the authors' review of the references in the paper above, low harvest of wild brook trout from freestoners is being found in other cases, supporting what has been found in Pa. (wild trout creel survey).

Most importantly, C&R or other special regs don't need to be mandated as a general rule; they are only necessary in UNUSUAL cases for brook and brown trout where angling mortality rather than natural mortality is largely driving the population size distribution and abundance (and where there is substantive concern about that size distribution and abundance). Low enough harvest is occurring in the vast majority of unstocked Pa wild trout streams without a mandate for a harvest reduction; otherwise, the results of the statewide wild trout creel survey would have been different.

 

[Mike]

Troutbert said:Sooooo. Catch-and-release regulations are unnecesary, if anglers fish catch-and-release.

I could have told you that.

Mike responded: I have to keep you honest. The paper clearly indicates that there was voluntary C&R fishing as well as harvest taking place.

 

[Mike]

Maurice, I think if you look at the number of legal trout per mile recorded from a 74 stream subsample in the wild trout creel survey vs the number of trout per mile harvested in the creel survey you might find even lower harvest rates on average in Pa than were recorded in the national park. Just a hunch.

 

[afishinado]

C’mon fellas! There may be a small number of wild trout streams that are impacted by harvest, but the real problems to fight are development of the watershed and the storm runoff, sewage, and the loss of riparian cover associated with that, as well as agricultural runoff, AMD, and acid rain. Solve those problems and the PFBC will have to raise the limit and encourage fisherman to keep fish because the streams are exceeding their carrying capacity.

Having said that Mike, I am in favor of more special regulation waters, especially in the SE region, given the overcrowding of the limited number of SR waters right now. Unfortunately quality wild trout waters with access are not in abundance in the region.
More SR waters would give trout fishermen an opportunity to catch fish for more than the month of April and a few weeks in May on stocked waters, and spread out the fishing pressure.

 

[SlumpBuster]

@Troutbert

I can definitely find some papers. I need so time to look for them though.

@afishinado
Special Regulations on stocked streams are totally unnessicary and stupid. Stocked trout are there soley for the purpose of harvest. Even if not harvested it is most likely that over 95% of the stocked fish will die. Why put SR on the stream if the fish will die any ways. Let them be harvested and allow people to get thier money's worth for thier liscenses.

 

[nimrod]

Quote:

C’mon fellas! There may be a small number of wild trout streams that are impacted by harvest, but the real problems to fight are development of the watershed and the storm runoff, sewage, and the loss of riparian cover associated with that, as well as agricultural runoff, AMD, and acid rain.


This hits the nail on the head IMO. Fishing in New England back in my yute, there were no special regulation rivers. As an example, creel limits on rivers like the Battenkill in Vermont were 12 fish per day and it was largely unstocked. On opening weekend, and maybe the next couple, you'd get a bunch of bait fishermen, myself included, most of whom didn't do very well. The river was usually swollen and turbid with runoff. After the first few weeks of the season fishing pressure would taper off considerably and, as the water cleared and lowered the bait fisherman tended to disappear and be replaced by lesser numbers of fly fisherman, many of whom practiced some form of C&R but certainly harvested some fish. Long story short (too late) fishing pressure tapered of early and the river easily replaced the harvested fish. I could often see dozens of trout fry hiding among the bushes on the rvier's edge.

Now my understanding is that all of those factors that afishinado noted have taken their toll on the Battenkill, not previous harvests. Those problems are long term and potentially devastating. Keeping a few fish isn't.

 

[afishinado]

Slumpbuster wrote:
”Special Regulations on stocked streams are totally unnessicary and stupid. Stocked trout are there soley for the purpose of harvest. Even if not harvested it is most likely that over 95% of the stocked fish will die. Why put SR on the stream if the fish will die any ways. Let them be harvested and allow people to get thier money's worth for thier liscenses.”


Slumpbuster,

I disagree, there are many SR areas that can hold stocked trout at least 9 months a year, and some 12 months like the tail water fisheries – Tully, Yough, Lehigh, Pohopoco, etc. In addition, the Little J has very few wild trout and relies mostly on stocked fish. If there were no SR areas and every mile of stream in the State was open to general harvest, the trout season would last less than two months (April and May) a year. In the DH waters, fall stocking extends the fishing through the fall and winter. I agree that SR areas are put into place for “social” reasons, but they serve a purpose in regions and waterways not blessed with the capacity to hold wild fish. Further, without the SR areas attracting trout anglers, wild trout streams would see more pressure from anglers and license sales would decline, giving the PFBC less resources for all programs.

I take issue with the attitude shared by many anglers in this State that all stocked trout are commodity to be yanked out of the water and fried up in the pan. There are many miles of marginal waters that trout should be caught and kept, but in waters suitable for holding trout, catch and release makes sense to keep the stream vaible for fishing. The PFBC should continue to identify waters where the survivability of trout is feasible, and C&R regulations would make the fishery viable for more than six weeks.

Mike, what do studies say about the survivability of stocked trout in certain PA streams?

I just read your profile and you are from Mansfield (a student?) and have another year to graduate as a fisheries biologist, and plan to live in Bozeman, MT. Montana is blessed with an unbelievable amount of wild trout fisheries (no stocking in the entire State). Montana is the Mecca of wild trout fishing and I couldn’t think of a better place to be a fisheries biologist. Good luck with that.

 

[SlumpBuster]

afishinado,

yes there are certian streams that will have holdovers. but many studies (for instance Bob Bachman's) have shown that fish stocked in streams where trout can be supported year round even have a hard time surviving. These "holdovers' you catch may actually be wild trout. If they can survive it for 9 months then i am sure they can survive year round. Check out the list of streams that support natural reproduction in the state. You may be suprised to find the ones that do. I am from SE PA and grew up next to a stocked stream. During the summer the stream gets very warm much warm than i thought would be able to keep trout year round. Recentely though i have seen more and more wild trout fry and fingerlings. Not having fished it in several years though i am not sure how many actuallly survive.

Bozeman is where I plan to attend grad school. Yet i do also hope to live and work in the state as well.

 

[OhioOutdoorsman]

I take issue with the attitude shared by many anglers in this State that all stocked trout are commodity to be yanked out of the water and fried up in the pan. There are many miles of marginal waters that trout should be caught and kept, but in waters suitable for holding trout, catch and release makes sense to keep the stream vaible for fishing. The PFBC should continue to identify waters where the survivability of trout is feasible, and C&R regulations would make the fishery viable for more than six weeks.

Well, I'd say the PFBC is obligated to provide fishing experiences in proportion to the # of fisheman who want those experiences. Some fisherman (like my dad and other occaional, casual fisherman) get 90% of their enjoyment out of eating fish while C and R fisheman get 90%+ of their enjoyment from catching the fish again. We get the DHALO, FFO, trophy trout, and other special regs areas to support us to varried degrees.

 

[JackM]

SlumpBuster wrote:
....many studies (for instance Bob Bachman's) have shown that fish stocked in streams where trout can be supported year round even have a hard time surviving. ....

Having been interested in claims such as these over the years, I have requested numerous times info on these "many studies" yet the only one I have ever been sited to is the Bachman study, which has always concerned me in terms of the data being based solely on visual observations. My experience tells me otherwise, and that is that where stream chemistry, temperature and forage are sufficient, adult-stocked, hatchery raised trout can and do last well into the regular season and can be caught 2-3 times and still survive.

 

[troutbert]

Mike wrote:
Troutbert said:Sooooo. Catch-and-release regulations are unnecesary, if anglers fish catch-and-release.

I could have told you that.

Mike responded: I have to keep you honest. The paper clearly indicates that there was voluntary C&R fishing as well as harvest taking place.

I understand that voluntary C&R fishing is taking place. The paper is saying high harvest regulations "work." And the reason they work is that most people practice C&R.

It's limited harvest that's maintaining the population. And most anglers prefer limited harvest. To say that these points support the choice of HIGH harvest regulations just simply doesn't make sense.

It does just the opposite. It supports the idea of LIMITED harvest regulations.

The conservation-oriented anglers have led the way, and are helping maintain the population by voluntarily sacrificing their evening meal, because they think maintaining brookie populations is important. Instead of following the lead of these foward thinkers, the managers are essentially slapping them in the face by saying, you guys are releasing fish to maintain the population, well guess what, we're going to allow high harvest on these streams, so the guys who don't care a fig about conservation can harvest and eat the trout that you guys voluntarily released.

So the managers aren't supporting the voluntary efforts of the conservationists, they are supporting the activities of the high harvest crowd.

 

[afishinado]

Slumpbuster,

Ironically, Dr. Bachman’s study was done primarily on Spruce Creek. Wild trout on Spruce Creek are now few and far between. They have been displaced by stocked trout! I believe that the PFBC has taken Spruce off the list of streams containing a significant amount of wild trout. I know, I fished a private stretch (not SRC water!) not long ago. Of all the fish I caught, only a small handful were wild. Greed by certain people has caused this with the stocking one of the premier wild streams for their own purposes (to make money). What a shame.

The fact is SR areas have their place for both wild and stocked trout in PA. The most important point I tried to get across is that harvest regulations are the last and least effective means of improving and protecting our fisheries – preservation of the habitat should be our prime concern.

 

[RLeeP]

Here's something I wonder about...

Are they any studies with good methodology and good control or even educated estimates that attempt to measure what percentage of a wild trout population in a small stream environment is actually susceptible to angling pressure or presentation by a given angler, let's say a highly skilled angler.


In a 300 meter mark/recapture survey, let's say 15 brook trout >177mm are recorded. What percentage of these fish is the next "skilled" angler to fish up through that section of water likely to be able to "move" or entice to consider taking a fly/lure/bait? How about the next 15 guys that fish through?

I don't know if such a thing is measurable, but I would suspect some indication could be had by simply contrasting abundance surveys with angler interviews.

I think the answer to this would tell us a great deal about the actual effects of pressure on a healthy wild brook trout population

My suspicion is that a fishing rod is a pretty poor and inefficient sampling tool. But I've seen and heard a lot of ancedotal evidence that seems to point both ways of the effects of harvest.

One thing seems certain to me: The more the dispositional profile of the trout fishing public changes from a harvest orientation to a C&R orientation, the more of a redundancy C&R regs seem in some ways.