Fish Explorer Logo
Colorado Fishing
Colorado Fishing
Login Usr:Psd:
Don't have an account? Register now...

spacer spacer

Fishing Regulations: Backed by Survey Data

by: Ben Swigle 5/1/2013

A recent report delivered by the American Sportfishing Association highlighted the broad economic impact the angling community has our nation’s economy. This report delivered some astonishing findings, concluding that there are approximately 60 million anglers in the U.S. with more Americans fishing than playing golf (21 million) and tennis (13 million) combined. Furthermore, if fishing were a company, sales would rank number 51 on the Fortune 500 list, generating more revenue than blue chippers such as Lockheed Martin, Intel, Chrysler or Google. Here in Colorado, fishing ranks as the second most popular recreational activity behind skiing. With angling participation in Colorado remaining fairly steady since 2005, improving Colorado’s ponds, reservoirs, streams and rivers for the angling public is a difficult endeavor in light of challenges including water development, increased angling pressure and aging hatchery facilities. Fortunately, the state’s fish managers have a variety of tools available to gauge the health of fish populations and provide users with the best possible experience.

Equipment routinely used by fish managers includes a variety of nets and electrofishing. Netting fish is fairly self-explanatory but electrofishing is survey method by which an electric current is applied to the water causing fish to involuntarily swim toward a crew member carrying the electrode and a dip net. When performed correctly, electrofishing results in no permanent harm to fish or the sampling crew. The basis for the surveys lies in the ability to accurately catch, measure and safely return as many individuals as possible. In turn, analysis of the data determines parameters such as abundance, density and species composition. Additional information is also collected by directly interviewing anglers (creel survey); however this often overestimates catch rates, especially total fish length…..that’s a poke and a prod there!

Armed with a pile of unbiased scientific data, the fishery manager employs 1 of 3 basic principles. Often the easiest option, fish production and stocking, is used to increase abundance by requesting a specific species (predator or prey), size and amount from one of the state’s 18 hatcheries. The second option is aquatic habitat improvement which seeks to bolster natural production and increase the number of fish that can inhabit a given area. Most folks envision trout-stream restoration as the prime example of habitat modification. This option spans the spectrum from an Eagle Scout’s community Christmas tree project to negotiating river flows with entities such as Denver Water. The final tool available relies almost exclusively on the angler, that being fishing regulations. Whether the goal of a particular regulation is to project breeding adult fish or simply spreading the wealth of the natural resource among as many anglers as possible (see possession limits), fishing regulations appeal to the broad idea of managing individual waters for angler by anglers. While the fishery survey is the scientific backbone for fishing regulations, the angler largely influences personal compliance and, accordingly, the ultimate success of fisheries management in Colorado. Here is a brief look at some regulatory examples along with the reasoning behind them.

Big Thompson River (Watonia Bridge to Olympus Dam) – Artificial flies and lures, trout must be returned to the water immediately.

Despite the fact that there are actually more trout per mile below the catch and release section a 1990’s creel survey on the Big Thompson revealed that the upper section received the lion’s share, or more than 2 times the amount of fishing pressure. Given the fact the upper section fish were twice as likely to be caught this regulation was implemented in the 90’s

Poudre River (City limits – Fort Collins) – general fishing regulations, 4 trout any method.

Recently the argument was suggested that trout fishing with the city limits of Fort Collins should be more restrictive. Based on data collected by interviewing hundreds of anglers over a 3 month period it was determined less than 3% of trout caught were actually harvested thus a special regulation was not warranted as the section, for the most part, falls under a de facto catch and release regime.

Carter Lake – Bag and maximum size for walleye is 3, 21 inches long.

During the mid-90’s walleye in Carter were relatively sparse and smaller; following a regulation change in 2003 which reduced angler harvest, the population rebounded and expanded to a point the reservoir could not sustain. For example, annual fall gillnet surveys completed 1990-2002 yielded an average annual catch rate 0.26 walleye per net hour; between 2003-2009 the average annual catch rate tripled to 0.76 walleye per hour net hour. In addition to population expansion, the size structure of Carter’s walleye shifted to a point where much of the population now exceeds 20 inches in length. In short, more walleye are now present in Carter following the 2003 regulation change and the fish are much larger. Average annual walleye condition prior to 2003 averaged 119, since the regulation change average annual condition of walleye measures 100 and has decreased each year since 2003. The dietary requirement of Carter’s walleye cannot be sustained through natural forage production; thus angler harvest was increased from 1 fish to 3. This regulation allows angler to catch and photograph a trophy walleye, provide a back-up location to take eggs, thin the herd to which expedites growth of remaining walleye while reducing the direct predation of walleye on hatchery reared trout.

Virtually all fishing regulations are rooted in biology or the need to accomodate the greatest number of anglers. I'll check back in here and there, and try to answer some specific questions but the field season is heating up. I posted some photos of a variety of equipment employed.

Hopefully, by now, most of you have noticed we post the results of our surveys for the higher prioirty waters.  That infomation is available here:

Go Fish Colorado!

Back-pack shockerselectrofishing boatStream electrofishing
trapnetsGillnetsYear class strength - white bass at Boyd
Blog content © Ben Swigle
Member comments
tracks, CO   5/1/2013 4:06:49 PM
Nice information Ben! I alway read the fishing surveys (sometimes more than a few times) when they are updated. I truely appreciate the work that you and the other biologists do for us with these surveys!
boogieman, CO   5/1/2013 4:26:02 PM
Mr. Swigle, Interesting article and I appreciate learning about the approach of tailoring management regulations based on data collected. However I had a question out of the 3% of fish caught within the Poudre that were harvested. What size were the fish kept compared to the fish released? And was other information about the anglers fishing methods collected as well? I routinely fish the Poudre and the fish I see on fellow fisherman’s stringers generally are on the larger side. I rarely see people keeping the smaller fish and I was wondering if my observations aligned with the three month survey conducted? If you don’t have time to answer any or all of my questions I completely understand, but I figured it couldn’t hurt to ask. Thanks!
Fishful Thinker, CO   5/1/2013 4:28:14 PM
It's been very humbling to sample with CPW crews...there's always way more and way bigger fish than I think based on my catching. Thanks Ben...excellent info! CL
CNR Walleye, CO   5/1/2013 4:55:46 PM
Ben on the next 5 year regulation plan are you thinking of changing the Carter lake regulations again or are you planing on keeping the 3 fish limit? Also on Carter why do they still allow snagging for kokes when the koke population is so far down? Thanks
Ben Swigle (Swigs), CO   5/1/2013 5:21:58 PM
There was nothing special about the kept fish from the lower Poudre and the number of adult trout per mile was similar to C&R sections upstream.....average about 10 inches.
Ben Swigle (Swigs), CO   5/1/2013 5:24:12 PM
The Carter regulation was chaged Jan. 1, 2011. I do not anticiapte changing it again in 3 years. The snagging has not come off the books in the hope that someday we could start kokanee again if the walleye number become a more balanced or if extra kokanee were available (not the case this year).
aerofanbig, CO   5/1/2013 7:39:43 PM
Ben we have conversed several times over email and you've been extremely willing to lend tips and be helpful. I'd love to repay the favor sometime helping out with a survey! I'm really glad you are a part of the FxR community now. So many people have a negative view of what you do based on their own selfish desires and don't ever see the whole picture. Its refreshing to have posts like this here
Ben Swigle (Swigs), CO   5/1/2013 7:59:42 PM
aerofan....send me an email. I lose my FRCC interns soon and won't get seasonal help until June 1. Its best if you are in the vacinity of Loveland/Fort Collins/Longmont.
aerofanbig, CO   5/1/2013 8:10:34 PM
I can help on the Southern end of that city list lol. I'll get an email off to you
alanlf5280, CO   5/1/2013 9:16:37 PM
Swigs, do you or Paul look for volunteers often for surveys or is it more of a if you are interested, we will try to make room?
JKaboom, CO   5/2/2013 7:16:40 AM
Thanks for the insight :)
Ben Swigle (Swigs), CO   5/2/2013 9:11:48 AM
Alan5280, Paul and I generally need help with the big river surveys in the fall which comes out in the quartly volunteer mailer. We also have volunteers associated with walleye spawn at Cherry Creek and Chatfield March 17-April 3, roughly.
pikeNcolorado, CO   5/2/2013 5:31:16 PM
Ben, You know I'm down for more, just email me and I'll be ready. Devin (aka pikeNcolorado)
alanlf5280, CO   5/3/2013 8:28:25 AM
Thanks for the info! How do we get our name on the list? I will shoot Paul an email. There is a specific project taking place in the Denver area I would like to see how it's done, even if only from shore.
boogieman, CO   5/3/2013 8:40:50 AM
Hmm. Well thanks allot Mr. Swigle. We all appreciate the work you do!
Ben Swigle (Swigs), CO   5/3/2013 9:37:53 AM
boogieman. Go to the survey summary page via the link and click on Cache la Poudre, tons of information there.
Ben Swigle
View bio