Pond Boss Forums INTRO Questions & Observations FYI - Coming to PB mag in May!

Go order Pond Boss Magazine – now !!!!!

This post has 1 goal – to get you to think about subscribing to Pond Boss, if you don't already.

It has 2 firsts!

One, a request that you support the Forum by subscribing to Pond Boss Magazine. Click here: http://www.pondboss.com/subscribe

Second I am jumping the gun on a topic that is upcoming soon in PB Mag in May by giving you a peak at the topic. I guarantee it is a topic that will interest you about your fishery. I've reviewed the literature, and summarized some interesting information

Take a look and let’s see what you think. FYI it is equally about most fish species, not just LMB which were the test species. There is a lot here and a lot more to consider.


Can Largemouth Bass Transplanted from an Unexploited
Population Genetically Contribute to an Active Fishery? A Test
Case for Genetic Management of Exploited Fish Populations
North American Journal of Fisheries Management 37:271–283, 2017
© American Fisheries Society 2017 - Jan-Michael Hessenauer, Jason Vokoun, Amy Welsh, Justin Davis, Robert Jacobs & Eileen O’ Donnell

Recreational fishing is one of the most popular outdoor activities in the world, resulting in substantial effects on
recreational fish stocks. Recent studies have found that recreational angling may drive fisheries-induced evolution,
resulting in changes in the size, behavior, and physiology of exploited recreational stocks.

Recent studies have attributed differences in size, behavior, and physiology of fish species to the evolutionary impacts of recreational angling (Uusi-Heikkilä et al. 2008; Matsumura et al. 2011; Alós et al. 2014a, 2014b; Hessenauer et al. 2015). For example, a modeling study found that recreational fishing may deplete high-activity phenotypes because highly active fish are more likely to be encountered and captured by recreational anglers (Alós et al. 2012).

Philipp et al. (2009) demonstrated that vulnerability to recreational angling is a heritable trait (heritability h2 = 0.15) by conducting multigeneration artificial selection on Largemouth Bass based on the number of times individuals were captured by experimental angling. Further studies on the lines developed by Philipp et al. (2009) revealed that selection from recreational angling acts on a suite of behavioral (Cooke et al. 2007; Nannini et al. 2011; Sutter et al. 2012), physiological (Cooke et al. 2007; Redpath et al. 2010), and reproductive (Cooke et al. 2007; Sutter et al. 2012) traits. Individuals that were bred for high angling vulnerability had higher metabolic rates (Redpath et al. 2010) and higher reproductive success (Sutter et al. 2012).

We explored the potential to genetically manage exploited fisheries by introducing individuals from unexploited populations as a means to mitigate selection from recreational angling.

Decreases in population-wide vulnerability to angling represent a challenge faced by recreational fishery managers who seek to maintain high angler catch rates and attendant angler satisfaction, among other objectives. Because selection reduces angling vulnerability but does not necessarily reduce fish density, declines in traditional indices such as angling CPUE may not reliably predict changes in population abundance (Askey et al. 2006; Klefoth et al. 2013). Selection from
angling is also correlated with fish energetics (Redpath et al. 2010; Hessenauer et al. 2015); therefore, selection for reduced vulnerability may have ecosystem-level consequences.


Second study

Loss of Naivety to Angling at Different Rates in Fished and
Unfished Populations of Largemouth Bass
Transactions of the American Fisheries Society 145:1068–1076, 2016© American Fisheries Society 2016 , Jan-Michael Hessenauer*1 and Jason Vokoun Justin Davis, Robert Jacobs, and Eileen O’Donnell


Read about these studies in the May-June issue of Pond Boss.

Decided to short hand the above to make it more understandable. This line of studies has profound impacts on pond mgt for several reasons.

Recent info reveals that genetic change in fish can be very rapid. When I first saw this trend in writing a couple years ago I thought it was crazy. Then more and more examples were reported. Couple that with additional info that people can accelerate this process and you quickly have pond problems on your hand. These rapid changes have been shown to effect reproduction , catchability , aggressiveness , size (metabolic rate) and fitness/condition. See the chart below for an example over just a few years.

Here is 1 on catchability - the chart below shows a 50% reduction in catch rates over 3 generations.

I had seen you posted this awhile back, and was surprised the techie pondbossers have made no comments on it. Hibernation perhaps? I am not one for too much info overload techy details.

Ok, so I will bite.

So if I am understanding this correctly, it supports the notion that electroshocking and seining/netting are the best way to improve the situation of uncatchabilty? Also, how about when you remove the fish (not use the catch and release practice). Is this saying the other fish(not caught)see and learn this, then can pass it on. Where I am going with this is, even if you add new stock to the pond they will learn from their predecessors to not bite?

The study indicates that harvesting bass by hook and line only culls the most aggressive fish from the system. If we continually harvest by angling, we leave behind the hook-shy fish. When the fishery gets to a certain point, all we have left are hook-shy bass, and when they breed, the study suggests that trait is carried on in the offspring. Since the study suggests this is an inherited trait, new stock can't 'learn' from existing stock.

So the addition of highly aggressive genes to an existing stock of non aggressive fish should help revitalize the population - you can speed things up two fold by removing those non aggressive fish as well

There are a lot of different possibilities , ramifications and unknowns . We will examine some in the article.

That was a very interesting article and concept. I also enjoyed the article by Dr. Boyd on secchi disk use. I hope every pondmeister realizes that one of his best investments toward reaching his pond's goals is a subscription to the PB magazine.

That may explain why I haven't seen some of my bass in like FOREVER!!!! lol

RC

Ok so if new stock cant inherit from existing stock great I got that. But how do you know new stock does not have this hook shy trait? And if this is true then wouldn't everyone want the non hook shy fish all the time?

I guess what I am asking is. How does one know if you have the non hook shy fish, v.s. the hook shy fish??? If I pickup 50 lmb from a fish hatchery do I ask for non hook shy bass? they may think I am nuts!!! LOL..

RC

There are many possible approaches to this matter. Some were discussed in a PB mag article a few years back - about what you can do in ponds to reduce the catchability problem.

All LMB have the potential to have reduced catchability. Some more than others. These studies were about "Genetic Rescue" and measuring catchability. Some hatcheries have for years segregated out aggressive LMB to be used for broodstock. They are often northern LMB that are to be used with Fla LMB to create F-1s. They are called Tiger , Tigre , or other names. So the concept is not new to hatcheries. How do they do that ? By using the same methods as the studies. Fish the ponds and keep out the ones who are caught several times. Put them in a separate pond and growout. Repeat the process over time and you can have the aggressive offspring.