Big Indiana Bass

Seems like fishermen are always looking for a good guide to weed identification. I want to pass along a nice and simple website that you can bookmark for future reference. Lake, Lawn and Pond is a website hosted by the SePRO Corp., distributors of Sonar (fluoridone) and several other commonly used aquatic herbicides. The link above will take you to their weed ID page. Simply click on the class of weed you want to ID (emergent, submergent, algae, etc.) and you'll be taken to a page with all the common varieties of aquatic vegetation in easy to decipher pictures. Feel free to also browse other sections of the website while there for some great information.

One thing I do want to specifically mention though. One of the biggest "mistakes" I see anglers make all the time is believing their lake is turning over every spring when they find all kinds of floating chunks of stuff on the waters surface. This typically occurs with water temps in the upper 50's to low 60's, but can vary from lake to lake. What you are seeing is not the result of a spring turnover, but a unique characteristic of a type of algae. Check out the pictures and description of Pithophora algae. This is what you are seeing, and it has nothing to do with your lake turning over.

We're pretty fortunate here in central Indiana to have several bodies of water that are blessed with an abundance of Justicia americana, also known as water willow. If you only talk fishing lingo, you may have frequently heard it referred to as 'Geist weed' or 'rock weed'. We've spoken of it before a couple years back in THIS POST, but a soon to be published paper from some of those same authors came across my desk today and I thought it would be a good topic to revisit.

The research is titled "Effects of American Water Willow Establishment on Density, Growth, Diet, and Condition of Age-0 Largemouth Bass in Kansas Reservoirs", again by Strakosh, et. al. If you read his doctoral dissertation the first time around, you'll have way more details than the linked abstract will provide. If not, read the abstract and see if it sounds interesting, then revisit the links in the original post to get lots of good details, including a lot of practical applications to bass fishing if you 'read between the lines' like I do. After doing so, there should be no surprise as to why 'the factory' (Geist Res.) is such a good fishery.

At present on the lakes you'll only find a bunch of dead and brown weed stems left over from the winter. But within another month or so you'll start noticing some new root nodules forming, along with a greening of shoot tips. Then it's off to the races as the plant grows pretty fast and furious as things heat up. By that time though you should have already popped some nice sacks of bass out of this veggie.

The grass is starting to grow on many lakes, at least the ones that aren't flooded by crazy amounts of water right now. Understanding which type of aquatic vegetation you have can help lead you to better bass fishing. Here are the links to a simple picture guide from the Midwest Aquatic Plant Management Society that covers the most commonly found "weeds" in our waters.

Plant Reference Chart (Pg. 1)

Plant Reference Chart (Pg. 2)

The local lake just received an application of Aquathol K. One of the questions that arose was whether the timing of the treatment relative to the spawning season was going to be a problem. New research out suggests no negative effects on largemouth bass spawning:

Impacts of Aquathol K Applications on Largemouth Bass Spawning Behavior and Production of Young Fish

Mike Maceina, Department of Fisheries, Auburn University, Alabama

The first year of a two year project that examined the effects of direct spraying of Aquathol K on nesting largemouth bass in small ponds was completed. Aquathol K was applied at the approved rate of 3 ppm in three 0.1 hectare ponds in March 2005 as largemouth bass initiated spawning. Water was applied in a similar fashion to three other 0.1 hectare ponds. Aquathol K did not impact largemouth bass nesting activity; spawning behavior and activity was similar to ponds treated with water. Production and growth of young largemouth bass measured after spawning ended was similar between ponds treated with Aquathol K and control ponds.

This lake is scheduled to receive a Sonar treatment a little later in the year. Several studies on both of these compounds and their effects on largemouth bass were previously covered in the following post: More Veggie Research

It has been a while since we last talked vegetation. This is always a hot topic of discussion in bassin circles, especially down in the SE portion of the country. However, even in Indiana we get some heated discussions and finger pointing going on from time to time whenever there are weed treatments being done on a particular lake. So I have a trio of papers (in full) for everyone to browse.

• Effect of Aquathol K Treatments on Activity Patterns of Largemouth Bass in Two Coves of Lake Seminole, Georgia - Aquathol K is actually a form of Endothall acids and is frequently used on hydrilla. Endothall herbicides interfere with plant respiration by affecting lipid and protein biosynthesis, and disrupting plant cell membranes. It is largely considered a contact herbicide. In this study they radio-tagged and tracked 30 largemouth bass both pre- and post-treatment. Ultimately effect on largemouth bass behavior was minimal. Bass did not change their locations due to treatment and no bass ever left a home area (or cove) after treatment. The only noticeable change was a general pattern of shallower occupancy of bass post treatment. 
• Aquatic Vegetation, Largemouth Bass and Water Quality Responses to Low-dose Fluridone Two Years Post Treatment - Fluoridone is the compound name for Sonar, a systemic herbicide that works by inhibiting carotenoid synthesis. It is very expensive, but also very effective when used according to labeling recommendations. It is most frequently used on submerged invasive vegetation such as milfoil but has other cross-functional applications. In this study they used a low dose of fluoridone (5-8 ppb) to selectively treat milfoil without affecting accompanying native vegetation and then studied the effects of this treatment on largemouth bass and water quality. There were no negative effects on either, though results were variable due to lake morphometry. There was also a small bump in growth of small bass, however since it was a short term study (2-years) the bigger question would be what if any long term effects might be seen from either a single treatment or a series of treatments.
• Population Characteristics of Largemouth Bass Associated with Changes in Abundance of Submersed Aquatic Vegetation in Lake Seminole, Georgia - Another fluoridone (Sonar) treatment of hydrilla in various embayments of Lake Seminole. This time a 5-year study between 1998-2003. After treatment, growth of bass in 2 of the 4 age groups studied increased 3-7% compared to control locations. This increase in growth rate also increased egg production, nearly doubling in the treatment area. There was a 20%+ decline in mean annual survival, but this persisted in the control sites also suggesting that the result was not related to the actual treatment. This paper has a very nice write-up in the results and discussion section that refers to several other studies and poses questions that would be interesting to try and answer with future studies.

There are lots of studies being done on aquatic vegetation and its relationship with fish populations, largemouth bass included. I find it particularly interesting how fisherman's opinions and perceptions tend to vary considerably against some of the published studies as to what constitutes good weeds or bad, or how many or how much weed growth is good as relates to bass fishing and bass populations. It is obviously a very intricate and "tangled web" at times. Passions and opinions can fuel some pretty good debate, and the debate can get pretty heated at times. That aside, I came across this interesting piece today concerning diets of largemouth bass as relates to being "habitated" to two different weed types.

Largemouth Bass Diets in Two Aquatic Plant Communities

In this study, it clearly demonstrated a shift in diet ontogeny toward preyfish and away from invertebrates when bass were "housed" in exotic milfoil versus native pondweed. This is significant in the respect that it has been shown that the earlier a predatory species can shift it's diet to preyfish, the better its growth potential and survival. This has been documented not just in largemouth bass, but crappie as well. Here is one article documenting this fact:

Ontogenetic niche shifts in largemouth bass: variability and consequences for first-year growth

So chalk one up for the invasives. As I mentioned, it's a very complex world out there when dealing with vegetative issues and studies. This may or may not prove anything in the big picture, but like everything else, it adds to the greater discussion. I'll be sure and post quite a few more vegetative pieces over the next few months from both "sides" of the fence.