Where Are The Bass In This Lake?

[Paul Roberts]

Talking of structure and related stuff...

 

I have radio-telemetry data for this lake. Thought we'd reverse engineer the bass habitat in this lake together.

 

Where would you expect to find the bass during summer in this lake? Assume that you are going to fish this lake for the first time and these images are part of your research. What's important in making such an appraisal? What questions might you ask yourself?

 

Our lake is a 60acre water retention/irrigation reservoir that is not used for irrigation anymore. Water levels do not appreciably fluctuate; there is no annual drawdown. It is 17ft at the deepest point. Visibility is about 6ft (by Secchi disk). Mean 24hr surface temps are 75-81F during summer.

 

This first image provides depth, sans cover, with depths in feet coded by color gradation. I'll then supply a satellite view that shows further detail (cover). Then I'll reveal the known bass locations.

 

My FIRST question is: “What can we say by just looking at the basin –sans cover?

 

Where do the bass live? Where are the likely sancuaries/homes/bedrooms? Where are the likely feeding grounds? What’s most important to bass in summer? What factors might influence this?

 

Have fun with this folks.

[Ozark_Basser]

Edit: Sorry. My last entry was for winter. Did you change that too, Paul? I still haven't been to sleep so it could just be me. For summer, my answer will change considerably. I choose my number one spots as the north and south ends of the lake solely due to the fact that is where I think the most bait will be with the best between the two being the one with the most cover. I still will consider the spot with two humps and two depressions as a good spot though along with the points especially if there is a good population of shad in the lake.

I still say the shallows above all else due to the fact it's a small body of water where bass rarely ever seem to leave the shallows compared to larger reservoirs. That's my bet. Shallows. In particular, the shallows with the most cover. If cover is sparse, I'd bet money on the north flat adjacent to deeper water.

Edited January 19, 2015 by Toad Mode

[scaleface]

The    flats to the north of the deepest water and a point with humps like Toad pointed out  .  Thats an interesting area .  Likely gets fished to death , though.

 

Edited:  All the indention's of the purple/ blue areas are high points that Id try . 

[Lund Explorer]

I'm going to go out on a limb here and assume that this is a trick question.

[livetofish28]

In the water

Tight lines

Andrew

[papajoe222]

This time of year I would concentrate in the dam area where the drop is 45 or steeper.

[Dwight Hottle]

Based on the limited intel offered so far I would start my search in the deeper water located in the middle of the reservoir. Graph the light blue water, dark blue to pink/fucia water. Since we don't know the geographic location that would be my starting point.  

[basscatcher8]

In the middle of summer I would start where ever the ridge of the blue in the middle gets the closest to shore. Shallow water with easy access to deep water close by. If that didnt pan out I'd hit the shallow cover that you described in the OP that we haven't seen yet. And that flat south of the hole that comes to a point would be an area to look at as well.

[scaleface]

Those two humps right next to the two depressions. I wonder if they are manmade ?

[Ozark_Basser]

Those two humps right next to the two depressions. I wonder if they are manmade ?

Probably not I would guess. If you think about it in terms of the size of the lake compared to the size of the humps, they are pretty big. I could see a couple of brushpiles being placed here or there, but something of that size I would guess is natural. The humps probably aren't as defined as they seem on this map either.

[Paul Roberts]

Good start.

 

Dwight, I put summer water temps in to offer a clue on latitude. Spawn occurs last week in Apr/1st week in May in a lake this size.

[RoLo]

If it provides suitable cover (weedy or woody), the topography at "+" could be a year-round site.

I like it because the northeast bay is a sizable food-shelf & bedding flat, and its southern perimeter lies in fair proximity to the lake basin. 

 

It also appears that a couple of indistinct humps with 4-ft crests lie north of the lake basin, which could have seasonal interest.

 

All bottom contour aside, the "headwaters" to the south might provide the best weedbeds,

because the water farthest from the dam is generally the most turbid and fertile. 

 

Roger

 

[Paul Roberts]

Questions you guys asked:

 

Prey species: Bluegills and yellow perch.

 

Substrate: Will provide that with the “cover” image.

 

Public fishery. No boats allowed. But for our fantasy purposes, we'll have run of it.

[scaleface]

If no boats allowed then how do you know the known bass locations ? 

[Catt]

I aint gonna play til I see more details

[senile1]

Without much detail to go on, my thoughts fall in line with Roger's with respect to the huge flat in the Northeast corner and its connection to the large deep basin.  I could also see the smaller flat to the south of the dam and the basin being used to a lesser extent.  The point on that flat closest to the dam and furthest to the left drops more quickly and is closer to the deepest water in the lake.  That flat appears to be four feet deep for the most part.  However, other details when provided could completely change my thinking.  As Catt was indirectly alluding to, more information is needed.

 

To provide a counterpoint to my first paragraph, interestingly enough, there is a lake about 45 miles from me that is very similar to this one in size (55 acres) and flat locations.  A 9 - 14 foot creek channel leads from a basin (21 feet at its deepest) to the upper end of the lake.  There are larger flats to the right and left of the dam which have the quickest access to the deepest water at this lake, but the greatest concentration of bass seem to use the extensive flats in the upper end and use the creek channel to make depth changes.  I believe the reason for this is due to a greater concentration of vegetation at the upper end and along the creek channel, leading to a greater concentration of forage which is mainly bluegill.  The flats near the dam have far less vegetation and some wood.  I have a hard copy of a topographical map for this lake which I can scan and add later.  I have been unable to find it online for a few years now. 

[Paul Roberts]

Roger, and Senile1, now that’s the spirit!

 

Of course more info is needed. I guess my FIRST question was/is, “What can we say by just looking at the basin –sans cover?"

 

I’m not just asking where would you fish, exactly. I’m asking where do the bass live? Where are the likely sanctuaries/homes/bedrooms? Where are the likely feeding grounds/kitchens? What’s most important to bass in summer? What factors might influence things? I’ve provided:

 

-a basin map

-water clarity (~6ft by Secchi)

-mean surface temps (75-81F)

-prey species (mainly bluegill, few yellow perch)

-And I’ll add that there is a competing predator –northern pike.

 

And I’ll provide some cover info:

 

-Substrate is rubble beneath, mostly covered in silt. The dam is faced with modest sized rip-rap.

 

-There is precious little wood –the remnants of smallish deadfalls near shore here and there.

 

-Vegetation present is Eurasian milfoil (Myriophyllum sibiricum), coontail (Ceratophyllum demersum), longleaf pondweed (Potamogeton nodosus), and sandgrass/muskgrass (Chara sp).

[Matthew2000]

I think they tend to navigate more towards the water that time of year.

[A-Jay]

"Vegetation present is Eurasian milfoil (Myriophyllum sibiricum), coontail (Ceratophyllum demersum), longleaf pondweed (Potamogeton nodosus), and sandgrass/muskgrass (Chara sp)"

 

Leaving the banks to other anglers I'd prefer to probe a little deeper.

 

The front and back side of decent sized or even isolated weedlines is a good place to start. 

Spots where the vegetation ends that are close to the deepest water are good.

  An Open spot in a larger vegetation field can be good especially if it has a harder bottom, some type of cover on it and is near the deeper water.  The inside turns, indentations and "points" formed by the vegetation all get waypoints right off the bat.

 

So I'd start by poking around where the light blue and the dark blue meet - the 9-12 foot zone; then move in or out as the depth of the weedline changes.

 

A-Jay

[Ozark_Basser]

My answer still remains the shallows on whichever part of he lake has the most abundant amount of foliage which I think would probably be either the north or south ends of this lake.

[senile1]

With respect to the areas I pointed out in my previous post, I wanted to clarify that I was referring to structures used to move from shallow to deep and vice versa. I did not mean to indicate that the flats are where I would spend most of my time fishing in the summer.

Paul, thanks for the info about the northern pike. I think the bass will try to avoid them and will stay close to the milfoil and coontail on the structures they use. In summer I would be concentrating on the deeper weeds and weedlines though I wouldn't ignore other areas along the structure from shallow to deep, depending on the weather conditions.

[Team9nine]

I guess my FIRST question was/is, “What can we say by just looking at the basin –sans cover?"

 

I’m asking where do the bass live? Where are the likely sanctuaries/homes/bedrooms? Where are the likely feeding grounds/kitchens? What’s most important to bass in summer? What factors might influence things? I’ve provided:

 

-a basin map

-water clarity (~6ft by Secchi)

-mean surface temps (75-81F)

-prey species (mainly bluegill, few yellow perch)

-And I’ll add that there is a competing predator –northern pike.

 

And I’ll provide some cover info:

 

-Substrate is rubble beneath, mostly covered in silt. The dam is faced with modest sized rip-rap.

 

-There is precious little wood –the remnants of smallish deadfalls near shore here and there.

 

-Vegetation present is Eurasian milfoil (Myriophyllum sibiricum), coontail (Ceratophyllum demersum), longleaf pondweed (Potamogeton nodosus), and sandgrass/muskgrass (Chara sp).

 

Alright - a few thoughts based on the above:

 

• 6' Sechi is pretty clear, meaning the vegetation present probably extends and covers a large majority of this reservoir. Milfoil would likely be in the silty portions of reservoir, largely confined to the littoral zone at depths of 6'-8' or less. The pondweed is probably similar, but the muskgrass would likely be in deeper depths beyond the other two, and in areas that are less silted in - possibly appearing all the way out to the 17' max depth. All the "grass" would help with the filtering of water, and would help explain the good sechi reading despite the silt.
• The silt would suggest some type of runoff or murky input, perhaps from farmland or perhaps from adjacent meadows. Likely not forested in the area since the comment of "precious little wood," Non-forested would also help explain the siltiness since there would be less watershed protection.
• The water temps and the reference to pike and perch is interesting from several standpoints. Being coolwater species, the pike probably roam the deep open water as well as the deep weedline for much of the summer, thereby forcing many of the smaller bass shallow in this lake, likely into the pondweed and milfoil. Larger bass could survive amongst "snakes," but that would also somewhat depend upon the overall pike size structure. Still, I'd expect some nice sized bass in deep open water, but the majority of bass to stay shallow. Bluegill would be similar, with most being confined to the littoral areas or the inside weedline (or inside the weedbeds). Perch would likely stay out in the sandgrass in somewhat deeper water, and likely from the deep weedline out. Like pike, they prefer cool water temps with good oxygen in the summer.
• About the oxygen and cool temps, this lake is probably higher altitude or certainly farther north, likely 40 degree north latitude or better. As such, a thermocline is unlikely (also based on the given summer temps if those are maxes), which is what allows the perch and pike refuge and the ability to survive in this lake.
• The pike probably spawn in in any marshy bay areas present, while the perch will spawn along dead weed stems and the available scattered wood in the shallows. Bass and bluegill would likely spawn just on the inside weedline in slightly deeper water due to the overall clarity.
• Due to the silt mention, it also wouldn't surprise me to find a decent population of bass up what appears to be a tributary arm. That is likely murkier overall, with more scattered vegetation, and would help the bass and bluegill avoid pike predation in this lake.

That's all I can think of for now.

 

-T9

[RoLo]

Roger, and Senile1, now that’s the spirit!

 

-water clarity (~6ft by Secchi)

 

-prey species (mainly bluegill, few yellow perch)

 

-And I’ll add that there is a competing predator –northern pike.

 

-Vegetation present is Eurasian milfoil (Myriophyllum sibiricum), coontail (Ceratophyllum demersum), longleaf pondweed (Potamogeton nodosus), and sandgrass/muskgrass (Chara sp).

 

My original response was based on 'bottom contour', which by itself can keep the angler on the right side of the law.

The addition of new limnological and biological data will naturally put constraints on bass location.

 

A secchi depth of 6 feet indicates 'clear' water, which would encourage me to fish away from the dam,

where water clarity might be more user-unfriendly.

 

Technically speaking, 'chara' (muskgrass) is not a true plant, but a high form of algae very similar to 'nitella' (stonewort).

Nevertheless, bass find these unrooted, bottom-clingers very attractive (nitella & chara).

Still and all, I wouldn't consider either algae form as a game-changer.

 

With respect to largemouth bass, I don't envision separate lake regions for breeding, foraging and refuge,

but look for year-round sites that can satisfy all their needs. The 'daily migration' theory of bass is not supported

by telemetry studies, nor is it supported by Mother Nature herself. Largemouth bass possess a swim bladder,

an organ devised to maintain neutral buoyancy. Furthermore, when you fillet a migratory fish you will always find

a dark bloodshot median, which supplies oxygenated blood needed for daily migration. The median flesh band

of largemouth bass is flaky white, which strongly suggests a residential homebody. It stands to reason,

that a residential fish would strive to compress breeding, foraging and refuge into one common area

(year-round holding site). In some lakes their wish can be granted, in other lakes it cannot.

 

In waterbodies shared by both largemouth bass and northern pike, the "pike" is deemed the dominant predator.

The test lake contains longleaf pondweed (cabbage), which certainly lends to a pike population,

and to a greater extent if broadleaf cabbage was also present (P. amplifolius). In addition, if this lake contains

populations of high-fat pelagic prey like alewives, smelt, herring or ciscoes, then bass location would almost certainly

be dictated by pike. In lakes shared by bass and a sound population of large pike, the main biomass of largemouth bass will typically inhabit the littoral zone between the shoreline and 10-ft contour line. An excellent example is Lake Huron's Georgian Bay where bass fishing is tremendous, but confined to peripheral coves and back-sloughs.

Nevertheless, since bass are basically homebodies, this causes no real hardship.

 

Gamefish are 'opportunistic' predators, and bluegills are 'ubiquitous'. Consequently, bluegills generally get

far more credit then they rightfully deserve. Given a choice, gamefish prefer soft-finned baitfish like shiners,

dace, minnows & shad, more so than spiny-rayed forage like bluegills & perch. Based on stomach contents,

yellow perch constitute by far the highest percentage of the northern pike's diet. Based on angler success however,

soft-finned baitfish such as chubs, shiners & even frozen smelt will far outperform a live yellow perch on the hook,

which come in dead last.  In other words, it's very difficult to differentiate 'Preference' from 'Availability'. 

 

Roger

[Paul Roberts]

OK…let’s “flesh” this out a bit more… add the next skin –cover. It’s pretty apparent that lake basin alone tells us only so much –the ballpark but nothing about the playing field or the players.

 

I was originally planning to add higher ecological community info later, as a third “layer”, but got ahead of myself. I didn’t want this thread to feel like a quiz. Instead I meant it as an instructive way of introducing fishing lake intel in terms of layers of information. Those layers are: structure (basin topography), substrate and cover (“edge” or niche complexity), and finally the players (the food chain).

 

What’s interesting about this satellite image is that you can see the riverine shape of this little reservoir nicely. There was no “river” here, just a “wash”. Obviously the image was shot on a nice cloudless day.

 

Once again:

 

-Water clarity (~6ft by Secchi when measured)

 

-Mean summer surface temps (75-81F)

 

-Substrate is rubble beneath, mostly covered in silt. The dam is faced with modest sized rip-rap. No boulders, beyond the dam face rip-rap. The surrounding land is plain (once short-grass prairie).

 

-There is precious little wood –the remnants of smallish deadfalls near shore here and there.

 

-Vegetation present is Eurasian milfoil (Myriophyllum sibiricum), coontail (Ceratophyllum demersum), longleaf pondweed (Potamogeton nodosus), and sandgrass/muskgrass (Chara sp). Echoing T9 above: Clarity is adequate for light-loving milfoil, so its weedline is at ~8ft –about milfoil’s max depth in the region. Coontail can reach a little bit deeper. Chara can grow as deep as 20ft. but grows no more than 3ft tall and thins out quickly at the tops. Longleaf, an emergent “cabbage”, can root no deeper than about 4ft or so.

 

-Fish species: Largemouth bass, northern pike, bluegill, few yellow perch.

 

OK. Where are the bass here in summer? What looks good and why?

 

[Ozark_Basser]

I think the north end will hold a good deal of bass, but the south end is the best due to what appears to be multiple types of grass with numerous small openings and transitions. It also looks as though it would look better underwater than the north end as far as within the cover goes, and it would hold more bluegill. The rest of the lake I'd leave to the pike.