Structure Question - Depth Breaklines on Natural Lakes

[Bass_Fischer]

When chasing LMB in large weedy natural lakes with tons of structure across all depth zones, are there any 'old reliable' rules of thumb that can help differentiate good breaklines (depth) from excellent breaklines from incredible breaklines?  I've wondered about correlating water clarity to depth (perhaps adding some consideration of weather?) or maybe a specific size of drop from/to certain depths but haven't come up with anything good enough to qualify as a ROT.  Any suggestions?

Rick
 

[WRB]

First things first. You are located in MN that has 3 basic natural lake types.

1.Oligotropic

2. Mesotrophic 

3. Eutrophic 

Look up those terms so you know what type of lake you are fishing.

The majority of northern bass lakes are #2 Mesotrophic, with further north Canadian Shield Smallmouth bass lakes being #1 Oligotrophic.

The difference between these lakes is age and bottom composition or structure elements.

Tell us what type of lake so we can focus on what maybe helpful.

Tom

[papajoe222]

Natural lakes rarely have a ton of obvious structure, so you need to be able to identify those subtle structural elements first off. Secondly, you need an understanding of bass and predominate forage seasonal movements. 

Bass prefer quick access to shallow feeding areas in the post fall to early spring season, so look for steeper banks and drop offs shown as depth controur lines close together. Prespawn will get them moving toward potential spawning sights with easy access back to deeper water. Slow tapering points are a prime structure then. Hopeflully, you know where they spawn, so look for them to drop back from the spawning area after the spawn. The first significant drop out from the spawning flat.  From there, they'll make their move to their summer areas and whether that's shallow cover, or deep water structure, access to a steady food supply is a necessity.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

b

[MN Fisher]

33 minutes ago, WRB said:

The difference between these lakes is age and bottom composition or structure elements.

Tell us what type of lake so we can focus on what maybe helpful.

If he's fishing Minnetonka, it's a eutrophic lake according to MN-DNR. The structure is there, but not abundant...see the bay I normally fish

 

Finding the bass can take a while, even though it's a highly rated bass lake. Diligent searching with sonar is almost required.

 

My best LMB last year came from this bay, middle of the summer - right about where the '10' at the bottom of the map is...not far from the launch.

[Bass_Fischer]

Yup, Tonka.  Primary LMB forage is bluegill and crappie, with a few areas holding craws but the smallies have been steadily taking those areas over.

 

MN Fisher..  That best LMB last year, you'd call that a point fish, yes?  Were you just probing that southern (depth) breakline when you got her?  10' in that bay had to be pretty weed-choked, yes?  Was that a factor in your location strategy?

 

And since we're sharing, my best last year came here, near the main body on a dropshot.  She was up near that mini-hump (13/14') on this pretty saddle.  Not too weedy but still seemed to have all the needed ingredients including depth and some interesting contour irregularities nearby..

 

[MN Fisher]

3 minutes ago, Bass_Fischer said:

MN Fisher..  That best LMB last year, you'd call that a point fish, yes?  Were you just probing that southern (depth) breakline when you got her?  10' in that bay had to be pretty weed-choked, yes?  Was that a factor in your location strategy?

Actually - I was rolling a spinnerbait with trailer past a patch of lily pads just to the west of that 'point'. Bass came out of the pads to hit the lure. Weeds next to the pads had tops about 1'-2' under the surface, water was slightly stained, sun was up...was looking for something in the pads - if the spinner hadn't worked I was going to try either pitching into them or running a frog across the top.

7 minutes ago, Bass_Fischer said:

And since we're sharing, my best last year came here, near the main body.  She was up near that mini-hump (13/14') on this pretty saddle.  Not too weedy but still seemed to have all the needed ingredients..

Sorry - that pic didn't come through. Ya, mini-humps are about the best structure on the lake - at least in North Arm and Phelps Bay where I do most of my fishing.

[WRB]

Structurally this lake has some prominate features.

1. The major point the divides the main lake basin near the launch ramp.

2. The secondary main lake underwater point up lake following the red line on the left side there appears to be a small hump that tops out at 10'.

I would start by following the 8' to 10' break line looking for isolated structure elements that may hold baitfish and bass. Work up and down shallower and deeper to a depth preference is established.

Weed lines are more then likely seasonal and the deepest basins may be void of dissolved oxygen unless springs are present.

The good map posted will give us something to use.

Tom

 

[MN Fisher]

7 hours ago, WRB said:

Structurally this lake has some prominate features.

That's is just one bay of the lake, Tom. On this map, it's the one of the pair left of center at the top. Tonka is actually a group of Kettle Lakes, formed end of the last ice age, joined by channels.

[mc6524]

Several things come into play but many of us fisherman continue to be confused between the difference between structure and cover.  Structure is the big picture part of the lake.  Such things as dropoff’s, channel bends, transition from rock to gravel, etc.  cover on the other hand is more specific like lay downs,, trees, grass etc.   Our challenge on any given day is to match these two together to develop a pattern.  To do that we then need to match the seasonal pattern with the structure and cover.  For example, a summer pattern may be fishing deeper main lake points that have a channel bend with pea gravel.  Now you know why on some days they are so hard to catch ? 

[Bass_Fischer]

9 hours ago, MN Fisher said:

Sorry - that pic didn't come through.

Trying again..

 

[WRB]

I have about limited experience with Canadian Shield natural lakes mostly around Lake of the Woods region Ontario Canada during summer periods. California has very few natural bass lakes, Clear Lake being the primary natural lake.

Southern made made impoundments are reserviors that flood terrian leaving underwater structure elements not found in natural lakes and the aquatic plant growth is different. No standing timber or creek channels for examples.

cover like docks are common and a few blow downs and beaver houses.

In-Fisherman has some good natural lake information including weed types, grass is called weeds up north.

Very interesting group of lakes. When I get some time to study the map will try to put my limited knowledge Shield lakes to locate promising structure elements, can't do much about the cover without being on the water.

Tom 

[MN Fisher]

6 minutes ago, WRB said:

Very interesting group of lakes. When I get some time to study the map will try to put my limited knowledge Shield lakes to locate promising structure elements, can't do much about the cover without being on the water.

For more detailed look - i-Boating : Free Marine Navigation Charts & Fishing Maps  - this links you right to the scalable map of Minnetonka. Scroll-wheel to zoom in/out, click and drag to move about. This is the map I use with the app on my tablet when I'm on the water.

[gim]

4 hours ago, MN Fisher said:

joined by channels.

Most of those are man-made.

[MN Fisher]

19 minutes ago, gimruis said:

Most of those are man-made.

To replace other natural channels due to position or land ownership. Case in point. The Narrows WAS a small stream flowing from Carmen into Lafayette...weed choked, it still allowed small boats passage. It was dredged a couple of times to improve traffic flow, until in 1884 a new channel was dug slightly north of the original one. That is the Narrows as it is today. So - man-made, yes. Done solely to create the lake from smaller lakes...no.

http://lakeminnetonka.com/about/local-lore/a-history-of-the-narrows/

 

Channels at Arcola Bridge and Seton Lake/Harrison Bay Bridge were shored up and widened...but not dug as 'new' construction.

Black Lake channel and Emerald Lake channel have always existed - you cross the bridge at either and you're on Phelps Island...which WAS an island until the bridges were built.

 

[Paul Roberts]

On 1/8/2020 at 9:02 PM, Bass_Fischer said:

When chasing LMB in large weedy natural lakes with tons of structure across all depth zones, are there any 'old reliable' rules of thumb that can help differentiate good breaklines (depth) from excellent breaklines from incredible breaklines?  I've wondered about correlating water clarity to depth (perhaps adding some consideration of weather?) or maybe a specific size of drop from/to certain depths but haven't come up with anything good enough to qualify as a ROT.  Any suggestions?

Rick
 

Hi, Rick. You are on the right track. Here's my general breakdown —my way of organizing the search— for homing in on “excellent” spots, and hopefully, “incredible” spots —what I call “Carnage Zones”:

 

The starting point in terms of depth use by bass is generally water clarity, as you suspected. This is bc light penetration determines the depth limits of primary production —the foundation of the food chain. The clearer the water the deeper livelihoods can be made. But not every species can make livings just anywhere, even within that photic zone.

 

So… the next question is available forage. Each species has different requirements that may or may not jive with bass's requirements —at least all the time— although few predators are as adaptable/versatile as bass; They tend to make use of whatever forage is there. Here, water temps and habitat type at those depths determine who lives where.

 

Next is vulnerable prey, something many anglers don’t fully appreciate the importance of. Prey is not "food" until it's been found, captured, handled, and ingested. Structural characteristics (structure, cover, objects), and existing conditions and circumstances, determine the likely result of predator-prey interactions —and the likelihood that bass will revisit an area, and how often. Bass both intuitively recognize, and further learn, where and when prey are most likely to be vulnerable.

 

Finding Carnage Zones —the holy grail in fishing and, in fact, for each rung in the food chain— is a matter of location and timing —those same where's and when's the fish are looking for. This requires intimacy with the particular water body. As we narrow things down, in time and place, things get more chaotic —dicier. That’s fishing. In fact, that’s pretty much… everything. It appear to be the way of the known universe. Thank the powers that be for obsession —that is, drive and perseverance.

 

Flirting deeper into the chaos, narrowing things down to the nub, is the proverbial “spot-on-the-spot”. Structural characteristics, from a fish’s perspective, mean two main things:

 -Large scale topographical structures of importance are the “food shelves” (depth of these functionally determined by water clarity).

 -Smaller scale “objects” which fish —bass esp— relate to, or are meaningful to the fish. Physical “objects” that fish can make use of to hide in or make kills off of: logs, rocks, weed walls, the bottom, the surface, current seams, turbidity lines, even shadows...

“Structure” is the ballpark, the playing field. “Objects” are the bases (1st, 2nd, 3rd…), etc…, where things intersect —where the action is. I suppose we could see the ball as the chaotic “timing” element, if you care to follow my analogy.

 

Hope this helps put things into perspective. It’s a big job. And we’re just the monkeys to do it! No wonder some love baseball almost as much as we love fishing!  Notice I said "almost".