Humminbird Side Imaging reveals Wissota ‘gill beds

As I did during my previous guide trip, I spent the tail end of today’s adventure in search of Wissota gills that are starting to populate the shallows in advance of their spawn.

Unfortunately, the shallow bite was non-existent.

So, I began to look deeper, with the help of some fantastic Side Images from a Humminbird 1197c.

The small depressions that you see in this side image are deep water bluegill beds. They are in 14 feet of water at the base of a shoreline dropoff (the brighter area on the left side of the frame). While some are empty (marked with the white arrows), most have a gill standing guard. The presence of the fish is revealed by the white spots sitting in the middle of the beds (contrast the appearance of the empty beds with the full beds, some of which are marked with red arrows).

How do I know these are bluegill beds? Well, those are the only kinds of fish I caught here!

Great post Jason.

I always to it for granted that gills spawned in shallow water, 0-4 foot, and thats just the way it is…..

Jason

Have you ever figured out what the cloud apppearing stuff is in the water colum? I have had it a few times and haven`t figured out what causes it.

Not sure Tom. It’s intermittent for me. I need to do some experimenting with boat speed, direction, etc to see if it originates from the boat. Something tells me that it does.

I have seen things in that center stripe that I know are from the boat. For example, in this screen capture, the white vertical line on the right side of the center stripe is from my kicker. I was pulling cranks while capturing this image. When my kicker is down and running, I see that white line. When it’s up, the white line is gone.

Could the cloud effect merely be scatter from turbulance??
Sheesh on the deep water spawning bluegills. Think that is what populates the lake back once the shallow beds get continually cleaned out day after day after day after day after day, etc. etc. etc.

Jeremy

You’re absolutely right Doc. These are mostly undisturbed fish. I left after catching (and releasing) two big gills….just enough to convince me that I was looking at gill beds and not smallie beds. Protecting these fish is important, as they tend to be the larger members of the gill population, and because they have to take up the slack from the shallow fish that are picked off on a regular basis.

I will add this….once I learned to interpret these images, I was spotting lots of deep spawning beds in similar areas (depths, bottom content). I’d go so far as to say that there are far more deep spawners, at least on Wissota, than a person might otherwise think.

Just a side question Jason, does Wissota have the 10 fish limit on panfish like many of the other lakes? With the advent of GPS and aquaviews, it was a good move for Menomin and other lakes as the technology allows us to be so much more efficent.
I see side imaging in my near future.
Great posts!

Jeremy

There is currently no reduced bag limit on Wissota for panfish.

I would agree that selectively reducing panfish limits makes sense… Minnesota has really reduced the panfish limits in recent years, as well as WI in some instances, most times on a lake-by-lake basis. Multiple anglers taking home literally bucketfulls of panfish isn’t without consequense anymore. An occasional fish fry is great.. But an icebox full of 6 month old freezer-burned filets is a waste. Selective harvest certainly has its merits (especially as it applies to adult fish, including panfish species), even moreso as technology increases efficiency as you pointed out.

Are you sure those are spawning beds and not just rocks that happen to have bluegills on/around them?

I would think a bed would look more line an indentation with some shadowing where as those look like bumps.

Cool images regardless.

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Are you sure those are spawning beds and not just rocks that happen to have bluegills on/around them?

I would think a bed would look more line an indentation with some shadowing where as those look like bumps.

Cool images regardless.

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Compared to what I see with my 997, I’d have to agree with Jason. They appear to be indentations to me. I see some shadowing in some of the beds.

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Are you sure those are spawning beds and not just rocks that happen to have bluegills on/around them?

I would think a bed would look more line an indentation with some shadowing where as those look like bumps.

Cool images regardless.

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Compared to what I see with my 997, I’d have to agree with Jason. They appear to be indentations to me. I see some shadowing in some of the beds.

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Looks like shadowing from rocks like I’ve seen on my 981 and don’t bluegill spawn after bass, let alone in 14ft of water?

Don’t get me wrong, I don’t know Wissota, maybe it’s a warmer lake than most but I thought ‘gills like 70-75 degree water for spawning.

It looks like a possibly sandy area, which would invite the gills. Its a little lesser known, but often gills will indeed spawn deeper than people think, especially when you might be talking about larger lakes or main lake shorelines. Water temps are probably mid 60’s right now (anyone catch the temp in the last couple of days?), so I assume that the gills are pre-spawn, making beds and in preparation mode, but not yet guarding fry or eggs.

Most of the shadowing in the holes is on the boat-path side of the image.. Which would be more indicative of a divot. (Higher closer edge, dip with shadow, then stronger white return as the far edge of the divot slopes back upwards) If the shadowing was more towards the outside screen edge, I would guess more of a bump-rock type of feature causing a white mark with a farther shadow.

I could be wrong.

Mike

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Are you sure those are spawning beds and not just rocks that happen to have bluegills on/around them?

I would think a bed would look more line an indentation with some shadowing where as those look like bumps.

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I really think these are depressions rather than humps.

This image is of the same area, taken with my boat closer to the beds so the side image is more “upright” rather than off to the side, if you know what I mean. In this image, since the beds are closer to the boat, there isn’t as distinct a shadowing on the side of the bed closer to the boat. In fact, most of what you see in this image are white spots….fish. Are they all gills? I dunno….but at least two of them were.

Looking at both images, I’m not sure the shadowing was from anything other than the fish themselves.

If there are beds in 14ft there should be beds up shallow too, right? Are you seeing that?

Whatever it is, cool images.

What seals it for me (depressions vs. humps) is this image, a zoomed in portion of the original posted above. Take a look at the 4 objects noted by the white arrows. Note that the dark portion of each is on their right sides…..closest to the boat.

Take a look at the little cartoon I made. The bottom is in brown, including the depression in the middle. The SI sonar is indicated by the blue lines, which interact with the bottom at an angle defined by the distance of the bottom from the boat. Because these depressions are to the left of the boat, the sides of the depressions closest to the boat are in a little sonar shadow produced by the side of the depression closest to the boat. The opposite side of the depression is imaged well (actually appearing slightly brighter than the surrounding bottom) because it is fully exposed to the SI sonar beam.

If these were humps rather than depressions, the order of the bright and dark features should be reversed on this side of the boat. The hump should appear bright, and behind it (to the left) should be the shadow from that hump. In the depression, the dark shadow appears first (on the right) followed by a brighter spot to the left.

You’re absolutely right, for some reason, I thought this was a right side image. (I think it was your white arrows pointing to the right )

I still would be surpised that ‘gills are spawning this early, especially at that depth, this early.

Nope, it’s the left side image.

Here’s the original, without anything cropped out.

Our water temp is down over the past few days….down into the lower 60s. The shallow fish that were just starting to come up when temps were creeping towards 68 have moved deeper or just boogied in general. I don’t know if the surface temp drop impacted these deep gills because I didn’t find them until yesterday.

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You’re absolutely right, for some reason, I thought this was a right side image.

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That makes perfect sense why you were thinking they were rocks. Orientation is key.

Looks like more beds to the right of that image, in slightly deeper water… correct, or are you thinking those marks are something else?

Mike

I think you’re right Mike, although I didn’t take the time to investigate them further.

It might help some to interpret SI pics is think of the SI beam as light from a flash light. Shine the light on an object, where are the shadows and bright spots. Bright spots will be in the open ( or harder surface )and receive more light, shadows will be edges or partially blocked light.