Pond Boss Forums POND CONSTRUCTION Creating habitat Why fish cribs work and why they fail

I thought the same thing and talked to Eric for a couple of hours today. here's a reply he gave me a few days ago when I questioned the white material as well. Although we do make some of our cribs with white siding material, it's only about 15% of what we take in. More brown and grey colors seem to be most prevalent in our neck of the woods.
(Eric's response:)

First off, I do my photography in very clear water, so all my observations are from high clarity lakes mainly in Wisconsin and Michigan. All my conclusions are based on these waters.
I can�t say if birch bark or white PVC would have the same effects in the Mississippi River or Toledo Bend reservoir or any other turbid water, because I�ve never gone under the surface in dark water to see if fish behavior is different in those kinds of conditions. I would venture to guess that in dark or turbid water, where color and ambient light is lost quickly, it�s not as significant a factor. That�s my guess-but it�s not based on any observations I�ve personally made.

Here�s what I�ve seen regarding birch trees in clear water lakes. When the white bark is still attached to the tree, small fish tend to avoid it. The reason i think is easy to understand. The dark body of the fish is silhouetted against the birch and easy to see by predators. (other fish, and ospreys & kingfishers from the air) Dark bark, surfaces or backgrounds tend to hide the fish. They blend right in and are camouflaged. This is why fish have dark backs and white bellies. Seen from above, they blend into the lake bottom. Seen from below, they blend into the bright sky/surface.

Eventually the white birch bark wears away and the exposed tree parts are darker and the trees become more of a magnet for fish.

Light sand bottoms where fish would also stand out are also not favored by fish. Darker, mucky or leaf covered bottoms will have more fish for exactly the same reasons.

When you think about a lake system, there�s really nothing that naturally occurs in a lake that�s white. It�s really an alien color to a lake. Sure, there might be very bright, light-colored sand beaches, but these areas if they�re lacking any plants, rocks, or woody debris are typically not areas where fish hang out. Fish by and large are always trying to hide. Hide from predators, and hide from prey. They don�t want to be noticed, so anytime they�re silhouetted against light backgrounds it makes them very visible and vulnerable. If you�re a predator fish, all the potential prey will clearly see you. If you�re a forage fish, you�ll also be highly noticeable. So being seen so easily has no benefits of any kind. I think this is why fish avoid light backgrounds.

Regarding the fishiding structures:

I don�t think the samples I put in Lake Anna tells us much actually.
It�s true that largemouth bass and rock bass have built spawning nests next to the bases and I�ve seen newly hatched fry around them. But they seem to group under a piece of PVC that offers shade from the sun. They seem to position themselves under a panel, if there�s no panel directly underneath it where they are silhouetted.
I�ve also seen Age 1 and 2 bluegills around the fishiding structures in good numbers. This would seem to contradict my previous statements. But these bluegills tend to be almost white.
If you�ve ever fished in really clear water maybe you�re noticed that the fish lack deep coloration. Bluegills especially seem to take on a very light, almost white colored appearance in very clear lakes. The bluegills in Lake Anna have always been very light colored fish lacking any bars or red and olive colorations you typically associate with bluegills. A fish with this color, or lack of pigment would actually blend right in to the white PVC quite well. A darker surface would tend to make these fish stand out, so in this case they seem to be a good match for each other.

It�s important to remember that a key difference between fishiding and the white PVC piping that�s shown in that picture I included, is that the PVC piping doesn�t seem to collect much organic growth. It�s about as white as it was the day it was dropped in the lake. I don�t see green algae clinging to it like it does on your product. I don�t know why more organic material isn�t forming on it the way it does with your fish hiding panels. Perhaps the surface is coated with something, or the curvature has something to do with it. I�m not sure. Maybe you have some ideas. (PVC pipe has an algae prohibitor because it is normally used in sewer/water pipes, thus the reason folks have learned to sand it before sinking.)

You know David, I�ve given a lot of thought to your fishiding structures over the last couple of years. I guess I�m really stuck. I don�t feel like I can whole heartedly endorse them, but at the same time, I can�t dismiss or condemn them either. You seem to be onto something and there does seem to be genuine applications for them. I also don�t feel like my observations of them on a single infertile lake in Wisconsin can be used to gauge their performance or lack of it in other other lakes with different conditions. In 3 weeks, I�ll personally be inspecting the fishidings that Roger placed at two separate locations in Round Lake (Sawyer County, WI). Perhaps observing them and seeing what�s going on with them on a different lake will give us more information that will allow us to make some better conclusions.