I spend between 100 and 200 hours under water each year, a fair amount of that time observing fish and other aquatic behavior. The vast majority of this time is in clear ocean water, but would like to do some more in the pond next summer if it clears up enough to see anything.
One particular behavior of certain species of fish is something called "flashing". It is nothing more than them coming up close to something, and quickly using their momentum to rub up against that item. I assume it is to attempt to remove parasites, or do something similar to what a cow does when rubbing up against a tree or a dog scratching .
Where I'm at now, along about a half hour before sunset, Creole Wrasse by the tens of thousands form a line of loosely a few fish wide and deep and like a conveyor belt they travel to what I have to assume is their nite time sleeping area. This conveyor belt of fish can go on for an hour or so.
They swim by in this continuous "school". Certain sponges they somehow choose to "flash" against. Not every fish uses this chosen "flashing" point, but maybe one out of every 50 or 100 will pull out of the school momentarily, "flash" against this purple tube sponge, and jump back in line and continue on with the rest. I've hovered in the water for ten minutes at a time watching this one sponge get "flashed" against. Sometimes the sponge will actually get a slick appearance it has been rubbed up against so much by the fish. There are other species that also flash against things, but there are just so many Creole Wrasse and they do it so obvious and repeatedly that the behavior is so much more noticeable than other species. There might be a Wrasse flash against a certain sponge every 4 or 5 seconds.
I'm getting to the point. Slowly, but I'm getting there.
What I'm wondering, is what would happen if a person put a cattle salt block or blocks in a pond in a few feet of water. Would BG or LMB use it as a rubbing block or "flashing" point?
It has been discussed here on PBF the benefit of salt in the water. It has also been discussed about the number of gallons a pond might contain and how many truck loads of salt it would take to actually make any difference in the water salt concentration.
But what if a person provided a concentrated area of salt water? Like a square cattle salt lick block sitting in the water? Wonder how many days it would take the salt block (either white or mineral) to dissolve and go away? Wonder if it would provide a high salt concentration zone within a half inch of the block? Wonder if fish with parasites or other skin/scale problems would use it as a "flashing" block? Wonder if it would provide any benefit at all?
Would it hurt anything to throw a half dozen cattle salt blocks in the pond?
Maybe too much time on my hands to ponder such things?
utube clip of Creole Wrasse 
