I don't know about smaller fish eating them, but turtles and crayfish will clean some up, some WILL float, and would be scavenged by birds or 4-legged critters. Yes, the others will decompose and contribute to the nutrient load, but I haven't seen it to cause any problems (yet - this will be my 4th year of playing with them).

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).