Check to see if the products contain dicamba or/ 3,6-dichloro-2-methoxybenzoic acid. I mention this because cold water fish, specifically trout, are somewhat affected by this chemical. Nasty stuff those benzoic acids, causes burns and loss of appetite but that is of course at higher concentrations. Fortunately it usually just breaks down to water and CO2.
As with all herbicides, everyone throws a fuss because of bio-accumulation (as PF mentioned).
