Monsanto (RoundUp) claims that glyphosate does not cause reproductive complications. However, tests with rabbits have determined adverse effects on semen and sperm quality. Other studies at high dosages have reported problems such as decreased litter size and reduced sperm counts in rats.
Truth about Chemical Spraying: Herbicides do NOT remove biomass (The biomass in an ecosystem includes the mass of all living and dead organic matter) from your pond. Spraying weeds actually contributes MORE matter into the water by killing them and leaving them to become muck and sludge.
In order for a retention pond to operate as efficiently as possible, any vegetation should be maintained at a height that allows for inspection for things like nuisance animal burrows, developing sinkholes, and wetness along the fill embankments. One of the most common mistakes in the upkeep of retention ponds is not mowing critical areas because they are at a steep angle, or neglecting to mow altogether. Maintenance is vital for a properly functioning retention pond.