Latex balloons take a long time to biodegrade on land and even longer in water. The string is an entanglement risk until it biodegrades which will also take time. In any event the pieces are in the environment long enough for animals to mistake for food or otherwise litter up to hundreds of miles away.

They could go one step better and take the strings off – then releasing the balloons by opening some kind of netting that stays at the launch site. This is not a complete solution but would be one more step in the right direction.

I’m for ending all helium balloon releases entirely as soon as possible.