Spraying weeds in the lake

We woke to a very still cool morning beside the lake.  In fact it was quite cold in the caravan which is better than being too hot. I got up early and took photos of the mist rising off the water (extra) thinking I had my blip until some people from Environment Waikato turned up in their hi viz vests and told all the campers that a helicopter was coming up the lake shortly to spray the lake weeds. We had lots of questions about the effect on the bird life, fish and how toxic it was but were reassured it was all OK and given a web site to read up on it. We didn't have time to pack up and leave as we could hear the helicopter working further down the lake and were told it was about 10 minutes away. It was very impressive watching the helicopter flying so low and there certainly was no spray drift but we could smell it.  I think this is the end of my swimming in the lake this season.